Fuel/Air mixture backfiring out the carburetor

[liv2soar]

My 1986 Bayliner with an AQ-131 4 cylinder inline inboard/outboard isn't running too good.<br /><br />In nuetral it runs great all the way to the redline. <br /><br />When I engage the prop, it starts backfiring a fuel/air spray out of the carburetor. <br /><br />What might this be?

 

[Northern Eclipse]

Re: Fuel/Air mixture backfiring out the carburetor

Could be bad timing, Check timing belt if its 18 years old it may be time to replace, check points and advance weights in distributer, for wear and rust. may be a weak coil also, start with the simple stuff, like the ignition system but do some diagnostic first, don't just toss new parts at it. If you need help you'll get it here but you need to do some homework first, because anything right now is just a guess, let us know what you find.