Modern Buddy

Hello!

I have a buddy 50 that a put a big bore kit in. The kit has been in for a year, recently it started hesitating when accelerating. Starts right up, idles great. I changed out the carburetor for a new one, it ran okay for a few minutes and then had the same issue. I changed out the fuel filter when I changed the carburetor, the fuel does not look dirty. Also my fuel gauge sometimes works sometimes does not all of a sudden, same with the mph gauge, could this be electrical, could the stator be bad?

Anyone have suggestions?

Does it clear up at higher Rpm? Check the charging voltage.

No, it studders all the way to top speed which is about 30mph right now, but the studdering is very even, and it comes back to idle without dying. Doesn't seem like a fuel issue. Do I just check voltage at the battery during idle?

Rule out worn or sticking transmission parts.

I was recently working on a 125 that did that. Turns out the spark plug gap was too big. I set it according to the manual and it cleared right up.

When I have it up on stands and give it full throttle you can hear it's sputtering at full speed, but doesn't seem to have much issue getting up to speed. I don't think it's transmission because of that.

Also it's the same spark plug I've had when it worked great before, it started slowly doing this and now it's all the time.. very lost at the moment, might try to change out the plug first, don't want to just throw money at it, hoping to diagnose some ways first

Thank you guys for the replies

Have you pulled the plug and looked at it recently? Just because it used to work doesn't mean it will always work. Burning oil with your gas does a number on the plug. You never tell how many miles the bike has. Buddy spark plug caps are crap, so are older Genuine Stators. You don't state the year or the miles. Lot of knowledgeable people on this site, but no mind readers as far as I know.