Yamaha G1 Only Runs with full choke and full Throttle

[worqhors]

Originally Posted by texastom1

I finally got my own compression tester and found that I only had a compression reading of 60. I think I read that it should be around 100 so I went ahead and ordered new rings for it. I went ahead and ordered a new spark plug and filter as well. I figured it couldn't hurt.

I did want to ask can low compression make it only run with full choke? I know a 4 stroke will run weak but I'm not real experienced with 2 stroke motors. Also has anyone has had a crank seal that looked good but still leaked? Everything I read here on the forum says crank seals is the major issue but when I took the clutch off and the oil pump gear, the seal looked like new...Can it still be leaking? Should I go ahead and replace both side gaskets for the crank or wait and see how the new rings do?

Thank ya'll for all of the help..Ya'll have been such a blessing with your help and advice.
Thanks,
Tom

If that G1 is a 1982 model, it will run at 60 psi.

[texastom1]

It is a 1983 model 215cc It's a J24

I have heard that the 1982 model had a lower compression for so EPA thing. I'm glad this one is a 1983 so it has the stronger motor.

Thanks though for your information.

[cgtech]

Check your compression (130 psi normal, except 1 year low compression model). plug the carb and exhaust pipe, blow smoke into the fuel pump pulse line or spark plug hole. you are going to be looking for any smoke leaks at the crank seal by the clutch and crank seal area where the cooling air inlet. if you are driving it around with bad crank seals, you are hurting it right now!!!

[worqhors]

Originally Posted by texastom1

It is a 1983 model 215cc It's a J24

I have heard that the 1982 model had a lower compression for so EPA thing. I'm glad this one is a 1983 so it has the stronger motor.

Thanks though for your information.

Yes, the J17 or 1982 model has a lower compression. That's the one I have, unfortunately. It runs even at 60 psi.

[85.G3]

Tom .... Mine has a factory timing mark, you can see it top left in the first photo and bottom right in the second photo. Mine has the arrow on the plate perfectly centered between the 2 pins on the case. Make note before you unscrew the plate. Any advance here would help forward and hurt reverse or vice versa. I have read here that there is an advance in the ignition that is different based on the key position forward or reverse but I can't confirm. A small 2 or three way puller hooked in the mag cover slots will get it off. I had to buy a primary clutch puller from Plowmans, order it with your parts to save time and freight, I think it was $32.00

[texastom1]

Thank you so much Mr. 85.G3 and all the rest of you. Ya'll all have been a freat help. I can't wait for my parts to come in so I can get this cart cruzin.

So if I am correct I should make sure the timing is put back to the same spot as it was because if I move it one way or the other I might mess with the way it runs in either forward or reverse, Is that correct? I guess you really don't time these 2 strokes. They must be very forgiving motors.

[worqhors]

Well, I have mine a little "advanced". It's a matter of preference.

[cgtech]

may be too late for you, but, i always punch-mark the plate and block so its easy to put back where it originnaly was.

[texastom1]

No you are not too late cgtech I am still waiting for parts to come in. That sounds like an outstanding idea. I had planned to use a magic marker, but I was worried that it might get washed off in the cleaning. I tend to be a little OCD about cleaning when I am doing a repair. I can't help myself I just can't take something apart and fix it then put it back together without really getting it clean and I mean new clean. I know there are those that can just fix it and leave the dirt but I am not one of them. I have been really cleaning this cart while I wait on the new parts to get here.
All this to say the stamp idea is a good idea ...
Thanks,
Tom

[texastom1]

Well I am very happy to say that the parts came in for my cart yesterday. I spent the day getting everything back together and this baby purrs like a kitten. It runs smooth and strong.

Thanks everybody for all of your great help.

Now I can go ahead with my plans to put a lift on it and off road tires. I plan to use this baby to run around the back 40.

Thanks again All,