Hi guys, after a few minutes of ride my speedfight was unable to even move a wheel, i let it rest for ~5min's and he's alright again, but same shit happens after few minutes ... The problem was a main jet, after replacing the main jet to a smaller one everything was alright except the acceleration and top speeed ... Acceleration really sucks and top speed is around 50km/h (it was 75km/h before the main jet change). I can't understand how my main jet suddenly became too big ? I rided my scooter with this jet for months and everything was just alright, and maybe you guys have suggestions how to bring back my acceleration ? btw thanks in advance for your help P.s. mixture seems to be good now, spark plug has a chocolate color, btw same color was before changing that jet.
Yes main jet is too small so running lean,piston starts heating up causing is to not moving freely in the barrel due to heat and expansion of the piston and rings,clean the carb and change the jet back to what it was if it was larger .
Dude you don't understand if i put my bigger jet it's even can't move a wheel becouse mixture it's too rich, and spark plug is always wet. But the thing is how this one happened ? It was okay with bigger jet but suddenly out of nowhere it became too rich, that's why i put a smaller one. And now it's not running lean i checked spark plug color and it's ok. (Chocolate color)
Its going to be a process of elimination,have you adjusted the mixture screw,not the tickover screw,check your air filter and check the auto choke is not staying on full.I would say it most probably the last but it will be a case going through them step by step. What is the bike and has there been any modifications done such as sports exhaust or air filter,70cc kit
Bike is speedfight 2, there are doppler s3r sport's exhaust, malossi e5 air filter and malossi multivar. Choke has been changed recently, it works perfectly now. Idle mixture screw is adjusted well.
I'd check the piston for damage , you can set it up all you like now but if the barrel is scored it ain't going to improve if jetted correctly . Also check for air leaks by the crank seals , check the reed valves are good and clean the carb out properly with compressed air . And also , do you really need a open air filter ? It's hardly high performance and really doesn't need to breathe that much more . I'd stick with a standard air box , possibly slightly modified if needs really be .
