Jump to content
Sign in to follow this  

thumpstar/pit bikes with throttle problems

Recommended Posts

been out on the bike today for a good 4 hours...... the bike started fine for about 30mins, then it started to bog down when the throttle was opened, took the bike home checked the bike over, nothing i could see was wrong, started it up again, still bogging down, check and unplugged the spark plug, and it seem to be fine....... carried on riding most of the day, for another 3 hours or so, then it started again, but this time it would come and go, I'm was using 3rd gear mostly, when the throttle was open it, it would very bog down then all off a sudden the power came back........ after that it was geeting dark, on the way home the bike seem fine..... has anyone had this problem.

Share this post


Link to post
Share on other sites

well is ur filter dirty? when i went to the track my filter got really dirty and i noticed some dirt went into the carb...befor i noticed this my bike would bog down just like u said...clean ur carb out with brake cleaner its acually much better than carb cleaner cuz it doesnt leave any oily residue

Share this post


Link to post
Share on other sites

Clean out your carby, and check for air leaks around the carby/manifold gaskets.

Share this post


Link to post
Share on other sites

I'm with you on this one! Gotta be a dirty filter.

Share this post


Link to post
Share on other sites
well is ur filter dirty? when i went to the track my filter got really dirty and i noticed some dirt went into the carb...befor i noticed this my bike would bog down just like u said...clean ur carb out with brake cleaner its acually much better than carb cleaner cuz it doesnt leave any oily residue

I use brake cleaner too, but be careful not to get it on gaskets and seals in the carby, particularly 'O' rings. Certain brands of brake cleaner can swell rubber. Carby cleaner likewise.

Share this post


Link to post
Share on other sites

Intermittent problems like this might either be a dirt in the carb or electrical. I helped a guy diagnose an XR-70 with similar problems and it turned out to be the wiring going to his kill button. You might check that!!

Share this post


Link to post
Share on other sites

If it is en early Thumpstar, have u checked the carb bowl is not resting on the fins of your engine. If it is, it could be either heating up the fuel in the bowl, or even frothing up the fuel inside, because of the vibrations, so it misfires!

Let me know how you get on!

Share this post


Link to post
Share on other sites

have a look at the spark plug,if its realy sooty,it could be that it is running rich,dont change any settings on your carb,it will be a bad earth,not letting the plug spark proply,check the wires on th condenser,also when you start it see if you get black smoke out the exhaust,this is also a sign that its to rich

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...