My foreman has been bogging down lately. I have tried most of your suggestion from draining the carb bowl to checking the air filter but nothing seems to work. I recently noticed that when i pulled the air filter there is a heavy flow of air coming back into the air box through the carb. Any reasons as to why this is taking place. It should be sucking air not pushing it back out right? Is there a valve problem?

 

Check your exaust to see if it is flowing

 

I checked the exhaust and there is still air coming out at the tailpipe. Is there another way to check the exhaust flow and what are the reasons for bad flow. I have also noticed a small exhaust leak. Could that be where my bad flow is coming from? At first i thought my choke was stuck but that didn't seem to be the problem. Thanks for your help. I am just surprised to have this kind of problem. My bike only has 700 miles on it and it hasn't been rode hard. I do know it had a top end rebuild recently because the previous owner used the wrong oil. Could that be the problem?

 

have you tried cleaning out the spark arrestor? there's a metal plug at the end of the muffler on the bottom. take a shop rag and hold it over the normal muffler outlet so the exhaust comes out the plug hole, careful not to burn yourself or anything. start it up and rev it up a couple of times. If a bunch of crap comes out, keep revving it until it's cleared out. If no exhaust comes out at all, then your muffler is plugged. It might flow freely through there and no crap will come out, then it's fine and not plugged.

 

It might help if you were to describe exactly what was happening when it boggs down.
Mid-range? Top end? Under acceleration? Any backfiring or afterfiring?

You might want to check the compression also.

 

How long has it been since you checked the valve clearance. An intake valve which is too tight, will make the air come back out the carb, and make the motor run crappy.

 

Take it in and have the valves adjusted, the carb professionally cleaned and tuned, and a new spark plug installed. Make sure the electrical connections on the coil are good, as well as the connection at the spark plug. Di-electric grease does wonders on all electrical connections on a bike.

 

Hey i finally figured it out. My timing was all messed up. I am having a new timing chain installed and it should be running right. Thanks for your help.