Any 2 stroke gurus?

[not2shabby]

and it runs fine for 15-20 minutes then starts cutting out and almost dies. Pulled the plug and it looks fine. Leave the bike sit and cool off and it fires up 1st kick and runs fine for another 15-20 minutes. I took the petcock off and cleaned it up, it wasn't too bad, but was hard to turn. It only has 2475 miles on it and looks practically new. Any ideas?

 

[FarWestFastEddie]

Has been sitting a long time? is the choke sticking? If the plugs are not fouled, are the dry? may be lean fuel mix..

FWFE

 

[Geezer]

Is it oil injected or do you mix oil with the fuel?

Since it runs OK until it gets hot, and the plug stays clean, I suspect not enough oil in the mix.

If it is oil injected then the injector may be clogged.

 

[not2shabby]

Yeah it's oil injected. How can you tell if the pump is working? Oh, it smoked a lot riding it home so I kinda doubt it's not getting oil. It doesn't smoke nearly as much now. It has been sitting a long time.

 

[not2shabby]

Still has the original tires....yikes!

https://i1194.photobucket.com/albums/aa370/not2shabby/1120506077_photobucket_123258_.jpg

 

[racer]

Check the coil.

 

[Geezer]

Yeah it's oil injected. How can you tell if the pump is working? Oh, it smoked a lot riding it home so I kinda doubt it's not getting oil. It doesn't smoke nearly as much now. It has been sitting a long time.

lol, yes a 2 stroke can sometimes lay down a nice fog of smoke. If the oil was not pumping at all you would get clean exhaust and I doubt the engine would run for 20 minutes.

After the engine quits can you turn the engine over? I'm guessing it has a kick start. If it does then you should feel more resistance when hot if it is an oil related issue.

Have you drained the old oil and put fresh stuff in?

 

[not2shabby]

The PO said he just had it tuned up and oil changed, but I might change it anyway. I've started it up a few times after riding it for a while and it doesn't seem any harder to kick over when warmed up. How do you check the coil?

 

[joebiodiesel]

Yeah it's oil injected. How can you tell if the pump is working? Oh, it smoked a lot riding it home so I kinda doubt it's not getting oil. It doesn't smoke nearly as much now. It has been sitting a long time.

Anytime I fire up an injected 2 stroke that is new to me, I add some oil to the tank as premix for insurance. Once you see that the oil in the tank is going down it is safe to stop using premix. I like the Amsoil 100:1 for this.

Joe

 

[motodave]

If it was seizing then each start up after a shut down would run less and less and while hot wont turn over at all. I suspect coil... plug cap or even points and condensor. just check for spark when it shuts down= no spark check all of the above for cause..... next when it dies turn the fuel petcock off imediatly and drain the carb if dry or near dry you have a float issue (amazing how long a float bowl of fuel will last)

I love the two strokes so simple yet so fun to keep working..... also the wrong injector oil will cause all sorts of havoc, I know I ran some cheap two stroke oil in my jet ski once and for the life of me I couldnt figure out why it ran so bad until I drained the oil and started over.

 

[escapefjrtist]

I'd be looking for an electrical sort of problem. Take a pic of the spark plug and post it up to give us some more clues.

If you're concerned with the oil injection system and IIRC from 35+ years ago, there are timing marks on the oil pump cable pulley. Adjust the oil pump cable so the mark lines up when the slide just begins to lift.

Lots of info via Google, here's a thread on ADVRider.

I grew up on those old Kawasaki's. Have fun with it!

--G

Edit -- Just read the whole ADV thread...not too far off.

 

[mcatrophy]

... Any ideas?

Tank breather clogged?

 

[not2shabby]

Ok, I did check the pump alignment, all good there. It's running honda 2-stroke oil, he gave me a quart he had left. Now the carb is leaking out the bottom of the cover. I'm suspecting either the floats are filling up with gas or the float valve isn't shutting off the flow, but not sure why it's ok after cooling down. I read on another forum (can't remember which one now!) that Kawi 2-strokes were prone to getting crank seal leaks. This kinda makes sense; when it gets hot they'd start leaking air and then when they cool down, they'd seal again. I rode it for 20 minutes or so yesterday and it didn't act up, but I was just puttin' around the hood. Both times it did act up was after running 50mph for a while. It never actually died, just lost power and would sputter and backfire if I tried to give it any throttle. I'm gonna order a carb rebuild kit and tires today...32 year old rubber isn't exactly confidence inspiring! I'll pull the plug tonight and post a pick. Is there a way to test the coil? The PO said he just had it tuned up, not sure if that meant new points and everything.

It is fun to buzz around on the little beast, makes me feel like a kid again even though I never had a 2-stroke. Thanks guys!

 

[not2shabby]

... Any ideas?

Tank breather clogged?

Nope, checked that too, and it's got a brand new air filter.

 

[timk]

A good ohmmeter can test the coil,after getting the tolerences. Early RD coils were marginal so I hung two Chrysler car coils using a balast resister with. Correct heat range on sparkplug sometimes helps. I wonder if the service the owner had done included de-coking thhe piston/head? That's a regular part of 2-stroke maintenance. If the exhaust has a removable baffle, you decoke it also. If there's too much coke on the piston,it wll glow red,causing misfiring. I would double ck the point settings. Once you get it sorted ou,it'll put a grin on your face. I still keep a 2 stroke around when I want to relive my youth.

 

[not2shabby]

A good ohmmeter can test the coil,after getting the tolerences. Early RD coils were marginal so I hung two Chrysler car coils using a balast resister with. Correct heat range on sparkplug sometimes helps. I wonder if the service the owner had done included de-coking thhe piston/head? That's a regular part of 2-stroke maintenance. If the exhaust has a removable baffle, you decoke it also. If there's too much coke on the piston,it wll glow red,causing misfiring. I would double ck the point settings. Once you get it sorted ou,it'll put a grin on your face. I still keep a 2 stroke around when I want to relive my youth.

I did read somwhere about decarbonizing the exhaust, but not anything about how to do it. With only 2500 miles, should it need this done? Wouldn't that affect it cold or hot? I do remember the PO saying he's running a hotter plug...a 7 instead of an 8 IIRC. Maybe I should get the stock plug.

 

[not2shabby]

Holy crap! Bike Bandit wants $67 for the float and $48 for the float valve assy!! But, you can get a whole new carb for $96. Dayum! Maybe I'll check around a little more...

 

[not2shabby]

Here's the plug...I pulled it today after running around the yard with the petcock shut off to drain the bowl. I want to tear the carb down and clean it because I think the float valve is sticking. It's been leaving a small puddle on the garage floor. I'm wondering if this isn't causing the bogging problem too.

 

[escapefjrtist]

Plug looks pretty darn good.

Continue eliminating the easy stuff, sounds like you might be on to something with the carb. I do remember my 175 leaked a little fuel once in awhile...

--G