Suffolk engine misfire under load
Hello
My 75cc Suffolk engine misfires underload.
I have changed the spark plug, unless I have 2 duff plugs, that's not the issue.
I have cleaned the points and have a strong blue spark
I also cleaned out the carburettor to rule that out.
The misfire under load does get better if I adjust the main jet for a leaner mix.
I have also replaced the air filter.
Do you think it is likely to the coil? Or condenser?
The engine starts and runs fine. The problem only starts under load.
I just wonder people's thoughts as a new coil is quite expensive.
Could it be a build up of carbon in the engine ?
Thank you for your help.
Forums
Thank you again for your…
Thank you again for your help.
I have check the valve clearances and they were ok. But might check them again to be sure.
I think the coil may be playing up at the engine has started cutting out when hot.
George at Villiers part sells exchange wipac ignition units.
The misfire makes a heavy note down the exhaust if that is something you have come across before . Wondered if that would point to the problem?
“Do you think it is likely…
Could be either but unless they are given a proper test , it will be guess work. Have you checked the valve clearances ?. 7thou inlet . 15thou exhaust