Kawasaki Rotary Valve Engines - FAQ
This page is a FAQ or Frequently Asked Questions specifically about models that feature Kawasaki's 2 stoke rotary valve engines. It would seem there was no centralized repository for specifications, technical, tuning, how to and repairs that are unique to a rotary valve engine. While the information contained here is specific to each model discussed, a lot of the information is universal enough to apply to other brands that used this engine design in motorcycles, PWC's and snowmobiles. Early Yamaha motorcycles had rotary valve 2 stroke engines as did Suzuki, however they mostly abandoned the design by the late 60's in favor of piston port or reed valve 2 strokes. Another notable brand was CAN-AM, but they are more outliers as it was Kawasaki that really developed the rotary valve 2 stroke to probably its fullest potential. As always, consult the appropriate manual for your model for even more detailed information. This site is designed to help de-mystify certain common questions and explain on things the manual does not. This page will discuss these Kawasaki models GA1A, GA2A, G3SSA, G3TRA, MC1, MC1M, G4TR, G5, G31MA. F1, F1TR, F2, F2TR, F3 (Bushwacker), F5 (Big Horn), F6, F7, F8 (Bison), F81M, F9, 81LA
 Typical Rotary valve disc
What is a rotary valve?
A rotary valve as used in a 2 stroke motorcycle engine is simply a round disc with a specific cutout around the perimeter that is keyed to the crankshaft. The purpose is to function as a means of closing off the intake tract at a specific time and duration. Think of it similar to how a traditional intake poppet valve in a 4 stroke engine controls the incoming air/fuel mix into the cylinder. The biggest difference is that the intake on most* rotary valve style engines is on the right side, just above the crankshaft with a straight shot right into the crankcase. *Some notable exceptions being Kawasaki twins A7, A1 (Avenger, Samurai), vintage Can-Am/Rotax engines are on the left side, older 2 stroke See-Doo and other PWC 2 stroke twins can have them on the front transverse to the crankshaft driven by a set of bevel gears. Irregardless the function and principle is the same. 
Rotary valve engine with clutch cover and carburetor installed
|
Rotary valve disc installed, cover removed. Intake port visible.
Rotary valve engine with carburetor cover installed
|
Pros & Cons As with any engine design there are pros & cons and a rotary valve engine is no different. Below are the main ones
|
Pros:
Precise control of the intake timing versus other 2 stroke designs. Straight intake flow directly into the crankcase for efficiency Lower engine center of gravity with side mounted carb. Intake timing can be asymmetric in respect to exhaust port timing. Crankcase pressure and thus scavenging can be improved. |
Cons:
More complex design, more sealing surfaces and chances for air leaks. Intake runners are very short and can hinder intake velocity for certain applications. Engines are wider because the carburetor(s) need to be mounted on the side(s) of the engine. Rotary Valve Disc can experience wear and need to be replaced Generally nosier versus piston port & reed valve designs. (subjective) |
Kawasaki Model identification and overviews
Single cylinder (90 cc - 350 cc)
Use the slider, pick the displacement and see information/specs/tuning about the models within that displacement
My Kawasaki MC1M
90 CC
Kawasaki GA1A, GA2A, G3SSA, G1, G1L, G1DL, G1TRL, MC1, MC1M
J1, J1L, J1T 85cc, rare J1M (motocross)
All the 90cc engines, generally speaking, share a lot of internal and external parts. Later models that superseded earlier models usually have some subtle changes to either improve performance OR durability. It is within these subtleties of specifications where certain models can be harder to find specific parts.
The 85cc models serve as a precursor to the 90cc category. These were Kawasaki's first rotary valve bikes for the U.S. market. There is some homage in design language that began with the early "J" bikes that carry through. That said they share very little in the way of interchangeable parts. Some of these early bikes required pre-mixing of the oil and gas. See specific detail notes below for each model & year.
* Super-Lube (can be disabled for premix use, click to learn more)
Kawasaki 90cc models frame & engine identification (below)
The frame and engine numbers indicate the beginning of the sequence for that model year. The next model year starts the sequence after the previous model years number.
*it is common for frame and engine numbers to mis-match within a given year
Kawasaki GA1A, GA2A, G3SSA, G1, G1L, G1DL, G1TRL, MC1, MC1M
J1, J1L, J1T 85cc, rare J1M (motocross)
All the 90cc engines, generally speaking, share a lot of internal and external parts. Later models that superseded earlier models usually have some subtle changes to either improve performance OR durability. It is within these subtleties of specifications where certain models can be harder to find specific parts.
