I couldn't pass up on it after seeing it on Craigslist since it was complete, in decent shape and it's a 400! That ought to be an upgrade from the 175! After having it for a few days, I discovered issues the seller kept his mouth closed about:
--The bike is quite hard to start. I have to jump on the kicker and give it some gas in order for it to start within a reasonable amount of time. It takes about 6 kicks if I'm feeling lucky, but I've seen lots of these which start within one kick!
I'll also add that it makes a loud hiss exactly like the sound of removing an air tool from a compressor if I hold the throttle open. Sometimes it backfires too.
--Idle speed is quite high at 2,000 RPM. Trying to adjust the carb following the manual results in very hard starting and it stalls frequently when warm.
--It runs somewhat spotty between 3-5,500 RPM. It sounds like it's firing every other stroke and power feels jerky/mushy but it's very very subtle.
--Neutral is not easy to find. Takes a few tries.
--It really likes to burn its lights.
I've done a compression test and I got 120PSI cold. I put some oil in, the compression went up to 130 and it got very hard to kick over. I cleaned the carb out, and put fresh gas in. Petcock allows gas to flow freely. Spark seems OK.
My guess is that it just needs a new top end. It does have 6,100 miles on it. I've been pulling my hair out trying to outsmart this thing...what do you guys think?