4 hp evinrude hardly any power

[firsttimeboater04]

Hi guys, hoping someone can give me some advice.

I am very new to boating (2 days ago)
I bought my first outboard, a 1969 or 1970 evinrude lightwin 4 hp. Problem is, it won't run over 1/4 throttle when there is a load on it. I know this because I broke the shear pin while testing it and then it revved fine. With a load, it runs barely above idle speed. Sounds good, idles good, and I purchased a new Johnson/Evinrude fuel line and have the correct mix of oil and gas (50:1- 1 pint for 6 gallons) The only time I can get it to rev slightly is with the lean/rich knob all the way to lean.

Before I start tearing everything apart, does anyone know where I should start? The last owner rebuilt a lot of the engine; it has new plugs, new wiring, impeller, etc. Any help would be greatly appreciated. I think it's getting way too much gas, but I'm not sure.

Thanks,
Matt

 

[Rick.]

Re: 4 hp evinrude hardly any power

Sounds like your in need of a carb. cleaning and a new carb. kit. That should smarten it up for you. I wold also suggest getting the correct OMC service manual for your new motor. It gives you lots of good information and procedures. Then when you have a question ask here and lots of help will come. Best of luck. Rick.

 

[CATransplant]

Re: 4 hp evinrude hardly any power

Very likely it's only running on one cylinder. Check the spark on both cylinders. Or, pull one plug wire and try to start it. If it starts, that cylinder is getting spark. If it doesn't, try the other cylinder. The one where it won't start is the one with no spark. If it starts on both, it's something else.

Since it'll start and run, that's an easy test. You should also check compression on the dead cylinder. If it's OK, then it's time to pop the flywheel off an check the coils and points. If one's cracked or there's some other issue, you've found the problem.

Eliminate ignition problems first. Then move on.

 

[firsttimeboater04]

Re: 4 hp evinrude hardly any power

Ok, thanks, good advice from both. I suspect the carb will probably need cleaning as stated. So, as it was said, to test the cylinders I simply remove one spark plug and try to start it, and then reverse plugs to test the other one?

 

[CATransplant]

Re: 4 hp evinrude hardly any power

Yes. Pull one plug wire and try to start. Then replace that plug wire and pull the other one and try again. If it starts on one but not the other, you've found no ignition on the one it didn't start on.

If it starts on both, when tried individually, then the problem is elsewhere. It's a rough test, but it often tells the tale.

 

[firsttimeboater04]

Re: 4 hp evinrude hardly any power

2 more questions and I swear I'll stop bothering everyone.

1. Where will I find a carb kit for this motor? (iboats has carb kits for 4 hp evinrudes back to 1983 only)

2. I read in another post about the lean/rich knob on this engine accidentally bumped out of sync and that you can pull it off and reposition it. Good idea/bad idea? (for a test)

Thank you again.

 

[Rick.]

Re: 4 hp evinrude hardly any power

Your no bother as long as your trying. You should be able to get a kit at any OMC dealer.
http://forums.iboats.com/showthread.php?t=167352
This link is from the Top Secret File at the top of this forum. Lots of good information in that file. Let us know how it goes. Rick.