89 Evinrude 4 HP 2 stroke overheating - please help

I just bought an Evinrude 89 4 Hp 2 stroke engine model E4RCEC. It seemed to run Ok in the sellers garage in a barrel of water. When I got home I ran it in a bucket with water up to the cavitation plate, and in a few minutes it seemed to be overheating and died. Smoke was coming from the head unit and the screws that hold the cover on were very hot to the touch. (I had earlier sprayed some WD40 on the starter cord recovery spring mechanism and I am sure some dripped down on the engine parts. This could account for some of the smoke.)

I noticed that the water level in the bucket had dropped a bit, maybe 1/2 ?, below the cavitation plate, and that the water intake was up in the underside of the cavitation plate, so with that tiny drop of water level it must have started running dry for a short while. (other engines that I have seen have the intake on the vertical section of the shaft below the plate so a little dip in the water level is no big deal. My bad this time for not noticing!) It looks like the water outflow port is below the water line , no ?pee tube? up above , so watching for water flow seems very difficult.

So can anyone please help me understand a few things. How do I check for adequate water flow on this engine? And was this short over heating enough to cook it? How can I tell if there is damage? How much will these little guys take?

Also, I am assuming that previous owners of this motor have not properly ran the carb dry before storing so the carb is probably gummed up a bit. Short of dis-assembly and cleaning, is there an effective chemical cleaning strategy?

Thanks
kyle

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

You'll need to pull the carb and dismantle to get the jets etc clean. You also need to have the water above the 'bulge' for the impeller, so it's immersed in water when running. Those pumps are not self-priming. Hopefully you didn't cook your impeller.. Good luck!

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

hello, thanks, I was afraid of that. good lesson learned but i guess the impeller should be changed anyway. I will run a compression test to make sure there isnt any deeper damage, then procede.

cheers
kyle

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

There is no need to skimp on the water level. I run mine well up the lower unit way above the pump. You should see a spray of water out the port on the back of the lower unit just below the cowl. These are great motors. Best of luck. Rick.

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

Ok, I am a bit comfused now. I bought a compression tester, admitedly not the most expensive one, but when I tested my engine it showed 30 PSI in both cylinders. (the engine wouldnt start, but i pulled the cord until the guage stopped rising.) I ran the same test on another small OB engine I have and it readx the same 30 PSI. The service manual I have says it should be about 80-100. Are both engines bad, or did I get a dud tester? (please say I got a dud tester...)

thanks
Kyle

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

I'm sure you got a dud. How do you feel now? Better? Seriously, I would be surprised if it's thirty. Did you remove both plugs at the same time for test? Rick.

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

Make sure to screw it in up to the o-ring, but don't tighten it. Also, stay away from those adapters. You don't need them for your motor and they can do damage.

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

FYI I picked another comp tester and got 75 PSI on both cylinders on the Evinrude, and the same 75 on my new Nissan 3.5 that i know is OK. Can anyone tell me if this Is this range I would expoect from these small engines?

thanks
Kyle

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

I have a c. 85 4.5hp Evinrude comp tests at 80-88 lbs depending on which day I test it. Runs very well but is slow to start unless I gap at .040".

Re: 89 Evinrude 4 HP 2 stroke overheating - please help

75 is just fine for your 4HP. I find it surprising you new Nissan is exactly the same though. Just makes you wonder if your new gauge is any more reliable than your old one. I've heard many auto parts stores will lend you a gauge. Perhaps you should try that. Rick.