i'm 32 yrs old, me and my dad were talkin shop, and he started to talk about how they did it "back in the day"...he brought up his green streak...said it was the quickest bike he ever rode....i would love to find one and fix it up for him...any ideas on where to look for one?what kind of $$$ would i be looking at? if i could surprise him with one he would shit :) any suggestions are greatly appreciated...thanks

Not everyone is going to know what a 1971 Kawasaki green streak is, if you provide some more information (dirt bike, street bike, flattracker, etc.), how many cc engine size, 2-stroke or 4-stroke, you'll probably get a lot more responses and help in your search.

The green streak was a two stroke and a 250 I believe. IT was an absolute beast. I think it made about 4 hp to about 4500 rpm, then it went to about 49 from 4500 to 7500.

OMG!!! I had a '71 Kaw ...I believe the model designation was an F81M. It was my first 2/ dirtbike, traded in my trusty old 441VS on it. Gave up trying to keep up with the rapidly improving 2/ with that old thumper. Might have some pics of mine I can scan.

It was a 250cc single with they very unusual for a dirt bike, rotary valve induction. Rotaries were one thing on GP bikes, another thing on a dirtbike. They had the then new Hatta front forks which gave you multiple adjustments over the traditional front forks. It was also set up so that the brake and shifter could be mounted on either side!!. Hadnling as with most Asian bikes was its week point, but Shawn is right about the power plant.......explosive power....when it hit better be hangin on and pointed where you want to go.

At teh same time I had an ?-F8, I believe it was......the 250 DualSport/Enduro street legal version. Comparing both of them, we noted the F8 ignition was a bolt no conversion to teh F81M. The F81M had a very tiny flywheel with external coils, while the enduro had the large flywheel with the 'internal' coils...and lighting coils! So we put the enduro ingnition on the F81M. Worked great...got to remember this was in the days before there was any such thing as aftermarket flywheel weights. Softened the hit and made the bike much more managable/controllable, was actually faster with that ignition change. As an added bonus, we ere then able to add rudimentary lights to the MX bike and ride it in some cross country/enduros.



Might have a hard time finding one. They were not real common. I've only seen one decent one for sale in the last couple of yrs. FOr what I recall, it was all there and ran, but needed resto. I think it was around $800-900.

Man the old school bikes! I had one as well!This was back when the moto x
game was just kicking off hard here in the us,funny I was just looking at a 1971 tm 100 on ebay! It has to be one of the best looking vintage bikes I have seen in a while.Back to the green streak,What a beast, it would shake rattle and ROLL! :thumbsup:

I think the "Green Streak" was what my father-in-law raced in the early 70's as a professional flattracker. If memory serves me, he called it a 238cc. Would this be the same bike, or was there a 238 Kawi?

Prior to that he raced a Harley Davidson Sprint (250cc four stroke).

The 238 was the predecessor to the '71 250. I believe it was the F21m or F31m....too many grey cells ago to recall. Same engien layout...rotary valve 2/ single. I think they made them from around '66-'70..??



All the ones I recall had the typical Kaw green paint job with white tank panels. Never saw one that wasn't green.

he said his was the 238...had the front end stretched and changed the rear shock angle for motocross...i looked on ebay, couldn't find anything :(..i think it was originally for tt racing...thanks for the response

if i remember correctly the early f81 was in fact 238cc displacement, hence the 238 designation. i had a '74 f7 175...rotary valve induction. the carb was in the right hand case behind a cover...aggrivating when you had to play with jets, needle position, float height, etc. made lots of power down low, didn't like to rev. it had them crappy hatta forks filled with fish oil. they had maybe 3 inches of travel, flexed like bream buster fishing poles but we didn't care...we jumped, raced and rode them everywhere. we didn't know any better! my dad had the f9 bighorn 350, my younger brother had a g5 100 and my buddies had the f6 125. another pal had a g4tr with the hi-lo transmission and a g3tr "bushwhacker" 90. later on i had a g3ss 90 streetbike that was a blast to ride around town. i put a bassani pipe on it, had a skunk works engineering intake manifold, modified disc valve and rejetted it. powerband was like a lightswitch and made a wonderful noise as i rowed up thru the gears down main street at midnight. check out www.bradsbikes.net sometimes he has old kawi stuff for sale.

