Brain Pick Time!!! was, OK One of you 2-stroke fans help me out here. Kaw F11 1973

You've probably already looked at the bike, but here goes anyway.

I've re-built most of the Kawasaki two stroke series. From the KV75(MT1) up to the triples.

The F11 is the best of the enduro bunch in my experience, right amount of 1970's power vs weight vs size. Decent suspension and handling for it's size. Not too heavy, not too light, etc and so on.

That being said, and I'm not trying to argue with anybody, but the F11 is a one and only. It is a piston port engine(carb is exterior to engine behind cyl), completely different than any of the rotary engined models(carb is hidden inside of right engine cover, about where your right foot will be on the brake lever). i.e, the F5, 6,7,8,9 etc. Which includes the 125, 175, the earlier F8 250 Bison and the F5(F9) bighorn. About the only things these engines have in common is that if you have a bad connecting rod, they come in on Ebay in the over $100.00 range every time. IF YOU CAN FIND ONE!!!!

The only parts the F11 shares with the F8 250 and the F5,F9 Bighorn is the crank bearings. The all important one is the right side, which is extremely hard to find and won't be a dollar under $25 if you can find one???? Not made of "Un0btanium" yet.........but it will be.

Other than that I can't think of a single major engine piece the other engines share with the F11.

Two stroke Kaws are the same as any other. Make sure you have compression and spark and it should go with a little carb and fuel tank cleaning.

Two stroke 101 course says make sure air filter is clean and the exhaust stinger isn't plugged. Either of the two problems or both cause for low power, or, won't run at all.

The F11 is nice in that it's an old fashioned, points, magneto ignition, unlike the F7 and F9 which are Capacitor ignition and require expensive boxes and pick up sender under the flywheel. The pick up coil for these under the flywheel, (Kawasaki calls them a "trigger coil" I think) are getting pricy and rare. Try Johnny's Vintage Motorcycle parts in OHio.
Get out your wallet.

If you got any questions let me know. I own two F11's but they aren't for sale. I really like them.

I fer-got. There is one common problem with all F-11's. Pull off the right forward engine cover, two screws, it covers the oil pump. The F11's utilizes two oil pump plasic lines, one goes to the inlet manifold just after the carb(in the airstream) and the other stays inside of this cover and goes to the right side crank bearing. The plastic tubes weren't designed right and they all have stress tension on them as installed. They eventually all break/crack and oil doesn't get inside the engine, and air does get into the engine, causing low oil and a lean mixture. Not a good situation. You have to pull the whole right side cover to change the bigger oil line going to the intake manifold. Not a hard job, but it requires draining the oil out of the transmission, new gasket, messy etc.

Post edited by: ThousandKaw, at: 2007/05/25 08:48

Post edited by: ThousandKaw, at: 2007/05/25 08:52

Post edited by: ThousandKaw, at: 2007/05/25 08:56

My bad. I was stuck on the rotary valve models, F5, F8, etc...

I would still snag one for $100, though. I really like the old 2-stroke enduros. They are what I, like many others around here, I'm sure, grew up on.

I just love the smell of pre-mix in the morning.

Well here she is.

Had to finish up the roadside find garden tiller before unloading the F11. Garden tiller has 4HP B&S engine with electronic spark trigger built into the coil Not the problem here. This one had a stuck exhaust valve. I mean STUCK. Took ATF soak and BFH to get it to move. Finally jacked it out of the block, polished stem, ran ream through guide, put her back together, rinsed tank with acid, put carb back on, and she runs!

Now for the F11 Photos. It's a $100 bike and I got it for $80 so don't laugh too hard.

Yes I saw...
Dent in tank.
I don't know where the points are
Has the key
Seat chewed
All plastic hoses broken
Petcock missing
Breaking waves sprocket
Broken compression release control
Crack in right front egine cover
...before buying.


Here are photos.
Thumbnail links to page with detail and selectable resolution.

Post edited by: Duck, at: 2007/05/25 16:36

ThousandKaw!

Thanks for helpful notes and offer of brain picking.

Cool, even has an expansion chamber on it!! Lot's of power.

Doesn't look tooooo bad. I've seen and resurected worse...

Yup, you'll be in for some chain and sprockets. Have fun there. It's kinda rare 525 chain. Chain's not too bad, you can get that from Dennis Kirk still, Go to the street bike catalog though, for some reason they don't sell it in the off road catalog.

Finding sprockets can be a little fun. For what it's worth, the front and rear sprockets off of the old F8 250 or the 350 Bighorn (F5 or F9) are the same. In case you go to one of my favorite places, a motorcycle salvage yard. The number of teeth will be different, but you can mess with the gearing that way to.

The Bighorn and bison are actually a little more common in those places than the F11's.

Post edited by: ThousandKaw, at: 2007/05/25 18:37

Got the carb cleaned up. Surprise find of jet in the bottom of the float bowl? What's with the piggyback main jets?

The start/diverter plunger was frozen. Got it freed up but the spring is rusted and weak and the cable is shot.

Replaced main oil line from tank. PITA getting new one threaded through case. Blow fishing line with air, pull string with fishing line, pull heavy Brit bike clutch cable with string, pull oil line with clutch cable Primed pump and done.

Exhaust and intake are reasonably clean.

Curious about points. There is a marker on the case and on the rotor. These line up at about TDC and the points start opening here. Is correct? She kicks back pretty good! Gap/dwell? Will she run right without a battery? I managed to run through about 1/2 a float bowl of fuel. I don't know if this runs premix or injects oil from that tank but put in 50:1 just to be safe until I find out. She was 4-stroking half the time. Let me know if I need to glom a 6V battery from somewhere.

Looks like a petcock, spring, cable, and maybe a battery and she'll be running enough to see if there os any power, once the next problem is solved.

The next problem is with going. She won't shift into any gear. I should have checked before parting with $ but just plain forgot. I could really use some tips here!

No. Does not go into gear rolling forward or back. Does not go into gear turning engine over. I can't feel any 'action' through the shift lever.

Working on something else today...

Post edited by: Duck, at: 2007/05/27 05:38

This bike looks a lot like mine. It's a 1974 Kawasaki KS125...

F11 seems to be incanabula akin to Z1 but motocross.

If anyone knows of an online FSM, I'm afraid it's time to consult one.

Not KZ but is is a Kaw and firt year of 250CC kaw motocross bikes(same year as Z1). 1973 F11

It felt like there was no action when moving the shift lever. Took the right side cover and clutch out and sure enough, the pawls engage the pins on the end of the change drum but impart no rotary movement. This is my first foray into a transmission so a little help is appreciated.

Looking at the diagrams on the buykawasaki.com web site it looks like I'll have to open up the case to see what's jamming the change drum. I'll need a copy of the FSM if I'm gonna dig this far. Heads up to a downloadable copy will be greatly appreciated.

Suggestions for diagnostic and fix are welcome.

-Duck