Hensim 110cc
rebuilt carb and has new spark plug.
will start up but busts up while running like it misfiring.
cant get the ilde down,the idle screw has no effect on it.no leaks and everything is nice and tight,
everything has been gone thru,rebuilt or replaced.
never had one of these I couldn't get to run correctly.
and to make sure it wasn't the carb,i have swapped out 3 different ones and it still does it everytime.
any suggestions would be appreciated.

 

By "idle screw" I hope you have been adjusting the throttle stop and not the slow running mixture screw as this is a last resort and everything else has to be right before touching it. If you have been adjusting the throttle stop without success, either the cable is too short or the slide or butterfly is sticking, because they should prevent any fuel/air mix getting into the engine when the stop is wound out.

 

Maybe check the valves?

 

throttle stop..idle screw..same thing.and it makes no difference.Only one I have ever had that did this.
Cable isn't to short,it is the one that came on it and this atv is pretty nice and I doubt anyone has ever tinkered with it before. But I can swap carbs and cables and I am getting the same issues.I have swapped at least 3 so far.
when the carb was rebuild,I counted the turns on the slow screw to make sure I put it back in properly.
this one has me a tad perplexed esp sinc ei have one sitting here that looks like death but is running like a new one..lol

 

ok,took it all back apart. re-cleaned it all. put it all back and at least now the idle screw responds . the slow screw has no response though and it will idle but sound slike it has a racing cam installed. u can rev it and it sounds n runs fine just sounds like it missing while idling
here is what has been done.
rebuilt carb
new spark plug
changed out cdi n rectifier with new ones for the giggles.


this one is 2 years old and owner said it has 3 hour run time when put away 18 months ago.

 

Symptoms are a clogged pilot jet or pilot jet circuit..

Weird.. Let us know if you figure it out..

does turning the fuel crew out 1 turn (more) help at all?

 

not clogged.esp as many times as i have had that carb out and rebuilding it with new jets etc.lol
the slow screw does nothing to it.idle screw does what it is supposed to though

 

I believe you.. also know how frustrating these things are at times.. its just what the symptoms would normally be..

Have you checked compression or the valve clearances?

Do you have another quad to try this carb on?

 

fixed the little sob.
the rebuild kit that came must have had the wrong jet in it because I took it out and layed it beside the old one....it was a tad longer. so I drilled the old one out,put it all back together and BAM...perfect!!!