The 85cc models serve as a precursor to the 90cc category. These were Kawasaki's first rotary valve bikes for the U.S. market. There is some homage in design language that began with the early "J" bikes that carry through. That said they share very little in the way of interchangeable parts. Some of these early bikes required pre-mixing of the oil and gas. See specific detail notes below for each model & year.
* Super-Lube (can be disabled for premix use, click to learn more)
Kawasaki 90cc models frame & engine identification (below)
The frame and engine numbers indicate the beginning of the sequence for that model year. The next model year starts the sequence after the previous model years number.
*it is common for frame and engine numbers to mis-match within a given year
|
J1, J1D, J1L 1965-1968 (85cc)
*low pipe models Engine No. (J1) J1E00001- (J1L) LFE0000l- Frame No. (J1) 100001- (J1L) J1L-00001- Oil system: J1 & JD (1965-66) require premix. 20:1 They had no oil injection system *these bikes probably had a lot of engine failures The J1L (1967-68) incorporated (then new) Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
J1T, J1TL 1965-1967 (85cc)
*high pipe models Engine No. (J1T) 00001- (J1TL) 00001- Frame No. (J1T) JlT000l - (JITL) JlTL00001 - Oil system: J1T (1965-66) require premix. 20:1 They had no oil injection system *these bikes probably had a lot of engine failures The J1TL (1967) incorporated (then new) Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
J1TR, J1TRL 1966-67 (85cc)
*trail version of the J1T Engine No. (J1TRL) 00001- Frame No. (J1TRL) J1RL00001- Features a unique overlay rear sprocket for 2 different final drive gearing. Upswept exhaust, engine skid plate, knobby tires to indicate trail prowess Oil system: J1TR (1966) require premix. 20:1 They had no oil injection system *these bikes probably had a lot of engine failures The J1TRL (1967) incorporated (then new) Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
J1M 85cc 1966
*very rare motocross version of the J1 This bike might have been the inspiration for the later 100cc G31M Centurion. The J1M was a warmed over J1 increasing horsepower from the base 8 to 11. Through different porting and expansion chamber exhaust. Oil system Premix only-15:1 |
|
G1, G1L, G1DL,G1TRL 1967-1969
*evolution of the J1, bored to 90cc Engine No. (G1) 100001- (G1L) 300001- Frame No. (G1) 1000001- (G1L) 1100001- Oil system G1 (1967) require premix. 20:1 They had no oil injection system *these bikes probably had a lot of engine failures G1L, G1DL, G1TRL (1968-69) incorporated (then new) Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G1M 1967-1968
*evolution of the J1M, bored to 90cc Engine No. 400001- Frame No. G1-400001- Like the J1M, the G1M is a warmed over 90cc G1 engine featuring an expansion chamber exhaust. This results in a horsepower increase from 8.2 to 16. This is also a rare bike that not many were produced. The frame number indicates it used the exact frame off the line of the G1 suggesting a mid 67 year production. Oil System: Premix only 15:1 |
|
GA1 1969-1970
*evolution of the G1 Engine No. GAE-000001- Frame No. GA-200001- The GA1 is a more developed version of the G1. Notable features include more horsepower from 8.2 to 10.5 from revised porting and carburation. Also improved suspension using nitrogen gas-filled shocks over previous models. Also the first appearance of a tubular frame over the previous 2 piece pressed steel frames. Oil system: Kawasaki's Super-Lube |
|
GA1A 1971-1974
*successive model to the GA1 Engine No. GAE-000000 Frame No. GA-200000 No successive frame or engine number sequence for year over year. Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
GA2 1969-1970
*5 speed version of the GA1, GA1A otherwise identical Engine No. GAE-200001- Frame No. GA-200001- Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
GA2A 1971-1974
*successive model of the GA2 Engine No. GAE-200000 Frame No. GA-200000 Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
GA3 1969-1970
*Street scrambler version of the GA2 Engine No. GAE-200000 Frame No. GA-200000 The GA3 marks the appearance of a "street scrambler" styling. Upswept exhaust and a universal "trials" tread tire on the front only communicates some intended light off-road use. Retains the turn signals of the GA2 and is identical in the mechanicals to the GA2. Can be confused with the 1969 G3TR Bush Master. Use engine and frame numbers to confirm model Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G2S 1974
*one year only model Engine No. G8E-000000 Frame No. G8-000001- Mechanically identical to the GA1 with updated styling. An odd offering being sold against the GA2 & GA1. Notable differences are the 4 speed rotary shift, versus a 5 speed return shift. Also an advertised rated .5 less horsepower at a lower rpm. Possibly a transition model for coming importation emission standards in the this category. Rare and often mis-identified as a G2T visually. Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
*Remarks misprint
|
G2T 1974-1976
