Engine misfire low revs

SOURCE: misfire & spluttering when warm

Hi wayne

Not knowing what you have checked or done already, I would first remove the spark plug from the bike and check it fir a carbon deposits. If it has not had a new one for a while, Just get a new one and replace it. Before I drop the oil for a service(as it can dirty up the oil), I also like to run a fuel system cleaner additrive(I use a Nulon product) to my bikes every few thousand kays, just to keep everything tip top. If you still have misfire problems, then it will most likely be a faulty sparkplug cap, ignition lead or other ignition part. Change out/clean spark plug with a wire brush first. I think that will fix it for you. If you still have problems,happy to talk to you more about it.

regards
robotek

SOURCE: feels like a misfire

It's time to adjust the valves. You have tight valves and most likely need to adjust the cam chain. This is classic when the valves are tight. Most likely you can start it up when cold ok but after a few minutes performance deteriorates this being due the valve lash being to tight.
The miss fire is due to a lean situation.

SOURCE: engine kiking and bucking and backfireing

1. The jets in the carb need cleaning,
2. You should Also clean or replace the spark plug,and air filter
3. Have the timing checked

SOURCE: hi, i have a 2001 YZ250 and have been having a

If you have added aftermarket pipes then you could have a fuel mixture problem, or even dirt or grime in the fuel path, I would either rejet the carbs or I would do a good fuel system cleaning.

SOURCE: i have a honda CB400 super four and have been having a slight pro

Your carb may be adjusted a little lean. Try adjusting the needle, keeping track of the changes you make, and blipping the throttle full to check the result.