1988 evinrude 150 xp

I need help figuring out what is wrong with my motor. I was running the boat across the lake yesterday when I noticed the motor lose power for a split second then right back to normal. It did it for the rest of the time I ran the boat. When I got ready to head back to the ramp it was worse. It happened the whole way back which was about 3 miles. Did it worse at 55 mph that at 35-40. Could it be a coil going out or power pack? Y'all's help would be awesome.

 

Welcome to the forum.

The very first part you should buy for the boat, is the repair manual for the outboard you have on your boat. There's a lot of reasons an engine can intermittently lose power. Most are usually fuel delivery related. What have you done so far to diagnose the situation?

 

I have had the boat for 20 years and have never had a proble with it until now. Iam sure its not a fuel problem. It was harder to start than normal the day I had the problem. What are the symptoms of a coil or power pack failing.

 

If the coil fails, you have no spark to that cylinder, and revs will drop fairly noticeably even in a 6-cylinder motor. It may be that one has been causing the problem. It is easy to check, get a workshop manual and follow the test procedure, which is nothing more than using a multi-meter to check resistance across the terminals of each coil, one by one. The manual will specify the normal range. I would also check the plug leads to make sure there is a good circuit, if they are faulty it will destroy a new coil in short order. Of course it may be nothing more than a faulty plug, in which case the bad one should look a little different to the others with the colour or wetness of deposits on it. Or you could lash out on a brand new set.

 

How is it that you're sure it's not a "fuel problem". This isn't what I mentioned, but I understand your confusion. Fuel "delivery" issues are the bulk of the problems pleasure boats experience, other than failed or broken parts. The fuel can be fine, but it's the parts within the related systems, that usually let you down, typically without previous warning.

 

Remove the spark plugs and compare them with the pictures in any car service manual.
Check the gaps, color and deposits.
If you can reach 55 mph failure of coils or power packs can be excluded.

 

Certainly wouldn't get 55mph if he dropped a coil, but there may have been an intermittent problem.

 

in the USA first thing i would be chasing is fuel issue as the fuel is crap, one shot of ethanol then leave your engine for a few months and carbs have glue in them.
Carbs are simple, 20 years it way overdue

 

Thanks for all the in out but I ended up having a bad coil.

 

As I mentioned earlier, check the plug lead is good, if not it will destroy your new coil quickly.