Hi , ive just bought my kids a yakuza 50cc quad . Got it of my mate at work . I remember when he bought it new about 3 years ago but his kids never used it , only a handfull of times . Any way im having trouble with it . It starts up brilliant but it will not run properly off choke. It has full revs on choke while its cold then when engine at temp i have to play with choke to keep it running . Off choke at engine hot temp all it does is miss fires chuggs and conks out all time . No power at all . Ive stripped and cleaned carb and replaced sparkplug . It seem slightly better as i can just make it rev , but still without choke its got no go what so ever . Can anyone help please

 

did you remove the jets and clean them separately when you cleaned the carb? sounds like a fuel delivery issue to me.

 

Yes jaster ive done that pal . I used an aerosol , i think it was AT 90 fast cleaning solution which is what i use when cleaning my 3.5cc nitro rc car . It brill at washing oils n dirt away . When i cleaned carb it almost looked as if there where oil deposits lingereing around the float chamber . Wondering if my pal has put two stroke oil in it . Also has a small inline filter . So i think next step is clean tank out and replace filter . When i asked my mate all he says is it was running good ?. Thanks for your input , as they say two heads are better than one

 

A big problem with these tiny jets is corrosion of the jet’s metal if they are left unused for more than a few months, I work on Tillers as well as quads (hence merryman) and one model had a fixed jet Dell’Orto carb. They were never any good as, used for a couple of hours then left for twelve months, the jets would corrode and they would only run on choke next time out. Cleaning out with air or carb cleaner was no use. The same engine on lawnmowers was not as bad because the lay up was shorter and, once running, the jets do clear themselves, but may need choke for an hour first time after winter.
Either run the quad as it is for a while or fit a new carb.

 

Thanks merryman . When i took the jets out they were a dull black colour , would that be a sign of corrosion . Also what you was saying about running it on choke . Everytime ive had a go at solving this problem ,it is getting better off choke . So running it on choke is my next job i think . Ive only had it running a half hour tops since ive had it .Again thanks n fingers crossed cuz mi kids cant wait to start riding it :-)