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Big Bear 400 Running Poorly

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Old 07-24-2013, 09:43 PM
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Default 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!
 
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Old 07-25-2013, 10:18 AM
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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.
 
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Old 08-12-2013, 07:59 PM
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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!
 
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Old 08-13-2013, 08:16 PM
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Is your float stuck? I'd get that carb out and do some work on it.
 
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