*more developed version of the GA2 Engine No. GSE500000 Frame No. G8-500001- Mechanically identical to the GA2. A successive model to the G2S briefly sold along side for 1974. Also advertised rated .5 less horsepower at a lower rpm. *Only minor stylistic and detail changes from the GS2, but shares more commonality with the 5 speed GA2. *identification guide has a mis-print in the "Remarks" Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
KC90 was a Euro/Asian spec model. Did not appear in the US
|
KC90 1977-*1983
*model designation change from the G2T 1977 KC90-A1 Engine No. G8E511601- Frame No. GF-503901- *1978 KC90-A2 *1979 KC90-A3 *1980 KC90-C1 *1980 KC90-C2 *1981 KC90-C3 1982 KC90-C4 Engine No. G8E519801- Frame No. GF-512101- 1983 Engine No. G8E520251- Frame No. GF-512501- Mechanically identical to the G2T and later 90cc models. Stylistic updates each model year. *missing information Contact me if you have information |
|
G3TR Bush Master 1969
*trail oriented version of the GA2 & GA3 Engine No. G3E00001- Frame No. GA-200001- Can often be confused with the 1969 GA3 as it was sold along side it. Notable differences are the "Bush Master" moniker, no standard turn signals. It also came with knobby tires both front and rear versus the GA3 only having a "trials" tread on the front and traditional "street" tread on the rear. Use engine and frame numbers to confirm model |
|
G3TR 1970
*minor stylistic revision Engine No. G3E00000 Frame No. GA-20000 Stylistic update in the way of the tank decal and oil tank. Also this uses a sealed beam headlight versus a bulb like in older models. Fuel tank styling usually makes the 1970 G3TR less confused with the 1969 GA3 |
|
G3SS 1969-1970
*low pipe street only model Engine No. GAE 000000 Frame No. GA-000000 Shares common parts to the GA2 bikes. Stylistically different. Tank color is different between years Pastel Blue (69) & Candy Blue (70) Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G3SSA 1971
*minor styling changes Engine No. GAE268738- Frame No. GA-268327- Updated styling otherwise unchanged Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G3SSB 1972
*minor changes Engine No. GAE280935- Frame No. GA-306826- Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G3SSC 1973
*minor updates Engine No. GAE292961- Frame No. GA-329103- Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
G3SSD 1974
*minor updates Engine No. G8E507550- Frame No. GA-355001- Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
G3SSE 1975 *displacement increased to 100cc (see next tab)
|
MC1 1973
*replacement of the "street scrambler" with "enduro" styling features Engine No. MCE000001- Frame No. MC-000001- First year for the 90cc class to feature "enduro" styling and features. Communicating on and off road performance. Shares some mechanical parts with the G1/2/3-series however engine internal specs differ slightly. Rated horsepower is down from 10 to 6.6 rated at a lower rpm. Possibly to increase torque and reliability. Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
MC1A 1974
*minor revisions Engine No. MCE006966- Frame No. MC-006946- Casting change to the left side (ignition) engine cover, however it will fit 1973. Differently shaped seat. Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
|
MC1B 1975
*minor revisions Engine No. MCE018500- Frame No. MC-018500- Rear tire width size increased from 2.75 to 3.00. Diameter remains unchanged. Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
First entry level motocross offering aimed at young riders
|
MC1M 1974
*motocross version of the MC1 "enduro" Engine No. MCE500001- Frame No. MC-500001- The MC1M is a MC1 stripped of lights and charging system. Plastic fenders and number plates added for competition and to reduce weight. Engine & suspension are identical to the MC1 "enduro" and so is performance. This model was designed for young entry level competition unlike previous 85/90cc (J1M/G1M) motocross models which were aimed towards adults. See my MC1M restoration here |
|
MC1MA 1975
*stylistic update Engine No. MCE509500- Frame No. MC-508500- Identical to the 1974 model with only a stylistic update Oil system: Kawasaki's Super-Lube Ignition: Contact Breaker Point (can run without battery, see diagram) Points gap: 0.3mm~0.4mm ALL Models Transmission oil: SAE 10W30 or 30W |
Typical breaker point ignition (bare minimum for engine to run)
Kawasaki G4TR
100 CC
D1, G3TRA, G4TR (Trail Boss), G5, KE100, KM100, KH100, G31M (Centurion)
All the 100cc engines, generally speaking, share a lot of internal and external parts. Later models that superseded earlier models usually have some subtle changes to either improve performance OR durability. Some of these 100cc models also are very closely related to some of the 90cc models. Some of the 100cc models share lower end and engine covers with the 90cc models. It is within these subtleties of specifications where certain models can be harder to find specific parts.
The one unique feature on the G4TR is the HI/Lo range transmission, meaning it has a theoretical 10 speeds to choose from. A tell tale sign is an extra cover bolted to the countershaft cover that house the HI/Lo range selector mechanism.