The 238 was the F21m. THe F81m was a new model and was the 250. Engines were similar in layout, but they are not the same engein, the F81M is not just a 238 F21m engine punched out a few more cc's. Take a look at the engine in the pics above.

I was 14 when my Dad bought me a '70-'71 baby Green Streak racer. 100cc of pure hell power. That thing would run with CZ 125's, TM125's, 175 street-turned-racer Kawi's, etc. Rotary induction, crome lined cylinder, cerani(SP?) forks, and footpeg mounts that would not stay tight! You should have heard that Dyno down swung pipe which was an add-on! Those were the days.

The Greenstreak was 238 cc and advertised as the "Greenstreak 238" Scrambler. It was marketed mainly as a TTscrambles/ flat tracker, mainly because motocross hadn't quite caught on and most American racing was TT/flat track. From what I remember they were fast, but like most Japanese bikes of the time, didn't handle as well as the Greeves, Bultaco and Ossa scramblers of the period. Motocross boomed soon after the Greenstreak was introduced, the European competition was selling better and the market was changing, Kawasaki dropped the 238 in favor of bikes that would sell to MXer's instead.
It shouldn't be too hard to find one in restorable condition. Try the AHRMA newsletter or AHRMA mart on their website. Place a "wanted " ad. Then there's always ebay. As for price, like all vintage bikes, it all depends on what the seller will accept and the buyer is willing to pay.
Good Luck.

The 238 Greenstreak is probably the rarest vintage Kaw. It was Kawasaki's first attempt at building a racer from the ground up. They are highly sought after in vintage circles and parts are non-existant. My vintage racing buddy has 3 in his collection (along with about 75 other vintage Kaws) and could probably retire on the offers that he gets for them.

If you are considering vintage racing, a Greenstreak would be a poor choice due to lack of parts and the high initial cost. If you are looking for one as a collector's item - then you'll have to look outside of the vintage circles and hopefully find someone who doesn't know what they have and would be willing to part with it.

I always thought it was wierd that Kawi had a fairly strong factory mx effort in the early 70's but their production mx effort was weak compared to the other Big 3. Korben, my buddy had one of those greenstreak "Centurion 100's". Made a ton of h.p. at screaming rpm's. I wanted one so bad!

I was 15 when the 238 was blasting everybody off the dirt! My bike was a 175 yamaha enduro. But a couple friends had green streaks. I rode one once at my friends house. It went absolutely sideways when it hit the pipe! The cool part was I was able to control it like a flattrakker! I currently own a crf450r which is way faster, but it isn't as fun as going sideways on that green streak!

My uncle had a 238 green streak engine in an American Eagle. I remember he had two gas tanks for it, one red and one blue. I think one was for motocross and the other for off road. I think he had two pipes as well. One was an up the other a down. I had to be about 4 or 5 years old at the time. He used to give me rides on it. He'd put me between him and the tank and told me to hold on to the cross bar. I remember being afraid of that bike because it was so loud! LOL Bruce

Old thread!

SInce the original dates, I came across a pic of me sitting on my '71 F81M, with the F8 enduro in the background:

Although I don't have any info on the 238, I do have some on the 100 and the F81M which was not the same as a Green Streak 238.

Here's the 100cc Green Streak Centurian. The first bike I ever owned was one of these.


Here's an engine closeup of the 100. Notice the airfilter doghouse on top of the engine.


Here's a picture of an F81M I just sold.


Notice the difference in the carb section on the F81M. They will say F81 on the frame and case too but the numbers won't match.

Ur scarin da chit outa me guys. Dad and his 2 brothers all had 350 Big Hornswhen I was a kid. A buddy had one of the 100 green streeks, very abrupt power band. The Green Streeks could be considered the Jap version of a Bultaco Astro, high output and tempermental, go like stink when the ran, would seize in an instant too, just like an Astro. Parts may be difficult to find I think because they were not made in large numbers.

The 100cc Centurions put out something like 18-21 H.P. if I remember. Notice the tiny stinger on the expansion chamber and the cool rubber foot pegs that liked to slip off when wet.