WoodTRD
02-03-2011, 12:08 PM
I recently noticed my 400ex smokes a little when you let off the gas. I'm assuming the valve seals are starting to leak a little, but it doesn't smoke on startup, just when it gets warmed up good and I let all the way off the throttle from a decent rpm. I did install a white bros e series slip on from a bike that had been smoking bad about 8 hours ago so it could be just getting hot enough to burn oil residue from the other bike off the inside of the pipe, what do y'all think? I checked the compression just to be sure and it's perfect at 120psi, so pretty sure it's not rings.
The journals on the head that's in my bike were a little worn last time I had it apart, so I have a spare head at the machine shop getting new exhaust studs right now and am planning on new valve seals going in it, lapping the valves, and throwing a stg 1 hotcam in it with a xr400 headgasket when I swap it over. With 120lbs of compression I don't think I'm going to worry about
doing rings right now, it runs perfect other than the bit of off throttle smoke. I'm pretty much at the end of my winter budget and plan on doing a 11 or 12:1 416 next winter.
Im at about 150 ft above sea level, my setup has a stock piston, white bros slip-on, sparks 6 degree key, uni with filterskin, no lid, 155 main, stock pilot, and will be getting a fresher head, what I believe to be a stage 1 hc (more on that when it gets here), and xr400 headgasket. Would there be much of a noticeable benefit from a light diy port and polish on the exhaust side and smoothing out the flaws on the intake side along with smoothing out the header welds while I have it off?
I have the xr headgasket already, haven't ordered the valve cover gasket, cam tensioner gasket, or valve seals yet though, any reason to go with Honda or cometic on these or would cheaper ones work just as well? Thanks
The journals on the head that's in my bike were a little worn last time I had it apart, so I have a spare head at the machine shop getting new exhaust studs right now and am planning on new valve seals going in it, lapping the valves, and throwing a stg 1 hotcam in it with a xr400 headgasket when I swap it over. With 120lbs of compression I don't think I'm going to worry about
doing rings right now, it runs perfect other than the bit of off throttle smoke. I'm pretty much at the end of my winter budget and plan on doing a 11 or 12:1 416 next winter.
Im at about 150 ft above sea level, my setup has a stock piston, white bros slip-on, sparks 6 degree key, uni with filterskin, no lid, 155 main, stock pilot, and will be getting a fresher head, what I believe to be a stage 1 hc (more on that when it gets here), and xr400 headgasket. Would there be much of a noticeable benefit from a light diy port and polish on the exhaust side and smoothing out the flaws on the intake side along with smoothing out the header welds while I have it off?
I have the xr headgasket already, haven't ordered the valve cover gasket, cam tensioner gasket, or valve seals yet though, any reason to go with Honda or cometic on these or would cheaper ones work just as well? Thanks