2 stroke Oiling System: Super-Lube (can be disabled for premix use, click to learn more), G31M was designed without an oil pump, premix only
Ignition: Contact Breaker Point (see diagram below)
Points gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or 30 (D1, G3TRA), 30 or ATF (G4TR, G5, G31M, KE100, KM100)
It should be noted that the G31M Centurion has few similarities with these other 100cc bikes, most of the internal parts are unique including the plated cylinder (for reduced friction and heat dissipation), thus giving it the 18.5 hp (claimed) versus all the other models roughly 11 horsepower. One of the standout features is the auxiliary air intake screen cut into the side of the carburetor cover (similar to the F81M 250cc)
D1, G3TRA, G4TR (Trail Boss), G5, KE100, KM100, KH100, G31M (Centurion)
All the 100cc engines, generally speaking, share a lot of internal and external parts. Later models that superseded earlier models usually have some subtle changes to either improve performance OR durability. Some of these 100cc models also are very closely related to some of the 90cc models. Some of the 100cc models share lower end and engine covers with the 90cc models. It is within these subtleties of specifications where certain models can be harder to find specific parts.
The one unique feature on the G4TR is the HI/Lo range transmission, meaning it has a theoretical 10 speeds to choose from. A tell tale sign is an extra cover bolted to the countershaft cover that house the HI/Lo range selector mechanism.
2 stroke Oiling System: Super-Lube (can be disabled for premix use, click to learn more), G31M was designed without an oil pump, premix only
Ignition: Contact Breaker Point (see diagram below)
Points gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or 30 (D1, G3TRA), 30 or ATF (G4TR, G5, G31M, KE100, KM100)
It should be noted that the G31M Centurion has few similarities with these other 100cc bikes, most of the internal parts are unique including the plated cylinder (for reduced friction and heat dissipation), thus giving it the 18.5 hp (claimed) versus all the other models roughly 11 horsepower. One of the standout features is the auxiliary air intake screen cut into the side of the carburetor cover (similar to the F81M 250cc)
The unique G31M Centurion, shares very few parts with other models
Typical contact breaker point ignition
Kawasaki G4TR wiring diagram
Kawasaki KE100 Wiring diagram
Kawasaki KH100 wiring diagram
Kawasaki F6
125 CC
B1LA, F6, KS125, KD125, KE125
The F6 is the more popular version of the 125cc bikes. The F6 shares very little if almost nothing with the B1LA. It shares nearly everything with the F7 as it is just an F7 lower end with a smaller piston and cylinder. It would appear that the F7 was developed first and then downsized to fit a model into the 125cc category at the time. The B1 has electric start, a unique feature for a 2 stroke motorcycle. The KS125/KE125 was similar to the F6 but with a bit lower horsepower, thus they don't share too much in the way of the internals.
2 stroke Oiling System: Super-Lube (can be disabled for premix use)
Ignition: Contact Breaker Point (see diagram)
Point gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or 30 (All Models)
B1LA, F6, KS125, KD125, KE125
The F6 is the more popular version of the 125cc bikes. The F6 shares very little if almost nothing with the B1LA. It shares nearly everything with the F7 as it is just an F7 lower end with a smaller piston and cylinder. It would appear that the F7 was developed first and then downsized to fit a model into the 125cc category at the time. The B1 has electric start, a unique feature for a 2 stroke motorcycle. The KS125/KE125 was similar to the F6 but with a bit lower horsepower, thus they don't share too much in the way of the internals.
2 stroke Oiling System: Super-Lube (can be disabled for premix use)
Ignition: Contact Breaker Point (see diagram)
Point gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or 30 (All Models)
Typical Breaker point ignition
Kawasaki F6 wiring diagram
Kawasaki F7 175
175 CC Models
F2, F2TR, F3 (Bushwacker), F7, KE175, KD175 (rotary valve models)
F1, F1TR (piston port models)
Probably the most recognized and well known of the 175's is the F7, however a few models preceded it paving the way for the F7's (claimed) 21 hp. Unlike some of the other smaller displacements the F7 shares very little with the previous models. It could be considered that the F7 is a highly refined and more developed version of the F3 even thought they share almost nothing. The KE175 is a lower horsepower version of the F7 it shares a few things like the crankshaft and connecting rod assembly, but the pistons are different. Read here about the "drain pump" on the front of the crankcase that can fail causing jetting problems and even piston seizure. Applies to the F7 & KD175/KE175.
Kawasaki 175cc models frame & engine identification (below)
The frame and engine numbers indicate the beginning of the sequence for that model year. The next model year starts the sequence after the previous model years number.
