I have a bvm 200,it will start but want get up to regular high spee and backfires what is wrong?
If it is backfiring when you are moving the throttle to increase air speed (along with not getting to top speed), the engine is running too lean, which means it is getting too much air and not enough fuel. You need to check the following things to find out what the problem is. Does it start on full choke? Does it start on half choke? If it runs when it is choked and there are no backfires when it is choked, the engine is definitely running lean. There are several things you can check, I am providing a list for you:
First, check the muffler and make sure it is solid and on the engine exhaust port tight.
Next, check the air filter...if there is no air filter put one in!
Check the fuel filter in the tank, if it is clogged, the motor isn't getting enough fuel.
If all of these things check out ok, you will have to check the carburetor. When you inspect the carburetor, check and make sure it is clean. I don't think you will have to mess with carburetor adjustments, not unless you tinkered with it before coming here.
If all this checks out good, then you could have an air leak around the intake. The intake is the black piece that sits between the carburetor and the engine, there are two gaskets on this piece, one on each side, one or both of these could be deteriorating and allowing excess air...it's a longshot but it could give you the problem you are talking about.
Try these and come back here if you don't find any of these things and let me know. We can move deeper into the engine if necessary but my bet is either the muffler needs to be tightened or replaced and the fuel filter needs to be replaced. Good Luck!
Nov 08, 2009 |