82 115 evinrude backfireing

[AquanutZ]

ok, i bought ths boat about 2 months ago and im not too familler with outboard i know the basics and what ive learned from the book, well since i got the boat i took it out to lake havasu and it ran pretty good start right up exept my last day on the water i got a little ballsy and punched it and it kinda hesated and then took off so i figured it was the carbs i took it home and clean them up, about 2 weeks ago i took it 2 silverwood like and it ran like sh**t didnt wanna start 4 like a half an hour and when it start at about 4800rpms it would bog down then turn off so when i got it home i took a look at the motor i noticed spark plug wires were getting old and starting to crack so i repaced them with some accel copper core wires i saw a post that said they would be ok it seems like it iddles better but now at idle it backfires like every 30 seconds and will shut off i cant figure out what i could be.are those wires bad 4 the motor?if not what else could it be?oh yeah and when i started it last it was on the hose. any answers will help

 

[Joe Reeves]

Re: 82 115 evinrude backfireing

By backfire, I assume that you mean the engine is spitting back somewhat, sort of a mild backfiring back thru the carburetors rather than a loud backfiring out the exhaust.<br /><br />If so, you've overlooked something in the carburetors which needs cleaning, the float levels are incorrect, the jets are in the wrong location, the carburetor throttle butterflies are opening too soon, or at idle the linkage between the carburetors is set wrong where one throttle butterfly is shut as it should be but the other is slightly open. Both should open and close at the same time.

 

[AquanutZ]

Re: 82 115 evinrude backfireing

thanks 4 helping me joe i see alot of post from you and you really know your stuff its making a poping noise out of the prop exaust im not sure what that would be called

 

[dzoolk]

Re: 82 115 evinrude backfireing

whats the top speed on that rig?

 

[Joe Reeves]

Re: 82 115 evinrude backfireing

If you or someone else has had the flywheel off, it's possible that the flywheel nut wasn't torqued properly. This may have resulted in a slightly sheared flywheel woodruff key.<br /><br />Normally if that key shears, the engine is thrown out of time and won't run at all, but there are exceptions. Something worth checking. The nut torque is 105 foot pounds.<br /><br />Be sure to check compression and spark. The spark, with the plugs removed, should jump a 7/16" gap with a strong blue lightning like flame.... a real SNAP.<br /><br />Spark plugs should be Champion QL77JC4 plugs, gapped at .040 .

 

[emdsapmgr]

Re: 82 115 evinrude backfireing

Be sure the spark advance rod is connected and that the timer base moves with the throttle. If this becomes disconnected, it can have the same sypmtoms.