lost spark on 76 25hp evinrude

[kawaboy-zx11]

this 76 evinrude 25 horse hasnt been run in a while, i took it to the lake yesterday and man it ran great..... then my dad was like see if it will idle down real low, so i slowed it down real slow and it wouldnt go fast again after that, brought it home to find out that there is no spark on the top cylinder. it has new points,condensers, and coils. i pulled the flywheel and everything looks good under there. only thing i havent replaced is the charging coil...any ideas what to check next? Thanks, Dennis

 

[Primeturf]

Re: lost spark on 76 25hp evinrude

Charging coil has no bearing on spark. Assuming point gap, Coil gap etc. are right. Are you checking spark with tester or used plug? Switch plugs. Tester air gap on points sytem 1/4 inch. Plug may be fouled by old oil and/or gas. It will look good but not work under compression. If you replaced coil. Check to see if plug wire is grounding under coil. Good luck and answer back PMJ

 

[kawaboy-zx11]

Re: lost spark on 76 25hp evinrude

Charging coil has no bearing on spark. Assuming point gap, Coil gap etc. are right. Are you checking spark with tester or used plug? Switch plugs. Tester air gap on points sytem 1/4 inch. Plug may be fouled by old oil and/or gas. It will look good but not work under compression. If you replaced coil. Check to see if plug wire is grounding under coil. Good luck and answer back PMJ

i been checking it with a timing light, the lower cylinder makes a strobe light when i pull it, the upper cylinder does nothing. Thanks, Dennis

 

[kybill66]

Re: lost spark on 76 25hp evinrude

One more thing it could be is that the timerbase is worn out it is make out of brass and over the time it gets loose and when you give the motor throttle the base could move up and down that makes the points open and close when it wants. The one thing you can do is pull it off and take a center punch and go around on the inside all around it this will make a tight fit know and it might last you for a couple more years

 

[Howard Sterndrive]

Re: lost spark on 76 25hp evinrude

check out this thread.... it's very cool what the guy did on his '76 25HP to restore weak spark on 1 cyl.

http://forums.iboats.com/showthread.php?t=279981

 

[kawaboy-zx11]

Re: lost spark on 76 25hp evinrude

well, i took the points and condensers off and put them back on. and its fireing on both again. i did notice when i looked at the cam, there is a place that says "set" and when i set the points origonally i used the flywheel key instead of the word set. but its all good now. Thanks, Dennis