QuestionQUESTION: Hello, the bike is a Gilera RC50cc 2Stroke the problem is when revs reach 5 to 6k rpm, the engine hesitates or holds back for several seconds then revs out freely again which makes it quite difficult to ride, I have replaced the plug, the carb has been taken apart and cleaned the inline fuel filter is clear,the bike starts up well.
Have you any ideas what maybe causing this problem and how I can resolve the issue.
Thank you in advance..Al.
ANSWER: Hi Al,
I suspect the carburetor needs tuned to correct the air-fuel mixture in the mid-range.
It's possible that the carb was not thoroughly cleaned and/or the fuel system upstream of the carb was not cleaned and has re-contaminated the clean carb.
Respectfully,
Mark Shively
---------- FOLLOW-UP ----------
QUESTION: Hello Mark, thankyou for your reply, the carb has been taken apart and cleaned once by a bike mechanic in February this year and twice by myself,(it was very clean)the tank was drained too, the inline filter is clean & clear.
I've set the mixture screw at 2 to 2.5 turns out which seems to be the norm, and tried the screw in a little more and out a little more with no success.
Any further ideas please.
Thanks Al...
AnswerYou or someone will have to tune the carburetor.
I cannot be more specific without being there and performing a few checks and making a few adjustments.
Describe the appearance of the spark plug.
Check the condition of the air filter. Clean or replace accordingly.
Check for air intake obstructions.
Check for pinched or collapsed vacuum and fuel hoses.
Check the reed valves (if applicable) for defects and proper seal.
Reply to my email addy: yamtz750@gmail.com
Mark
