Recently got a 1988 TRX 125 with original tires (in good shape but set around for a year). Has run great for the first few rides but began stalling whenever my wife stopped. In the field, I attempted to adjust the idle screw with no reaction. The ATV also was over revving after touching the throttle. The only way I could stop this was by choking it. This would return it to the idle state. Later I adjusted the throttle cable as it did have too much play. It does not appear to be sticking (as that is how it is acting). Pulled the fuel petcock screen, nothing there. Sprayed WD-40 around while at idle with no increase in RPM. Before I remove the throttle cable and needle from the top of carb I need to know what I'm getting into. The mixture screw has no affect on the idleing of this machine either. The idle screw is doing a little something now but we can't go riding like this. Thanks....Jeff

 

Are you sure you were adjusting the idle screw and not the air/fuel mixture screw? Revving like that at idle sound like an air/ fuel adjustment issue.

 

take your carb off and clean it. it dosn't take much grime to mess a carb up and being almost twenty years old, well.

 

Thanks Mack and Ribeye. Yes I'm sure it was the idle screw (philips with a spring) mixtures are flat head to the lower left with no spring right?. Anyway, I've been trying to avoid the inevidiable and was hoping for a dummy fix that I was not thinking of. But you are just one more person to tell me the same thing. I guess I'll be tearing a carb down. I'll let you know how it goes............................... Thanks again!

 

check the vacuum lines on the engine and the seal from the carb to the intake, also check the intake boot for any cuts. It sounds almost excactly like an air leak condition to me.

 

Would spraying WD-40 around these areas while at a regular idle looking for an RPM increase give an indication of what you are suggesting or is eather the only thing that will work for this (I did not have any starting fluid)? It only revs uncontrollably after I touch the thumb throttle. The intake boot looks good, but I could not locate any vacuum lines??? I see a black drain line off the bottom of the carb, and a top carb overflow/flood line and that's about it...?...

 

wd 40 will work for what you are trying to do.I don't think that you have any vacuum lines on that. you also might want to try to lube the throttle cable. good luck

 

Yeah, I was trying to determine the best way to do that and gave up (ran out of "play with four wheelers" time!). I'm still surprised out of the 4 ATVs we have, the HONDA would be the one to let us down. This thing is like a littl tank! thanks.

 

Thought I would follow with the fix here to benefit any others with similar issues: tore carb down and cleaned-no better - tore down and cleaned again - looked through low/idle jet and determined something is in it - tried everything possible to remove (carb cleaner, air, wire, drill bit etc.) Bought a new one and problem solved!