1982 Evinrude 75 HP need some help

[Ryan0186]

I have a 1982 Evinrude 75 HP. Motor has power T/T. It is mounted to the back of my 1978 Mckee Craft Cat Cay. The motor has run well the last few times that I took it out. Throtled up nicely and ran at WOT wihtout any problems. When I took the boat out on Sunday I noticed that when I push the throttle to WOT, the motor boggs down and stays at about 2000 RPMS, very slowly it will reach around 2500 to 2700 Rpms, once here it must hit its power band buecasue the motor will fly at WOT but sounds like it is having a small hiccup every few seconds untill you back off the throttle just a bit. When we were coming back to the landing, fighting against the current and the wind, the throttle was pushed all the way to WOT but would not reach powerband and stayed at 1800 to 2000 RPMs, motor seemed like it had no power. When I got home and was flushing the engine I noticed what looked like oil/gas mix that was leaking out of the bottom on the carbs and leaking down the outside of the lower casing. Think brown oil mix. Is this a carb issue? I have never cleaned them since I bouth the boat last year. rebuild carbs is no problem for me as I have cleaned/rebuilt many O/B carbs before, but if it is something else it might have to be taken to the shop.

 

[Daviet]

Re: 1982 Evinrude 75 HP need some help

Start with the easy checks first, compression and spark, then move on to the fuel delivery system.

 

[clemsonfor]

Re: 1982 Evinrude 75 HP need some help

Im thinking your dropping a cyl and not getting spark somewhre. Check that but easiest will be to duplicate the problem and try and spray fuel in the carbs to see if it helps or puping the ball. If it does you know fuel is the problem.

 

[RZR2007]

Re: 1982 Evinrude 75 HP need some help

Sounds to me like your dropping a cyl. as well, especially only pulling 1800-2000rpms wide open. I lost 2 on my v4 last weekend due to my own stupidity! And that's all the RPM's it would pull at WOT as well. I was able to fix is real quick. Put the muffs on it, run it for a bit then pull your plugs, see if you don't have a wet one or 2, you can also pull the wires off 1 at a time to see if the motor changes RPM. Or get a cheap spark tester and see if you have good spark...

 

[Ryan0186]

Re: 1982 Evinrude 75 HP need some help

Well I took the carbs off and cleaned them. All looked clean and new as if the previous owner had just cleaned them up before selling it. I was looking at the choke butterflies and noticed that even at wot they were only half way open. I adjusted them to open all the way up at WOT and now the motor feels like it has the power it needs to go. I must have been chocking it down at WOT. Looks like that must have been the problem. Also pulled all the spark plugs and they were oily now wet. Cleaned them up. Im gonna go outside in a bit and do the spark plug test that yall were talking about.