I could use some help figuring out the many problems I am having with a 110cc chinese quad that I got from my sister. It started with no spark. I checked all my wiring. It all seemed to be good. I checked the stator and pickup and everything seemed to be in good working order. I checked all my kill switches and these all seemed to be in good working order. I have another chinese dirt bike that had the same cdi unit on it. I switched these out and now I have spark. The funny thing is the cdi that I took off the quad now works on the bike. The spark issue must have been fixed by something else i did. So now I have spark but cannot get the the engine to run unless the choke is on. I have cleaned the carb 3 times. All the passage ways seem to be clean. The first time I cleaned the carb I found that the idle jet was clogged. I could not find anything small enough to pass through the jet but I cleaned it with carb cleaner and now I can see light through it. This still did not fix my problem. The quad will only run with the choke on and the idle adjust screw adjusted all the way in. So I decide to purchase a replacement carb off of E-bay. I installed this carb and it seemed to slightly cure the idle issue. The new carb will allow the bike to run without choke but it still has to be at a high idle to keep the engine running. The engine also seems to be running extremely hot. Any suggestions?????

 

It may not be jetted correctly. Also have you by chance checked the valve clearances? Some of these have poor airfilters and if you suck too much dirt in it can wear the valves.

 

I do not know what the proper jets would be. The replacement carb was a cheap aftermarket one that says it fits most 50-70-90-110cc chinese bikes. What would the correct clearance be on the valves?? Another question I have is would a bad cdi or coil cause delayed spark??

 

Welcome to the forum DHirschy!

Have you adjusted the fuel screw at all? Id start with it 2.5 turns out..

Valves should be set at .004 with the engine stone cold..

From my experience CDI's and coils work, or dont work, unless there is a bad wire or ground.

 

Just bought one for my daughter. I've had starting idling issues right off the bat with my 110. It's a nice machine but has a hard time starting and idling. Should i take off the air filter and spray some carb cleaner in there? i can't find a set screw with a spring on it to play with the idle. All i see is the flat head screw with some blue paint on it. Am i missing something? Any help would be appreciated. Thanks!

 

I would take the carb off and clean thoroughly. There should be some kind of idle adjustment on the carb. What I finally did to take care of my problem was order a new carb and it ran fine. The boot that goes around the throttle cable on the top of the carb had a few splits in it and I believe that it was sucking too much air and that is why I couldn't get mine to run unless it was choked.

Carb I purchased was a PZ20 and it only cost 15.99 plus 10.00 S+H off Ebay.

 

I found that carb on ebay too, $15.99 + $10 shipping, from Texas.

The sellers description says it has a petcock, is that true?

 

I had the same problem with one I got this weekend. I finally just messed with the screw you mentioned. If you turn it clock wise all the way, then back it off 1/2-3/4 turn, it should start and stay idling. Then I backed the screw off until it sounded good. After a few minutes, I had to back it off a bit more, as idle speed gradually got faster. It took a few adjustments, then ran fine. When it cools down, I have to do it all over again. I don't know if it's a good idea or not, but it works for me and no one has told me not to do that yet, or given me any better advice. I'm sure there's a bigger issue, but I've had neither the time nor the smarts to do anything about it yet, and 8-year-olds don't have much patience.

 

The sellers description says it has a fuel petcock but it actually does not. Some of the newer carbs that I have seen on ebay come with a built in petcock on the side of the carb but this one doesn't.

 

I apologize, I probably shouldn't have posted here, as I am far from an expert. Disregard my advice until you hear from someone who is an expert.