85 90 hp evinrude power problem

[philip44]

runs good on muff put it in water dies but when it gets going on wot front lifts up but has no speed new plugs and wires carbs done about 3 months ago

 

[SparkieBoat]

Re: 85 90 hp evinrude power problem

carbs may need to be done again...check fuel lines and connections, try pumping bulb and see if it helps, check spark with a spark gap tester. check compression

 

[philip44]

Re: 85 90 hp evinrude power problem

compression good 110 on all 4 cylinders pumping the bulb dont help and gap on plugs are good

 

[emdsapmgr]

Re: 85 90 hp evinrude power problem

Double check the spark on all 4 plugwires when the engine warmed up and is under load. An inductive timing light makes this job easy.

 

[SparkieBoat]

Re: 85 90 hp evinrude power problem

I meant to go to an auto parts store and purchase a spark gap tester, you should get a strong spark with a 7/16 gap on each coil. After you have eliminated fuel and compression you are pretty much left with ignition. CDI electronics has a great troubleshooting guide in the support section of their website. you will need an DVA adapter and a multi meter, to preform test outlined. could be spark failing under a load as EMD mentioned. but a spark gap tester is cheap and great way to find weak/bad coils.