'93 Evinrude 40 won't start

[jeffh8]

Motor ran OK last week,now won't start. Fuel is good,carbs are full, primer works, compression good (110and115 psi),spark looks weak(new plugs). Is there a better way to test the spark other than just looking at a plug held against the head ? What would be a likely cause of weak spark? Any suggestions much appreciated. Thanks Jeff

 

[fireman57]

Re: '93 Evinrude 40 won't start

You need to get a spark tester that will show how far it jumps. Should be one at AutoZoners for about 10 bucks. It needs to jump about 1/2" with a bright blue spark and a loud "snap". Possible causes are weak coils or bad pwerpack/cdi.

 

[jeffh8]

Re: '93 Evinrude 40 won't start

I bought a spark tester and found the top cylinder spark won't even jump1/8 inch. The bottom is better, but not 1/2 inch. Any thoughts on whether the coil or the CD unit is the most likely culprit? Thanks

 

[fireman57]

Re: '93 Evinrude 40 won't start

The chances of two coils going bad at once is slim. You can test your cd unit with a dva meter. do a search for the how to on here. There will be a link to cdi electronics trouble shooting or something like that. They have a website that is very good and walks you step by step on how to test them.