88 force 50, bottom cylinder is back firing.. any suggestions

[cron416]

I have a 1988 force 50, was not getting any spark in bottom cylinder...switched out coil and now it is getting spark but when it cranks it starts to backfire and does not start, top cylinder starts fine compression on both is at 120.... so now im stumped any suggestions?

 

[MikDee]

Re: 88 force 50, bottom cylinder is back firing.. any suggestions

It's backiring out the carb, or exhaust??? if backiring out the carb, it could be too lean in that cylinder, not getting enough gas, if backfiring out the exhaust, you might have a broken, or stuck open, reed valve.