125 tri moto issue

[Motrike]

New to the site looks like alot of great knowledge from the people on here. I recently trade a guy for a 125 tri moto, ran fine no problems except when I would give it gas it would bog down sometimes until the throttle was wide open and then it would pick up and take off and when I would hit bumps it would bog down and then pick back up. Pulled the plug out looked really dirty replaced it with new One and it ran perfect. Now it's doing it again haven't pulled the plug back out to check yet, but it's also revving up will idling I will shake the bike and it will go back to idle and a couple of seconds go right back to revving. It's not a high rev but when I kick it into gear it will actually take off and go without me touching the gas, it will stay like this until I hit a bump and then it will go back down to normal idle for a sec then pick back up. Thinking of taking the carb off and cleaning it out but never have I attempted a mikuni, the oil is premixed for this motor the oil has been bypassed. The guy I got it from said he just installed a wiesco top end kit not to long ago. Any help would be great I just want to make sure I'm headed the right direction before I start thanks.

[Kit]

Pull the carb off sounds like the throttle valve or something is sticking. Take it all apart let it soak it in carb cleaner for a hour or more depending on how badly its gummed up put it back on and see what it does.

[old-yellow]

check throttle cable and where it runs to the cable splitter

[Motrike]

I'm going to take the carb apart this weekend I have been slammed at work. What am I looking for though on the throttle cable? I have a feeling that's what it is, just not sure what I'm looking for where it Ys.

[old-yellow]

the cable comes from thumb throttle then spits to the carburetor cable and to the oil injection cable, the splitter is right under the rear fender by the front seat latch.

[Motrike]

Ya I know where it splits at under the seat but it looks normal to me, like is there anything specific I should be looking for to see if it is messed up?

[old-yellow]

you have to check the splitter to see if it is binding the cables up, theirs 32 year old grease in there. Old-yellow

[just ben]

no brainer, the float and or the inlet valve is sticky a good cleaning(proper cleaning) should clear it up,maybe a new needle and seat (inlet valve)

[MTS]

sounds like a lean condition, check your fuelcap for venting your petcock for fuel flow make sure the oil inlet on the carb is capd off good and tight if its running on pre mix, free throttle cable movement if its still hooked to the oil pump it could be binding if the pump spring is full of crap or rusty,clean air filter, properly cleaned adjusted carb...start with the simple, let us know what happens, could be a few other things

[Motrike]

ok well i took the carb apart and cleaned it all out everything looks good except there was some pitting going on inside the carb, i checked the throttle cable out and tried shooting some grease down it and started it back up and reved higher than it did before. I called a local atv shop and he thinks i have a air leak. Not sure if i should try and figure this one out or let the pros do it. Any ideas on where the air leak would come from or does that sound like that could even be the problem?

[just ben]

if it is reving higher after having the carb apart my guess is something didn't go back together right.

[old-yellow]

try checking the slide is moving up and down properly in the carburetor, next try spraying starting fluid by the carburetor boot with it running to see if there's air leak it will rev higher if it is.

[Motrike]

The revving had gotten worse before I took the carb apart, I'm not sure if the motor could revv any higher. Is that boot the only place a air leak could take place?

[old-yellow]

the cylinder can leak at the base gasket and or at the head gasket or the crankshaft seals causing it to suck air and rev high. try doing a compression test and leak down test to see what there at it may help finding out whats wrong.

[TimSr]

Did you loosen the throttle cable adjustment so there is some slack in the throttle to make sure the cable isnt pulling?

Did you turn down the idle screw?