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Help with a GY6 Please.

Posted: Thu May 09, 2013 10:20 pm
by 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?

Re: Help please.

Posted: Fri May 10, 2013 12:03 am
by bfowler
Perhaps the idle and air/fuel mixture screw isn't adjusted correctly. Could be the reason why your scooter won't idle correctly

Re: Help please.

Posted: Fri May 10, 2013 7:35 am
by Okil69
I could not, for the life of me, find a mixture screw.

Re: Help please.

Posted: Fri May 10, 2013 5:10 pm
by nhaven
Okil69 wrote: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

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 2:35 pm
by 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.

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 4:26 pm
by 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.

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 5:20 pm
by 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.

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 6:44 pm
by eliteguy50
LoveMyHonda wrote: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.

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 7:09 pm
by 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!!!

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 7:24 pm
by eliteguy50
That T lines up on the compression and exhaust stroke.

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 7:42 pm
by 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?

Re: Help with a GY6 Please.

Posted: Sat May 11, 2013 11:18 pm
by Okil69
The way I had it I had where neither side was compressed and I was adjusting them

Re: Help with a GY6 Please.

Posted: Sun May 12, 2013 1:24 am
by 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.

Re: Help with a GY6 Please.

Posted: Sun May 12, 2013 2:54 am
by Okil69
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

Re: Help with a GY6 Please.

Posted: Sun May 12, 2013 5:38 am
by eliteguy50
Okil69 wrote: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.