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Old 03-25-2012, 10:41 AM
msagnelli msagnelli is offline
Motorized Bicycle Newbie
Join Date: Mar 2012
Location: lansing, mi
Posts: 3
Default Re: help with grubee skyhawk gt5

Have change mixture to 32:1 and unit runs for 5 minutes and then dies.
Idle screw still has no effect. Not shure if it opens the slide.
Maybe the vaccuum leak is the O ring on the carb. I will look into it.
I assume it's the connection to the engine, or maybe the manifold connection.
Seems to run ok for awhile then dies. Choke still screwy.
What a nightmare. thanks for your help.
We will get this thing running!!!
thanks again.
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Old 03-25-2012, 10:58 AM
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Al.Fisherman Al.Fisherman is offline
Motorized Bicycle Elite Member
Join Date: Sep 2009
Location: Calera, Alabama
Posts: 1,966
Default Re: help with grubee skyhawk gt5

Runs for a few minutes and quits.....when it quits, do you have spark at the plug? Could be a crankshaft seal (1 or both). The carburetor to the intake hook up (O ring), or the intake manifold to cylinder gasket. To test for a leak if you can't find it either pull a vacuum (best) or put pressure in the case... about 5#. Block off intake and exhaust and use the plug hole. Piston at BDC. How are you set up for tools, if any?

If you have a CNS carburetor, get rid of it and get a NT, so much easier to work on.
Looking for HT's parts?
HT pre instillation tips.
Engine running problems?
HT breakdown Photos

Ron ><)))))*> Calera, Alabama

Last edited by Al.Fisherman; 03-25-2012 at 11:09 AM.
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Old 03-25-2012, 10:59 AM
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rustycase rustycase is offline
Gutter Rider
Join Date: May 2011
Location: Left coast
Posts: 2,745
Default Re: help with grubee skyhawk gt5

Do you have an idle speed adjustment screw AND and idle mixture adjustment screw?

If brand new, I wouldn't expect it to idle perfectly, and I would not let one idle for that long, Period! The clutch is not designed for that sort of use, IMO.
U might want a 2nd opinion on that part.

If the idle mixture screw is doing nothing, u probly got an intake leak.
CNS must be pressed firmly onto the intake spigot, as you tighten the clamp.
Over-tightening WILL break things!

Some RTV goop applied to the outside of the carb clamp could help A LOT!

and it's a chinagirl.
There could be a whole raft of other probs contributing to the poor idle!!!
bad gasket, warped manifold, pinholes in castings or welds, internal carb problems, just basic CNS performance!!! the possible probs are nearly endless. lol

But it sounds like u DO have it running...
I would run it around and worry abt the idle capability after getting some miles on it.
... more fun!

Best to read the carb adjustment threads already posted... tons of good info in them.
Welcome to the club!
My goal is cheap, reliable, personal transport, below the tax collector radar. Fun counts for a lot!
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