so I seem to have fixed my bog problem by adjusting the air screw,, it seemed backed out too far..after a bit of slow riding it would not start easily,,however once i tightened said screw started right up??? My issue is now I can only shift into low forward and reverse and get it to run and that is after hard grind shift..when I try to put it into forward hi,,it just stalls..any ideas..I am thinking belt perhaps,,but cannot pull cover at this time??thanks in advance

 

your problem is with the jetting in your carb. The dead givaway is that it will run with the air screw out. Did you recently put a pipe on your bike? What are you riding? If no new pipe, have you cleaned the air filter lately?

 

It is a 1987 Trailboss 250..I picked it up for $100 and have done a little tweaking to get it to start and stay idled. Have not put a new pipe on although it probably would not hurt to clean it..The air filter is pretty dirty and am planning to get new one soon. Have not taken the carb off yet but was wondering why it may rev up with no issues in neutral but bog in gear..could it have anything to do with the clutch belt or buttons...

 

If the jetting is wrong, the bike will die under load. I am certain that the 250 is a two stroke, some people mess with the jets thinking that it will make the bike faster. It won't. Have you tried to ride it without the air filter? It is a quick check to make certain that the bike is getting enough air. Pull the spark plug. It should be a golden - or semi dark brown. If it is black and wet, the carb is getting too much gas. Also, might be worth cleaning getting some carb cleaner and cleaning hte carb. the bike is pretty old and might have sat for a long time...