*it is common for frame and engine numbers to mis-match within a given year
F2, F2TR, F3 (Bushwacker), F7, KE175, KD175 (rotary valve models)
F1, F1TR (piston port models)
Probably the most recognized and well known of the 175's is the F7, however a few models preceded it paving the way for the F7's (claimed) 21 hp. Unlike some of the other smaller displacements the F7 shares very little with the previous models. It could be considered that the F7 is a highly refined and more developed version of the F3 even thought they share almost nothing. The KE175 is a lower horsepower version of the F7 it shares a few things like the crankshaft and connecting rod assembly, but the pistons are different. Read here about the "drain pump" on the front of the crankcase that can fail causing jetting problems and even piston seizure. Applies to the F7 & KD175/KE175.
Kawasaki 175cc models frame & engine identification (below)
The frame and engine numbers indicate the beginning of the sequence for that model year. The next model year starts the sequence after the previous model years number.
*it is common for frame and engine numbers to mis-match within a given year
|
F1 1966
*single year model, not a rotary valve engine Engine No. 100001- Frame No. F1-10001- 2 stroke Oiling System: Super-Lube Ignition: Contact Breaker Point Gap: 0.03mm~0.4mm Transmission oil: SAE 10W30 or ATF |
|
F1TR 1966
*single year model, Not a rotary valve engine Engine No. 200001- Frame No. F1-20001- 2 stroke Oiling System: Super-Lube Ignition: Contact Breaker Point Gap: 0.03mm~0.4mm Transmission oil: SAE 10W30 or ATF |
|
F2 1966-1969
*sequence is not broken out by model year Engine No. 300001- Frame No. F21-00001- 2 stroke Oiling System: Super-Lube Ignition: Contact Breaker Point Gap: 0.03mm~0.4mm Transmission oil: SAE 10W30 or ATF |
|
F2TR 1966-1967
*sequence is not broken out by model year, trail version of the F2 Engine No. 500001- Frame No. F22-00001- 2 stroke Oiling System: Super-Lube Ignition: Contact Breaker Point Gap: 0.03mm~0.4mm Transmission oil: SAE 10W30 or ATF |
|
F3 Bushwacker 1968-1970
*sequence is not broken out by model year Engine No. F3E00001- Frame No. F3-100001- 2 stroke Oiling System: Super-Lube Ignition: Contact Breaker Point Gap: 0.03mm~0.4mm Transmission oil: SAE 10W30 or ATF |
|
F7 1971
Engine No. F7E00001- Frame No. F7F-00001- 2 stroke Oiling System: Super-Lube Ignition: CDI (see wiring & tests below) Transmission oil: SAE 10W30 or ATF |
|
F7 A 1972
Engine No. F7E 19268- Frame No. F7-25706- 2 stroke Oiling System: Super-Lube Ignition: CDI (see wiring & tests below) Transmission oil: SAE 10W30 or ATF |
|
F7 B 1973
Engine No. F7E44158- Frame No. F7-50556- 2 stroke Oiling System: Super-Lube Ignition: CDI (see wiring & tests below) Transmission oil: SAE 10W30 or ATF |
|
F7 C 1974
Engine No. F7E67001- Frame No. F7-73001- 2 stroke Oiling System: Super-Lube Ignition: CDI (see wiring & tests below) Transmission oil: SAE 10W30 or ATF |
|
F7 D 1975
Engine No. F7E90600- Frame No. F7-96287- 2 stroke Oiling System: Super-Lube Ignition: CDI (see wiring & tests below) Transmission oil: SAE 10W30 or ATF |
|
KE175 B1 1976
Engine No. KE175BE000001 - Frame No. KE175B-000001- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
|
KE175 B2 1977
Engine No. KE1758E011101- Frame No. KE1758-01 1 101- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
|
KE175 B3 1978
Engine No. KE175BE021001- Frame No. KE175B-021001- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
|
KD175 A1 1976
Engine No. KD175AE000001- Frame No. KD175A-000004- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
|
KD175 A2 1977
Engine No. KD175AE003601- Frame No. KD175A-003601- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
|
KD175 A3 1978
Engine No. : KD175AE006001- Frame No.: KD175A-006001- Ignition: CDI (see wiring & tests below) *not compatible with the F7 Transmission oil: SAE 10W30 or ATF |
Kawasaki KE175 wiring diagram
Kawasaki F1, F2, F3, F4, F21M
Kawasaki F7 magneto testing
Kawasaki F7 Wiring diagram
Typical Breaker point ignition
My F81M replica
250 CC
F4 (Sidewinder), F21M (Green Streak), F8 (Bison), F81M
