Blubbering and drooling, need advice

[Tumbleweed]

I have very little mechanical knowledge so I wanted to see what you guys might think. I bought my '91 kx 500 about 8 months ago for $500.00. The bike was (is) a twisted mess, I probably could have made my money back parting it out, but these bikes are uncommon in my area so i decided to try and nurse it back to health.

The guy I bought it from never got it started, so it sat in his YARD for over a year. I tried contacting him after I bought it to try and get info, but he moved away and never returned my emails or phone calls.

I'm pretty sure he tried a lot of things to get it running, because the float was bent up, (twin floats) one was higher than the other and the spark plug was brand new.

I'm pretty sure the kickstart lever was the problem because the pin broke and it rotated past the stopper, resulting in poor leverage. I bought a new kickstarter and it fired up, but major spooge from the pipe blasted the rear fender and drooled down on the swingarm. I was running klotz r-50 at 40:1 at the time. I rode it once but the the bike blubbered and never ran clean.

I pretty much gave up on it for a while wondering how bad things were in the engine. I recently pulled the top end and was very surprised that the cylinder was in excellent shape and the piston had no scoring. Just some mild blow by on the piston but the power valve is carbonized to heck but it's not seized.

I took apart the carb today and was positive I would have to go smaller on the jets, but it has a 150 main and a 55 pilot, which seems small compared to what other people are using. I ride at sea level 60-90 degrees.

What could be other factors? I still have to check the powervalve if it's timed correctly but the retension screw is rounded and I have to get a screw extractor.

another thing that concerns me is the bike has a boysen rad valve but the (boot) that connects it to the carb looks like a piece of a car radiator hose 

I really want to get this baby going, but the puzzle doesn't seem to be falling into place. 

[kaw rider]

how much compression did it have. was it hard to kick over. if the float was set to high then maybe the seat was seating and flooding the engine.

[Hillclimb#42]

 It could have a plugged up silencer. A carboned up powervalve will run like the choke is on. The stock intake is rubber and often is cracked, but rarely all the way thru. Check by spraying with carb cleaner or wd-40 while idling to check for leaks. You can hear the change in rpm's if it leaks. jetting on a motor with good compresion, should be around 58 pilot, 168 main, and clip at 3rd position. It may need fattened up a little as it wears. Floats are very important to tuning. Sounds like you need a new set. Good Luck

[Tumbleweed]

how much compression did it have. was it hard to kick over. if the float was set to high then maybe the seat was seating and flooding the engine.

I don't have a compression tester, but the compression "seemed" ok when you kicked it over. The float is what worries me, I bent it back, but not positive it's completely straight. I think I'll order a new one.

[Tumbleweed]

It could have a plugged up silencer. A carboned up powervalve will run like the choke is on. The stock intake is rubber and often is cracked, but rarely all the way thru. Check by spraying with carb cleaner or wd-40 while idling to check for leaks. You can hear the change in rpm's if it leaks. jetting on a motor with good compresion, should be around 58 pilot, 168 main, and clip at 3rd position. It may need fattened up a little as it wears. Floats are very important to tuning. Sounds like you need a new set. Good Luck

I will clean the powervalve and change the float. most likley change the jets also. thanks!