Poor idle, cheap carb, or worn engine, or???
 

Well my $17 china carb does run the 100. The engine does smoke from worn rings. I cant seem to get it to idle down reliably though no matter what I do with low speed jet screw. If I get it idling, after a minute it peters right out

It starts right up with no problems (with half throttle and choke).

Not sure if these carbs are known for these issues, or, what else it could be with these idle difficulties...

:bash2:


any advice appreciated! :)

My Chaiiii-naaw carb idles my 107 just fine :bigthink:

Perhaps there's some sort of casting material stuck in the idle circuit?
I can't think of anything else if it's a brand new carb.

My Original won't idle without partial choke, but it's got the original carb still. I just gotta get around to cleaning the fuel system up.

I have a china carb on my 108 and I've never been impressed by it. It idles like crap and it's not consistent at wot. I'm planning to go to my buddies house one of these days and buy a bucket full of used carbs and just rebuild them or use them for parts as needed.

I got one just for the hell of it. The fuel shup off needle jet has different threads than the OEM carbs.

Do you have the idle stop screw adjusted properly?

That was one of the adjustments that I worked with in addition to the idle mixture... nothing seemed to make it happy for any thing longer than about a minute

Did you replace the carb just for the heck of it
or was there a problem before you replaced the carb.
Maybe the problem wasn't with the carb.

I've used about a half dozen Chingchong carbs and
the only problem I ever had was some dirt in the float
needle seat and I don't think it was the carb's fault.

I bought the tractor recently and the carb was a lump of unsalvageable rust. The china carb was cheap and I though too simple technology for even them to screw it up. It could be just adjustment, as u said debris, or whatever. But i wanted to throw it out here in case these are all problem carbs or what... sounds like so far, the consensus is that they are not necessarily bad ...

I'll take it off and blow out the passages etc...

Do some carb swapping with something that runs right and you'll have your answer.

just tossing it out there..
burns oil.... bein rings are toast. maybe heat and head warps . lose compression.
piston is out of round so on ..
fouled plug
cruded up valve seats.

pop the head its easy enough to do..

cornfused. i see 2nd post now.. so is it idling ???? after you did the head ?

Sometimes people think when engine "peters out" at idle, they think they need to richen the fuel flow at idle. It may be the wrong thing to do since engine may be loading up with fuel and it stalls. Try the opposite... Go leaner. Looking at the spark plugs tells the tale but that's hard to do if you have a bad smoker.