I'm at the end of my patience with this thing. A few years ago I upgraded from stock to a pwk33 carb. I haven't been able to get it running right since. I originally had it running decently until I lost compression, the rings were burnt up. I cheaped out and replaced just the rings then jetted it rich as hell just in case. Seemed to run good after that, then on the way to the trail it started revving high as crap. Shut it off and towed it home to find the intake manifold cracked. Replaced that and got one good day of running out of it. Went out for about three hours. The next day, I make it around the block and it dies. No compression. Pull the top end to find the rings melted to the piston and the cylinder badly scored. Fast forward a year and I just got it back from being bored and honed, (73mm), got it installed with a wiseco piston.
I only get it to start with the choke on. Push the choke in and it wants to die. I have to stay on the throttle to keep the rpms up, responds very sluggishly, ad if the rpms get too low it dies, regardless of throttle.
So I get it through three heat cycles like that. Compression is at 155psi.
Then I set about to actually get it running decently. Seemed like it was running rich so I went from 170/55 jets down to 155/50. Still does the same thing. Will only start with the choke on and rpms are really high, turn the choke off and it dies. Giving it suppose throttle it slowly bogs and dies. Completely removing the air screw and the airbox/filter slightly improved it, but only a little. Pulling the carb it looks like there's a lot of fuel residue in the intake boot, and the plug comes out black and wet.
The carb has been cleaned, the float height is right at 16mm. I have a 40 and 45 pilot jet on the way, but from what I've read I should be able to get it to at least start and run with those jets. I'm close to putting the stock carb back on and giving up on this thing.
Mods are an fmf fatty and silencer, no lid, k&n filter, vforce 4 reeds, pwk33 carb, vitos bbk at 73mm bore.
I only get it to start with the choke on. Push the choke in and it wants to die. I have to stay on the throttle to keep the rpms up, responds very sluggishly, ad if the rpms get too low it dies, regardless of throttle.
So I get it through three heat cycles like that. Compression is at 155psi.
Then I set about to actually get it running decently. Seemed like it was running rich so I went from 170/55 jets down to 155/50. Still does the same thing. Will only start with the choke on and rpms are really high, turn the choke off and it dies. Giving it suppose throttle it slowly bogs and dies. Completely removing the air screw and the airbox/filter slightly improved it, but only a little. Pulling the carb it looks like there's a lot of fuel residue in the intake boot, and the plug comes out black and wet.
The carb has been cleaned, the float height is right at 16mm. I have a 40 and 45 pilot jet on the way, but from what I've read I should be able to get it to at least start and run with those jets. I'm close to putting the stock carb back on and giving up on this thing.
Mods are an fmf fatty and silencer, no lid, k&n filter, vforce 4 reeds, pwk33 carb, vitos bbk at 73mm bore.