Big Bear 400 Running Poorly
 

I inherited a Big Bear that had been sitting for a long time. Last hunting season the bike was taken to someone to get it running better. All that I can tell they did was change the air filter, spark plug, and put a new carb on. The bike sat until a month ago when I got it.

So here is the problem the bike will start missing bad when it is at half to three quarters throttle. I have drained all the old gas out of the bike and even took the new carb apart to blow air through it because I thought it could have been clogged. I put the carb back on and it is still doing the same thing. The bike idles great and will run fine at low RPMs.

I just don't know where to look or what to do next. Could it be a spark issue? Any insight on what I could check next would be great!

Needle jet probably. It needs to be cleaned and/or the needle needs to be raised up a notch or two. Needle has 3 settings. Raising it up will give it more gas through that power band. The pilot jet is for low end problems, and the main jet is for high end WOT problems.

So I have not had time to work on the carb and adjust the needle jet. But Iwent out today and started the bike just to let it run for a little while. WhenI opened the fuel valve gas started pouring out where you can drain thebowl. Is there supposed to be an o-ring that goes on the boltthat you turn to drain the bowl? If not why would this be leaking?



Thanks!

Is your float stuck? I'd get that carb out and do some work on it.