Help!

[straughn]

I am trying to get a 1986 KDX running properly. Bought the bike last fall and rebuilt it over the winter. It has an FMF pipe and silencer. The reeds look good and it has a new air cleaner. Timing is in the correct location and the piston/rings are within tolerances. Went with Fredette's starting point on jetting. 30 pilot,320 main and needle in the middle position. Lowered the needle clip to the top position but still running fair at best. Went out to a bike park yesterday and rode for several hours. Midrange and top end were ok, but the low end wanted to load up. The bike eventually loaded up and quit running. Pulled the plug and it was black but not carbonded up. Put in a new plug and it fired right up. It seems to be overloading. I have tried a 25 pilot but it ran worse. I admit I am terrible at jetting. Is there some other problem I should be investigating or do I need to keep working on the jetting? Appreciate the help.

 

[bultaco4ever]

Follow up to Straughn's 'help' plea: I was following him all day on my KDX. He went up a steep hill without enough initial speed and came to a stop two thirds of the way up. The bike was at an angle as he tried to rev wildly and fan the clutch to finish the climb.

At this point the exhaust started smoking badly and I told him that the floats or float needle might be allowing too much fuel in.

Could this cause a rich low rpm situation?

 

[glad2ride]

Yes, check the float valve. Turn off the fuel at the tank for a few seconds to see if it clears up (without fuel starving it by leaving it off for too long). It is 24 years old, so the rubber tip may be worn away.

 

[bultaco4ever]

This report just in: New float bowl needle seat and a new, unworn needle jet cures problem! Running much better now.