1984 yamaha trimoto 125 Questions

[adam]

i have a 1984 yamaha trimoto 125 and i get it running and it idles good then the revs get higher and they stay why does it do this?

[adam]

any one have an idea of what it might be

[Vealmonkey]

on my 125, when it revs high it usually means the carb boot isn't secure around my carb, but I doubt that is your problem. I would look into a fuel starvation issue, or some kind of issue affecting your fuel flow, maybe the screen for the fuel valve or a pinched fuel line or a clogged vent on your fuel tank or maybe a clogged fuel cap.

[adam]

ok how do i check for a clogged fuel cap? and i was running it with no air cleaner lid just idling it and it didnt seem to rev up like it did before

[Vealmonkey]

Well, The fuel cap should have a piece in the middle of it that a vent hose attaches to, you should just be able to run a pipe cleaner through it. When I first got my 125, it didn't run right without any aircleaner on it. Maybe make sure your air filter is good and clean and oiled and try reinstalling the lid and make idle adjustments then or if you can get it idling ok without the lid, get it idling as best as you can and try installing the lid and readjusting the idle. Mine idled better with some restriction on it, when it had too much air, no air cleaner or lid, mine idled way high.