Noah Adams Posted March 27, 2009 Share Posted March 27, 2009 I've got an '83 XS400k Maxim with 7500 miles on, that I'm having some issues with. Since I got it around for spring, I'm having issues with the engine once it's warm. Now, I should explain that I did have the carbs apart, but only for a cleaning. I didn't remove any of the needles, but I did replace the float valve and seat, and put new bowl gaskets on. Got the bike back together, fired it up... seemed fine, was running strong. Took it out for a ride, and immediately had issues. Bike would run fine up to 4-5k RPM, and then start spitting and sputtering. If I backed off the throttle to just maintaining speed instead of trying to accelerate, it would clear out and maintain 5k rpm. Any attempt to accelerate past this leads to the same result. At first, I was thinking that it was starving for fuel as a result of me knocking some chunk of something loose in the carbs. So, I get back to the house ,and pull the plugs. Both of them were as black as anything I've ever seen. Okay, so we're fouling. Thought at first maybe it was just because they're last seasons plugs, so I replaced them. New ones do the same thing. Once the bike is warmed up, the issue is able to be replicated even at idle. Give the throttle a crank, and sometimes it'll make it all the way to 7k, then start sputtering and slow down to around 4 or 5. Right now, I'm considering pointing my finger at the ignition system, only because I didn't touch any of the carb settings... just cleaned. One question is, does this bike have electronic ignition, or points? I know it has some electronics hiding here and there with heatsinks on them and such, but I'm not sure what type of ignition it has. Any thoughts from those more experienced that me? Link to comment Share on other sites More sharing options...
david coppler Posted March 28, 2009 Share Posted March 28, 2009 too rich, clean, remove, or replace air filter. Link to comment Share on other sites More sharing options...
Noah Adams Posted March 28, 2009 Author Share Posted March 28, 2009 too rich, clean, remove, or replace air filter. Was running it with no air filter while testing (carb boots are a 30 minute ordeal to get on and off) and it was still having the issue. I took it to a local bike mechanic that I trust... he's going to give the bike a good look over while he's at it (good for a bike this age). I'll let you guys know what he finds. Link to comment Share on other sites More sharing options...
Recommended Posts