50hp evinrude starts then won't start?

[BURNSY23]

1980 50hp evinrude ran good for couple hours one day the a few days later ran horrible, had hardly any power and went through a half tank of gas and didnt go far at all. Now last night it started then stalled the started and stalled again when putting it in forward then it wouldnt start at all? Today cleaned both carbs, checked compression and its 120 in both, also checked spark and both are good. Started and ran for about aminute then stalled and would not start again. Please any ideas would be awsome! Thanks.

 

[Daviet]

Re: 50hp evinrude starts then won't start?

If the compression and spark are good, it still has to be a fuel delivery problem, will it run properly if you keep squeezing the primer bulb?
If it does you most likely have a fuel pump problem.

 

[BURNSY23]

Re: 50hp evinrude starts then won't start?

Its getting fuel, the plugs are wet with gas and the carb bowls had fuel in them both when taken off. And no the prime bulb didnt help it stay running. It wont even start now.

 

[Daviet]

Re: 50hp evinrude starts then won't start?

All it takes to make your engine run is timed spark, fuel and compression, one of them has to be out of spec.
Did you check spark with an air gap tester, spark should jump a 7/16" air gap and be bright blue.

 

[boobie]

Re: 50hp evinrude starts then won't start?

How did you check your spark ??

 

[BURNSY23]

Re: 50hp evinrude starts then won't start?

I simply took plugs out and placed in boot. Seemed more white than blue though. Plugs are new only 2 weeks old.?

 

[BURNSY23]

Re: 50hp evinrude starts then won't start?

Could it be coil or an electrical issue in the CD box?

 

[boobie]

Re: 50hp evinrude starts then won't start?

Re-read post # 4. Checking with the spark plugs tells you nothing.

 

[doc77]

Re: 50hp evinrude starts then won't start?

You have OK compression, plugs are wet so you have fuel, sounds like a spark issue. Have you replaced spark plugs? A plug can let spark through when testing but once under compression fails to work.
As stated above, the power pack/CD unit may have begun to fail (personally I would not think you would have any spark if this was the case), I have also seen the wire inside plug leads corroded and not allowing spark through. Stator failure can also cause similar issue.
Good luck

 

[BURNSY23]

Re: 50hp evinrude starts then won't start?

Thanks for your help!!! New plugs about 2 weeks ago so that would be odd if it were a plug issues correct? Going to replace again tomorrow and hope for the best. I hope this works but if not i appreciate your advise very much! Thank you everyone.

 

[Haffiman]

Re: 50hp evinrude starts then won't start?

Do you have spark at correct time? Might it be a loose flywheel/broken key that makes the flywheel move around and alter the spark timing?
Remove the plug in cyl #1, use a screwdriver or similar and turn the flywheel until top piston is at TDC, check that timing pointer is at TDC as well.