The F4 and F21M both share quite a bit of engine and internals, just as the F8 and F81M share a lot of the same parts. However the two groups do not share anything between the two. It could be considered that the F8/F81M engines are more developed and refined versions of the F4/F21M. The F8/F81M share a lot with the larger 350cc F5 & F9 engines. Most parts are the same except for the piston and cylinder. Fun fact! The muffler/expansion chamber on the F81M is the same one that was offered in the "Speed Kit" for the F5 (350cc) Big Horn
2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates right side crank bearing) Except F81M designed for pre-mix only
Ignition: Contact Breaker Point
Point gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or ATF (All Models)
F4 (Sidewinder), F21M (Green Streak), F8 (Bison), F81M
The F4 and F21M both share quite a bit of engine and internals, just as the F8 and F81M share a lot of the same parts. However the two groups do not share anything between the two. It could be considered that the F8/F81M engines are more developed and refined versions of the F4/F21M. The F8/F81M share a lot with the larger 350cc F5 & F9 engines. Most parts are the same except for the piston and cylinder. Fun fact! The muffler/expansion chamber on the F81M is the same one that was offered in the "Speed Kit" for the F5 (350cc) Big Horn
2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates right side crank bearing) Except F81M designed for pre-mix only
Ignition: Contact Breaker Point
Point gap: 0.3mm~0.4mm
Transmission oil: SAE 10W30 or ATF (All Models)
Kawasaki F8 Bison wiring diagram
Kawasaki F81M Wiring diagram
My Barn Fresh Restoration Kawasaki F5
350 CC (Big Horn)
F5, F9
The Kawasaki Big Horn! Probably one of the most notorious of the rotary valve singles made by Kawasaki. Technically speaking only the F5 (1970) and F5A (1971) are Big Horn's as only those 2 years were they marketed using the "Big Horn" on marketing materials. The F5A would extend to have "350E" designation in marketing literature to denote "Enduro" just like the rest of the model lineup in 1971. Also the "Power Pak" or "Speed Kit" was only available for 1970-71, and dropped for the F9. However all parts are compatible with the F9. The "Speed Kit" claimed to raise the horsepower from the advertised 33 to 45. Fun fact! The muffler/expansion chamber, rotary valve disc, in the kit is the same one that came stock on the F81M. This is also true for the carburetor cover and air filter cutout on the side. This was similar to Yamaha's GYT Kit for the DT1. The F9 shares a lot with the F5 but there are few differences in engine covers and a few internal parts. However most things interchange and as a whole the F9 could be considered a more developed version of the F5 but mostly in other ways aside from the engine. Read here about the unique design for evacuating fuel/water from the carburetor chamber on the F5/F9.
2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates right side crank bearing)
Ignition: CDI
Transmission oil: SAE 10W30 or ATF
F5, F9
The Kawasaki Big Horn! Probably one of the most notorious of the rotary valve singles made by Kawasaki. Technically speaking only the F5 (1970) and F5A (1971) are Big Horn's as only those 2 years were they marketed using the "Big Horn" on marketing materials. The F5A would extend to have "350E" designation in marketing literature to denote "Enduro" just like the rest of the model lineup in 1971. Also the "Power Pak" or "Speed Kit" was only available for 1970-71, and dropped for the F9. However all parts are compatible with the F9. The "Speed Kit" claimed to raise the horsepower from the advertised 33 to 45. Fun fact! The muffler/expansion chamber, rotary valve disc, in the kit is the same one that came stock on the F81M. This is also true for the carburetor cover and air filter cutout on the side. This was similar to Yamaha's GYT Kit for the DT1. The F9 shares a lot with the F5 but there are few differences in engine covers and a few internal parts. However most things interchange and as a whole the F9 could be considered a more developed version of the F5 but mostly in other ways aside from the engine. Read here about the unique design for evacuating fuel/water from the carburetor chamber on the F5/F9.
