1982 G1 missing at WOT

[willie1981]

I have been rebuilding a 1982 G1 from the ground up for several months now and it is starting to come together finally. The engine has been rebuilt from top to bottom, bored .25 over, shaved the head 0.025, and purchased a stock air box. It seems to idle up and down constantly and misses bad at WOT. Any advice would be appreciated. Thanks..

[1970buick]

HI, seeing as you did a full rebuild, I assume you rebuilt/cleaned the carb. Mine was doing the same thing and there was something in the main jet restricting fuel at wot

[willie1981]

Yes, carb has been cleaned numerous times. Could the Jets need to be slightly larger from the boring and shaving of the head possibly? I pulled the plug and it appeared to be between a white and tan color.

[Cvans]

It is possible that your jetted too lean. Check your spark plug. It should be coffee colored. If it is lighter or egg shell colored your too lean and need to get the problem resolved before the engine is damaged or seizes up. If it is dark or wet your running too rich or the plug is miss firing. If the plug is coffee colored try a new plug.

[willie1981]

Thanks. The color does appear to be the color of an egg shell maybe slightly darker. I will get a pick of the plug in the a.m and get it posted. It seems to run smooth except at idle and WOT

[chompy]

My experiences with the "82" is that they have a tendency to not run very well at WOT, unlike all other G1 2 strokes. The 82 has a lower compression and odd porting in the cylinder designed really for going slow on the course. Think about changing the top end if you want more speed.

[willie1981]

That makes sense. I found a small air leak around the air box which fix the idle surging issue. Took the carburetor apart again and cleaned all of the jets. The engine idles and running so really smooth now except for wot. I am hearing get some noise in the top end. Is this normal for the 2-stroke? There was no slack in the rod or wrist pin bearings.

[Cvans]

It's possible that your timing is advance a little too far and your hearing pre-ignition.
This could also account for the rough running at full throttle.

[willie1981]

OK I will double check the timing. Just to verify, does turning the timing plate towards the front of the motor advance or retard the timing?

[Cvans]

I would have to look at the service manual to tell you. I installed a diesel in my cart some time ago and can't remember how the timing is set.