Help with a GY6 Please.

[Okil69]

Okay, I know this isn't where this post should be, but I figured you guys would look here first. I have an off brand gy6.
For starters, I bought a 100cc big bore kit with a new coil, cdi and upped the idle jet to 38, and the main to 110. I tried starting the bike, nothing. so I did a little Youtubing.. I had not adjusted the valves to the correct spacing. so I adjusted the intake valve as close to .003 as I could, and the exhaust valve as close to .004 as I could. Boom, fires up. But I have to stay on the throttle or it dies. Any suggestions/ideas?

[bfowler]

Perhaps the idle and air/fuel mixture screw isn't adjusted correctly. Could be the reason why your scooter won't idle correctly

[Okil69]

I could not, for the life of me, find a mixture screw.

[nhaven]

I could not, for the life of me, find a mixture screw.

There is probably a cap on it.

http://49ccscoot.proboards.com/thread/5 ... xture-scre

[Wheelman-111]

Greetings:

The cap idea on an emission-controlled CV carb is probably correct. The solution is to locate it. Carefull drill a 1/8" hole in its center. If you break through and hit the screw head, it's hard to fix.
Then thread a sheet metal screw into the hole, and wiggle the whole thing out to reveal the idle mix screw.

[Okil69]

I've actually hit another bump here.. I think the screws that you use to adjust the valves are too short? I try to set the valves and the nut that you use to keep the screw from coming out of its position won't go on. There's not enough thread for the nut to grab onto.

[LMH]

Are you doing it at top dead center on the crank and the cam? if you can bottom it out it sounds like its not on the compression stroke.

[eliteguy50]

Are you doing it at top dead center on the crank and the cam? if you can bottom it out it sounds like its not on the compression stroke.

X2, needs to be the compression stroke. Valves have an acceptable range( usually 2 to 4 thousands), no need to argue on one spec.

[Okil69]

Heres how I kept adjusting them. I had the flywheel at the T. and the two little holes lined up. then I would adjust the intake to .06 and the exhaust to .08 and I was never able to get the dang nut on.. I'll try your guys' tip when I get back home tomorrow. Thanks a bunch!!!

[eliteguy50]

That T lines up on the compression and exhaust stroke.

[Okil69]

So what you're saying is that I need to turn it a little more to compress one of the sides, then adjust the screw opposite of that to the specific spacing, and vice versa?

[Okil69]

The way I had it I had where neither side was compressed and I was adjusting them

[LMH]

Theres 3 holes on the cam, if you see all 3 your on compression stroke. 1 straight up and 2 lateral to each other.

[Okil69]

Yes like this
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Rough sketch. Lmao. But the way I was told on a youtube video was to turn the flywheel until one of the valves was pushed open and then adjust the opposite side to the right spacing, then turn it more till the ither valve was pushed open and adjust it

[eliteguy50]

Yes like this
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o |
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Rough sketch. Lmao. But the way I was told on a youtube video was to turn the flywheel until one of the valves was pushed open and then adjust the opposite side to the right spacing, then turn it more till the ither valve was pushed open and adjust it

The problem with that method is it doesn't account for valve overlap. There are times when both valves are at least partially open. At TDC of the compression stroke, both valves should be completely closed, guaranteed.