2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates right side crank bearing)
Ignition: CDI
Transmission oil: SAE 10W30 or ATF
Kawasaki Big Horn F5 & F9 Model Year Identification chart: *it is common for frame and engine numbers to mis-match
Year/model Frame# (range) Engine# (range)
1970 F5 frame# F5-00001-07182 Eng# F5E00001-07268
1971 F5 frame# F5-07183-13633 Eng# F5E07269-13665
1972 F9 frame# F5-30402-42370 Eng# F5E13666-24484
*73-75 frames begin using F9 prefix, Engine #'s continue to use F5E prefix
1973 F9A frame# F9F-00001-08999 Eng# F5E24485-31999
1974 F9B frame# F9F-09001-15499 Eng# F5E32001-38599
1975 F9C frame# F9F-15500-22299 Eng# F5E38600-45451
Year/model Frame# (range) Engine# (range)
1970 F5 frame# F5-00001-07182 Eng# F5E00001-07268
1971 F5 frame# F5-07183-13633 Eng# F5E07269-13665
1972 F9 frame# F5-30402-42370 Eng# F5E13666-24484
*73-75 frames begin using F9 prefix, Engine #'s continue to use F5E prefix
1973 F9A frame# F9F-00001-08999 Eng# F5E24485-31999
1974 F9B frame# F9F-09001-15499 Eng# F5E32001-38599
1975 F9C frame# F9F-15500-22299 Eng# F5E38600-45451
Below are some notable differences between model years for the Big Horn F5 and the F9
Model designation Key:
F5 = 1970
F5A = 1971
F9 = 1972-1975 (A,B,C for respective years 73-75)
The F5 (first year) was produced in relatively limited numbers at aprox. 7,000 units. Compared to Yamaha producing almost 3 times as many RT1's (360cc).
Early engines had a different kick start mechanism and lever as well as a smaller big end rod bearing size. A changed mid year with engine numbers after 07268 (mid 1970 year change) had larger (more reliable) big end rod bearings. Newer crankshafts will fit earlier engines. My early F5 bike has engine number 02300 and a build date of February 1970
F5 Control cables (clutch, rear brake, and tach) were silver. F5A/F9 (1971/1972-75) cables were black
F5 and F5A cylinders and heads are natural aluminum color, The F9 has black painted cylinders and heads
F5 ,F5A uses a 32mm (large body) carburetor, the F9 uses a 30mm (small body) carburetor. This accounts for the lower HP numbers for the F9, but made the bike a bit mellower which made for a better riding bike.
Carburetor cover and control cable boot are unique to the F5. F5A and later (F9) used a different cover and boot that improved sealing. This design changed twice.
F5 had Painted graphics. Later F5A and F9 used vinyl decals much like other manufacturers.
Handlebar is chrome and bend is unique to the F5 and F5A, The F9 used a different bend and came in black
.
Speedometer and tachometer are unique to the F5 with chrome trim rings. F5A gauges had rubber hoods to reduce glare, F9 the gauges changed slightly.
F5 chain guard is silver. The F5A is black, the F9 is black and of a different design.
F5, F5A and F9, F9A featured the Hatta forks, F9B and C changed to the more conventional forks similar to the F11 (1973 piston port 250cc) but still featured the adjustable pre-load, but did not have the adjustable axle position.
Foot pegs are rubber, round, spiked unique to the F5,and F5A. The F9 had a more conventional flat style rubber.
Muffler heat shield is chrome on the F5, black on the F5A both mufflers require optional bolt on spark arrestors. Without the spark arrestor the exhaust exits right before the rear shock. The F9 completely redesigned the muffler with a built in spark arrestor and bends around the rear shock exiting after the shock.
Alloy (aluminum) wheels were featured on the F5 and F5A The alloy wheels were soft (but light) and had a groove or lip that held mud when riding in muddy conditions. The F9 had chrome steel wheels that were heavier but more durable. They also had a more conventional flat profile that shed mud better. The F9 used heavier duty spokes as well.
Front brake drum design on the F5, F5A ,F9, F9A is lighter and compared to the F9B/C. It also uses a brake drum strut. The F9B/C front brake drum dimensionally larger and of a different design on the outside but uses the same brake shoes. It also features a brake wear indicator and a different brake arm actuator and the F5 brake drum strut was replaced with cast in slots that fit into tabs cast into the lower end of the forks. Thus lower fork tubes and/or front wheels are not interchangeable between the two groups of models.
Lightweight aluminum fenders on the F5 and F5A, The F9 changed to steel for durability. The physical designs of the fenders are identical though.
Rear tail lights are different on the F5 versus the F9. The F9 taillight is much heavier.
Model designation Key:
F5 = 1970
F5A = 1971
F9 = 1972-1975 (A,B,C for respective years 73-75)
The F5 (first year) was produced in relatively limited numbers at aprox. 7,000 units. Compared to Yamaha producing almost 3 times as many RT1's (360cc).
Early engines had a different kick start mechanism and lever as well as a smaller big end rod bearing size. A changed mid year with engine numbers after 07268 (mid 1970 year change) had larger (more reliable) big end rod bearings. Newer crankshafts will fit earlier engines. My early F5 bike has engine number 02300 and a build date of February 1970
F5 Control cables (clutch, rear brake, and tach) were silver. F5A/F9 (1971/1972-75) cables were black
F5 and F5A cylinders and heads are natural aluminum color, The F9 has black painted cylinders and heads
F5 ,F5A uses a 32mm (large body) carburetor, the F9 uses a 30mm (small body) carburetor. This accounts for the lower HP numbers for the F9, but made the bike a bit mellower which made for a better riding bike.
