I have an '86 trx 125. It was running really good a couple of weeks ago. When I got it it was a mess, so I cleaned it up, rebuilt the carb, and replaced a couple of parts, and it was good to go.

Well, here over the past couple of weeks, it has been having a problem. It will start up fine. It's really easy to start, always has been. It will run good for like 5 minutes or so, then it will just bog down and die, almost like it's not getting fuel. If I choke it right after it dies, it will start up again, but will only run for a couple of more minutes before it dies. If I let it sit for a couple of hours, it will start right back up and go through the whole running and dieing process again.

The first couple of times it did this, I took the carb off and cleaned it real good, but I still had the same problem. I clean the carb with carb cleaner and compressed air, and am almost positive that all the passages are open, and the jets are not clogged.

Is this a carb problem, or could I be looking at something else? I set the air mixture screw according to the clymer manual, but could that be it? Could it be something other than the carb, like the valves or something?

Any help would really be appreciated.

Thanks.

 

Sounds like the float bowl to me and or the pilot jet is not adjusted properly. If it dies like it is not getting enough gas - could also be an air leak in the intake manifold. It is leaning out too much to burn and dies - too much air.

 

That must be why it runs again when I choke it. I am thinking about just getting a whole new carb for it, cause I feel like I am banging my head against the wall adjusting this one. I was just concerned that the problem may lie elsewhere and not in the carb.

Thanks for the help!

 

See I have a 86 trx 125 too and I bought a new carb for mine and it still won’t run unless I spray gas into the carb then it will. What does that mean

 

Is fuel getting to carb? either tank filter or air vent could be blocked. With new carbs, unless genuine, the jets or idle mixture could be set wrong. I have also had float needle stuck shut, because the protective oil inside a new carb has gone sticky.