I have a 14′ with muzzy exhaust/ intake… my sons been driving it for the past two months with zero issues.
Yestersay mid driving it started to get a real bad sputter, only happening at full throttle, today I removed the carb and thoroughly cleaned it, replaced the plug ( which looked to be fouled ).
I replaced the plug and put everything back together, she is still sputtering at full throttle, I can hold it about 3/4 throttle and it’s fine.. the last 1/4 is where the issue is.
During the carb clean I was going to move the needle clip up one to lean it out but found it was already at the top adjustment. The jetting is 135/40 and the carb is a Keihin. I didn’t think these came stock with keihin carbs but it looks identical to the factory carbs I found online.
I also checked the small white fuel filter which was clear of debris.
Could it be a bad pump? Jetting change? But it was running fine with current jetting.. we are at sea level.
I put the new fuel pump on it, did not make a difference… so I removed the carb again and installed a 140 jet… so 40/140.. put everything back together… still has a sputter.. wtf! Pulled the plug after a few floored runs around the block.. looked great. Removed the bowl again and tried a 38 jet.. so 38/140 now… took her back out.. same crap. So frustrating…
Starting to thing it’s something electrical? Maybe something got wet?
Any advice would be greatly appreciated.