I give up XR80 wont stay running. Max idle and dies

[fungames43232]

I've read and read, but can not come up with an answer. I have a 90 xr 80 and it seems to run fine when I first start it up. As it warms up it will no longer run correctly. it just dies. I have taken the entire carb apart multiple times to clean it. I have replaced the points and still no dice. I was going to try an e-bay carb just to see if thats my issue. They are only $29. I do have an xr100 but its a 94. Can I just swap the carb out for testing purposes?

[fletchman919]

The 100 carb won't help. Check the entire intake system. The filter, boot and air holes. Be sure they are clean. Check for a plugged hose on the carb. I would check the pilot jet real good again. It you are not removing all of the dirt, it can keep getting clogged. It sounds like a fuel mixture problem to me. I have had to clean carbs multiple times myself. I don't know why, but I wasn't getting them clean.

[Leardriver]

Either a partially plugged pilot jet or a vent problem, like a clogged gas cap vent.

[fungames43232]

good calls..I ill try taking out the filter and gas cap and see how she runs. I didn't even think about those. I did take the screen out of the filter and put a new filter cover on.

[fungames43232]

Ok I know this is going to sound strange, but I took off the gas cap air filter cover, airfilter and seat and she seems to run pretty good. I put the gas cap back on and no change. I put the air filter back on and seems no change. I put the air filter cover back on and I could hear a distinct difference in idle. When I put the seat back on she still ran but started to bog. I've never heard of a seat causing a bike to bog. Anyone ever heard of that?

[fletchman919]

Hahaha! No! Is the air filter clean? If it's dirty or oil saturated, then it's having a hard time breathing.

What's the plug look like? The plug can answer questions sometimes.

[fungames43232]

The air filter should be fine. I cut the screen out and got a pre-oiled filter from Iron Pony to slide over it. The top of the air box is broken a bit. I just thought it was strange.

[4strokeridertt]

Sounds like the space between the top of the airbox and the seat might be restricting airflow, but I can't imagine how. Take a good look and see if maybe the seat pan is crushed down onto the airbox. The airbox being broken may be your clue and a good starting point, they don't usually break.

[socalxr]

Try it with the airboot off, try the other carb, low out the pilot. Afer that I would be looking into a CDI/points swap.