Engine bogs at full throttle - 2001 xr80

Just picked up an XR80 that was sitting for about a year. The guy said his kid put it away and didn't ride it and he tried to start it and it wouldn't start. I took out the plug, clean it up and the thing started right up.

It ran real rough so I put in a new plug. After the new plug, it still didn't run right so I drained the gas and checked the air cleaner which looks good. Filled it up with new gas and it doesn't want to go at full throttle. I took the bottom of the carb off and cleaned it up. It didn't look too bad but it did have some gunk.

The thing runs great but bogs out at full throttle and will slow to a stall if you keep the throttle open.

Any ideas??

Should I take off the carb and clean the whole thing??

I checked the plug gap and tried running it with the air cleaner off just in case it was clogged. Still no good.

 

Yep...that will fix it.

 

did it

ok- took it apart and clean the heck out of the carb. needles were clogged.

better - but it only runs right with choke half on.

Still bogs at full throttle with no choke.

 

Carb is not clean yet. Should be obvious. You have to use the choke to make it run ok. That means the thing is lean. That means the jets ain't passing enough gas.

Go to the parts store and buy a pail of carb cleaner. Solder Seal and Berryman are two brands. I just bought the Solder Seal and the basket sucks so get the Berryman and see what it's like.

Take the carb ALL the way apart including the nozzle that sticks up into the carb bore. Take the main jet off the emulsion tube. The pilot jet orifice is so tiny that often the carb cleaner will not scorch out the crud so you have to poke a tiny wire down the hole. Take out the air screw. Then let the carb soak for an hour or so. Blow out all the passages and jets. If there is any sign of green crud let it soak some more. Put it back together with a new gasket kit. Set the float hgt. 24mm I think but you need to double check that number. I didn't work on anything later than about 95.

 

Most full throttle bobbles are from a clogged main jet. I agree with above post. the carbs are still gummy.

Good luck!

 

you can drop it in your new ultra sonic tank and walk away for a cold drink and come back to a brand new carb

 

Also check that the float bowl vent tube is not cloged.

Bugs like to get in them and die. Also if the float pin was sticking people that don't know better tend to cork them. (bad idea)

Make sure the vent line for the gas tank is not cloged too.

Petcock for the tank might have a filter thats not flowing enough fuel too.