Loss of power... Please help!!!

[mmurray70]

I have a 92 65hp 3 cyl thats causing some problems. I got the engine used and did all the carb adjustments in the service manual and the thing seemed to work really well. Tried it a couple times, burned a tank of gas with no issues.

Our fishery opened today so I headed out and everything was working prefect until on the way back in for the day i started to loose a little power. The engine would normally run around 5800 rpm WOT and i would cruise it between 4500-5000. Ever since i can only reach 4500-4800 WOT and it takes a long time to get on plane.

I checked the plugs (which were new two tanks ago anyway) and all three were a nice cardboard brown color or maybe a shade darker. Looked good anyway. But I noticed that the middle cyl plug had a tiny piece chipped out of the ceramic? Tried changing plugs with new ones, still no increase in power. Plugs were QL77JC4 which the dealer reccomended by the way.

I started to wonder if the chipped piece of ceramic could have damaged the cylinder but did a compression test and i got 140 140 130 on three cylinders which seems good. It starts and runs perfect at low speeds and idle.

Anybody have any suggestions on possible things to check? Please help, we only have 3 week recreactional fishery so i'd like to get this thing running right asap. Thanks!

 

[Cofe]

Re: Loss of power... Please help!!!

Are you running ethanol gas?
I would try seafoam in the gas and check fuel lines for air in leaks. Replace hoses that have flat rub wear on the bottom side of hoses caused from vibration.

 

[mikesea]

Re: Loss of power... Please help!!!

Check that the throttle arm is connected to the timerbase under the flywheel OK.It should have a ball and socket attachment on both ends

 

[mmurray70]

Re: Loss of power... Please help!!!

Timerbase is connected and shifting fine. All carbs are opening all the way too. Tried it again tonight and the problem is there right from a cold start.

Im hitting the water again tomorrow. Going to take a timing light and verify timing and confirm spark on other two cylinders too. I was thinking if its a fuel problem it might improve if i try pushing in on the key to add more fuel? Any thoughts? Anything else i should try while im out?

 

[jhcreech]

Re: Loss of power... Please help!!!

hey I had a similar problem with my 90hp evinrude and found that the no.2 cyl was not firing, after diag I found my stator was bad, check and make sure each cyl is firing, a 3cyl is a little diff from my 4 cyl i was able to narrow it down by swapping parts around, power packs etc, but you cant only have one power pack, just see if you have a dead cyl (no fire), possibly low fuel pressure as you are running under a load with the motor acting up try to pump the hand primer to see if rpms come up if it does the fuel pump is bad,

 

[mmurray70]

Re: Loss of power... Please help!!!

I already tried the hand primer with no sign of improvement. Yesterday I tried pushing the key in and adding fuel with the electric primer while running and it improved for a second before it loaded up with fuel. So I realized the problem was somewhere in the carbs.

I took all three carbs apart and found some dirt in the main jet of the middle carb. I really didnt expect the carbs since I cleaned them when I got the motor (less then two tanks ago). And theres a good filter on there. Must have been something in the fuel pump that loosened up and passed into the carbs.

Anyway I put it all back together and seems to work fine again. Thanks for all the suggestions in any case.