Motorcycle Repair: 1979 honda XR 185, honda xr, bill silver

Question
I just got my dads old bike from the lake and its been sitting for a while.  I took it all apart and cleaned the lines, relaced the gas, new plug and all the stuff to get it running...  I did get it running and got it idling nice and everything.  I took it out on the road and it started to sputter and bog out once I got the throttled opened about 3/4's  and then wanted to die.  I got it back to the house and started it again and held throttle open about 1/2 way and it sputtered.  runs fine at lower rpm but cant open it up at all.   ANY IDEAS????????

Answer
Paul, if the intake/air filter and/or the exhaust system parts have been changed since the bike was built, then the carbs may need re-jetting. The carb, petcock and fuel tank all need to be cleaned thoroughly.

If it is all stock and/or it was dialed in and running well before the long hibernation, then the spark advancer may have frozen up from sitting. See reference below:

http://www.cmsnl.com/honda-xr185-us_model1152/partslist/E++02.html
Item #3.

Check also for intake manifold leaks at carb connection and at the cylinder head.

Bill Silver