Hi everyone I am new to the forum and I am at my wits end dealing with carbon or soot deposit on the firing end of the spark plug in my 1998 Honda 300 Fourtrax, which is restricting the running of the machine. When I engage the throttle the machine bogs down and will backfire.. This issue started after installing a new Carb on the machine last summer. Everything went find on the install. I then adjusted the Carb per specification given in the manual. Everything seem to be working all right until I took a test drive when I found out something went wrong. Thing I know are:
1. I have tested or checked the spark on the tip of the spark plug and It looks pretty good to me. So the spark plug is firing.
2. I have install a new Air filter in the intake box.
3. I have checked the gap on the plug.
4. Spark plugs I am using are all new. I even tried a hotter plug, but got the same results.
What is very strange to me is that the carbon buildup on the plug happens immediately, within five minutes after starting the machine the firing end of the plug is totally black.
I can only assume that the New Carb which is an after market replacement for the original that I used is a piece of crap. Maybe I need to re-install the old OEM Carb and see what happen before moving on with this issue.
I look forward to getting any suggestions concerning this issue.