Carburetor cover and control cable boot are unique to the F5. F5A and later (F9) used a different cover and boot that improved sealing. This design changed twice.
F5 had Painted graphics. Later F5A and F9 used vinyl decals much like other manufacturers.
Handlebar is chrome and bend is unique to the F5 and F5A, The F9 used a different bend and came in black
.
Speedometer and tachometer are unique to the F5 with chrome trim rings. F5A gauges had rubber hoods to reduce glare, F9 the gauges changed slightly.
F5 chain guard is silver. The F5A is black, the F9 is black and of a different design.
F5, F5A and F9, F9A featured the Hatta forks, F9B and C changed to the more conventional forks similar to the F11 (1973 piston port 250cc) but still featured the adjustable pre-load, but did not have the adjustable axle position.
Foot pegs are rubber, round, spiked unique to the F5,and F5A. The F9 had a more conventional flat style rubber.
Muffler heat shield is chrome on the F5, black on the F5A both mufflers require optional bolt on spark arrestors. Without the spark arrestor the exhaust exits right before the rear shock. The F9 completely redesigned the muffler with a built in spark arrestor and bends around the rear shock exiting after the shock.
Alloy (aluminum) wheels were featured on the F5 and F5A The alloy wheels were soft (but light) and had a groove or lip that held mud when riding in muddy conditions. The F9 had chrome steel wheels that were heavier but more durable. They also had a more conventional flat profile that shed mud better. The F9 used heavier duty spokes as well.
Front brake drum design on the F5, F5A ,F9, F9A is lighter and compared to the F9B/C. It also uses a brake drum strut. The F9B/C front brake drum dimensionally larger and of a different design on the outside but uses the same brake shoes. It also features a brake wear indicator and a different brake arm actuator and the F5 brake drum strut was replaced with cast in slots that fit into tabs cast into the lower end of the forks. Thus lower fork tubes and/or front wheels are not interchangeable between the two groups of models.
Lightweight aluminum fenders on the F5 and F5A, The F9 changed to steel for durability. The physical designs of the fenders are identical though.
Rear tail lights are different on the F5 versus the F9. The F9 taillight is much heavier.
Kawasaki F5 & F9 right side crank bearing
|
Crankshaft bearings for the Kawasaki F5 & F9 Big Horn can be elusive to find. The right side crank bearing for the F5 & F9 is a unique bearing with a machined shoulder (see picture). Below are the part numbers and where to buy it.
Right side bearing part# 92045-016 (buy it here) OR HERE (Amazon link) FAG bearing part# 6306-C3 Left side bearing part# 601B6305 which is much easier to find as it is more common. 92045-01 |
Notice the "shoulder" on the right side bearing, this fits a machined part of the case
Kawasaki F5 & F9 magneto test
80CC
KD80 1975-1987
The smallest of the rotary valve displacement bikes. These bikes are largely built off of the internals of the 90cc class of bikes. See 90cc tab for more elaborate details and lineage. These bikes share nothing with the KX80, which is part of the piston/reed valve KX line of motorcycles.
KD80 1975-1987
The smallest of the rotary valve displacement bikes. These bikes are largely built off of the internals of the 90cc class of bikes. See 90cc tab for more elaborate details and lineage. These bikes share nothing with the KX80, which is part of the piston/reed valve KX line of motorcycles.
|
KD80A 1975
*motocross version Engine No. KD080AE000001- Frame No. KD080A-000001- Smaller displacement version of the MC1M. This model was aimed at young or entry level competition riders. Shares a lot with the MC1M and other 90cc models (see tab) |
|
KD80A1 1976
*minor updates Engine No. KD080AE002100- Frame No. KD080A-002100- Tank color and graphics only revision. See MC1M |
KD80A2 1977
*styling changes
First year for the plastic fuel tank
*1978
*1979
*missing information Contact if you have information
*styling changes
First year for the plastic fuel tank
*1978
*1979
*missing information Contact if you have information
|
KD80-M1 1980
*styling updates |
Twin Cylinder (250 cc - 350 cc)
|
250 CC
A1, A1SS (Samurai) Twin cylinder rotary valve engine. Carburetors are fitted to both sides of the engine. Shares a lot of parts with the bigger 350cc version the A7. 2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates crank bearings) Ignition: CDI |
|
350 CC
A7, A7SS (Avenger) Twin cylinder rotary valve engine. Carburetors fitted to both sides of the engine. Shares a lot of parts with the smaller 250cc version the A1 2 stroke Oiling System: Injecto-Lube (can NOT disable for premix use, lubricates crank bearings) Ignition: CDI |