1988 Evinrude running at 1/4 power.... Help!

[huntingbum]

I have a 1988 Evinrude 25hp that ran like a raped ape for about 5 minutes and then dogged down to about 1/4 hp at full throttle. The motor maybe has 20 hours on it.
Figured it was the water pump since had never been replaced. Found the water pump was bad, but still pumped. Replaced water pump.
Replaced all fuel lines. Checked and cleaned the fuel filter.
Checked the carb bowl, and it all looks shiny and new.
Put in new spark plugs before I ever ran it the first time.

Not sure what to do next. I am not an expert on these motors but am mechanically inclined.
Took my 8 year old daughter out again today... She's going to stop going with me unless we can get this fixed. She's beginning to not have fun..... Help!
Any help would be appreciated.

 

[HighTrim]

Re: 1988 Evinrude running at 1/4 power.... Help!

Start with the basics.

Do you have an inline open air gap spark tester? If not, they are real cheap at auto parts stores, under 10 bucks. Get one, set it to 7/16 of an inch, and test the spark. It should jump that gap with a bright blue ZAP!! If you are only sparking on one of the cylinders, you likely found your problem. First try swapping the coil from the good cylinder with the coil from the non sparking cylinder and see if spark returns, if it does, replace the coil. If not, you will have to dig deeper.

Also cant hurt to test compression. A very important thing to do before proceeding with any repairs. If compression is bad, no amount of money into the ignition or fuel system will help you.

Check out these 2 things and let us know what you find. Good luck.

 

[huntingbum]

Re: 1988 Evinrude running at 1/4 power.... Help!

I'll check it out. I need to get an air gap spark tester and go fromt here....

Thanks.