78 evenrude 35 hp

[jrboat2011]

When trying to start, engine will start, runs ,then backfires or pops thru exhaust, then dies

 

[hidef]

Re: 78 evenrude 35 hp

Did you reverse the plug wires?

 

[Daviet]

Re: 78 evenrude 35 hp

Usually when you get a backfire or pop out of the exhaust it is an indication of a lean mixture, is the low speed needle set properly? Might be time to overhaul the carb.

 

[jrboat2011]

Re: 78 evenrude 35 hp

Thanks , I will rebuild the carb, and set the mixture @ the recommended settings, The Mixture is at 50:1 with the recommended mixture screw at
1 and 1/4 turns to rich, maybe I need to start there and advance the mix until it stops the pops,

 

[jrboat2011]

Re: 78 evenrude 35 hp

the plug wires set coil to plug, top, and coil to plug bottom, can;t reverse as it is a 2 plug system and the plug wires are to short to cross,
but thanks anyway.

 

[EN2]

Re: 78 evenrude 35 hp

Check flywheel key.

 

[Haffiman]

Re: 78 evenrude 35 hp

It may be a case of a double firing power power pack.
Two ways of testing.
1: Hook both plug wires to a spark tester, crank the engine. The spark should go 1-2-1-2-1-....
If both are firing at the same time, either top or bottom, 1&2 -2-1&2-2-...., you either have a defective power pack or a spark jump in the sensor connector going to the pack from the sensor under the flywheel.
2:Mark both cylinders on the flywheel when in TDC. (cyl 1 is already marked)
Attach a timing light, crank the engine. When hooked to #1 - you should only see the marks from #1, similar when hooked up to #2. If you may read both marks, when hooked to either #1 or #2, double firing.