Won't idle with clutch in, help

Jasper · #1 07-22-2009, 05:07 PM

I just got my 80cc china kit from powerking shop on ebay about a month ago and everything was working fine until randomly after I stopped at the bank and went to start it up again it had lots of trouble and sounded as if the kill switch was on as I tried to get it going, and if I turn the throttle,it makes some noise but it goes nowhere and I need to keep peddling to keep the motor running. The weird part is that if i peddle and get going fast enough, it will start running normally and I can ride it, only until I pull the clutch in or slow down, then it dies immediately. I then put the idle screw almost all the way in and it will now idle with the clutch in AFTER it has been peddled up to speed and sounds normal again. and if i shut it off and start it up again, same problem need to peddle it up to speed. I recently switched to a 25:1 from the 16:1 break in i dono if that makes a difference

I have searched through the forum but I have no Idea what the problem is. I have checked:

Spark plug color and gap
Took cylinder head off and checked cylinder walls, looks clean
took the carburetor apart and checked for stuff clogging up in there
checked fuel line, fuel is running smoothly

I am all out of Ideas can anyone help?

**Dave31** · #2 07-22-2009, 05:54 PM

Welcome to the best Motorized Bicycle forum on the net!

You say you checked the plug? Have you tried to swap it out with another one? I have had several that have acted the very same way and every time it was a fouled spark plug.

**2door** · #3 07-22-2009, 06:07 PM

Jasper,
Yes, replace the plug but check to see if you're getting a spark too. I'm a little confused by your description of what is happening. It almost sounds, to me, like the engine isn't running at all but just being rotated by your peddaling. When you say it starts, do you mean it will pull your weight on level ground, or are you just hearing the engine being turned over by the momentum of the bike with the clutch engaged? Help us out a little and we can offer more info. You need spark, fuel and air for the engine to run. Sounds like you have proven 2 of those. Get back to us after you've confirmed that the ignition is firing. If you need help with that please ask, we're here.
Tom

**Dave31** · #4 07-22-2009, 06:14 PM

Check your wires as well, they could be loosing contact.

unior · #5 07-23-2009, 11:58 AM

try replacing the intake manifold gasket or using rtv to reseal it

Venice Motor Bikes · #6 07-23-2009, 01:22 PM

I concur!! Check all wires, plug & wire, check for intake air leaks... & also, check the head bolts for torque, see if there's any oil spitting out from the gaskets???

Jasper · #7 07-23-2009, 04:20 PM

wow thanks for all the input guys.

when I first try to start it up and I give it some gas, it makes a bogging out sound and doesn't accelerate at all. and now that you mention it its probably the spark plug, because the wires and connections seem fine, ill get a new one in the next couple days and let you all know

thanks again!

Jasper · #8 07-25-2009, 07:42 PM

I changed the spark plug to and ngk one and also set the gap from 0.38 to 0.22. I checked the head bolts for torque but there is still a little bit of oil spilling out of the head gasket but not a significant amount at all. is that bad if so how do i seal it? I also replaced the intake gasket and sealed it. It is running good now except it still won't idle, clutch goes in at any point and the engine dies. Any ideas?

Maxvision · #9 07-25-2009, 08:16 PM

Didja try tightening up your clutch cable?

Perhaps the set screw on the end of your cable wasnt tightened enough and the cable was slowly pulling out. I know on my engine I have to pull that clutch cable REAL tight before you tighten the set screw on the end of the cable and make sure the set screw is REAL tight too. The stock clutch lever on the handle bars barely have enough travel in them to fully disengage the clutch.

Sydneysider · #10 07-26-2009, 08:18 AM

I had exactly the same problem once with the engine struggling to accelerate and dying at idle.. at high speeds after pedalling my **s off the engine ran good. After checking and replacing almost everything, the engine was still struggling and I was at my wits end! The very last thing I did was remove muffler and found it was really blocked up with carbon. Im guessing at high rpms exhaust pressure was high enough and could escape more easily out. The black stuff tends to build up in the muffler more during run in with high oil/gas mixtures and low rpms so it needs a good cleaning now and then especially if its ridden at low speeds alot.. if you ride it fast enough exhaust gases will be hot to burn some of the garbage out possibly eliminating the need for cleaning it in the future.. check the muffler for easy air flow as it can really affect the performance of the bike.

Hope this helps..