76 85hp Hard Starting and Backfires

[rade0041]

I'm new to outboards and I'm stumped. This motor is hard to start as if it were not getting enough fuel. Sometimes, after it starts I can shut it off and it starts right back up, sometimes it doesn't. I changed the fuel tank, lines, pump and rebuilt the carbs. Once it is running it has trouble idling and dies when you put it in gear unless you give it enough gas right away. When idling it seems to backfire a little through only one carb throat every few seconds. Runs fine when wide open, seems to have plenty of power. I've been running it out of the water if that makes a difference. What am I missing here. Where should I look next.<br /><br />Thanks,<br />BR

 

[tashasdaddy]

Re: 76 85hp Hard Starting and Backfires

when you say out of the water, i hope you mean you are running it on muffs. if not it will burn up the impeller in an instant. could be timing, linc & sinc, dirty carbs. do you have a manual. if not order one for you specific engine, from kencook.com. should not be run over 1500 rpms out of the water. welcome to iboats.

 

[rade0041]

Re: 76 85hp Hard Starting and Backfires

Yes, I am running it with muffs. I haven't checked the timing yet.

 

[Walker]

Re: 76 85hp Hard Starting and Backfires

Coughing/sneezing/backfiring like you describe in usually a sign of a lean fuel condition with the most likely culprit being carburator/carburators. I believe your carbs have idle mixture screws. Turn them all in until they gently bottom out. Open them all 1.5 turns and then start adjusting them from there one at at time 1/8 turn at a time. Allow the engine to run for 15 seconds or so after each adjustment. Tune it by ear. Whne you get the best/smoothest rnning with each arb stop adjusting that carb. If this doesn't work then I suspect your carbs aren't clean enough.

 

[rade0041]

Re: 76 85hp Hard Starting and Backfires

These carbs don't have idle mixture screws. I cleaned out all of the jets when I had the carbs apart by spraying carb cleaner through them. Maybe I should try cleaning them again. Can you buy new jets?

 

[fireman57]

Re: 76 85hp Hard Starting and Backfires

If you really clean them well you will take them apart and soak them overnight in a good cleaner. You will remove the small welsh plug and clean garbage out behind it and replace it with the one that you get in your rebuild kit. You will replace the needle valve and other parts in your kit that pertain to your engine. Blow everthing out with your air compressor and set the float.