1950-51 evirude 7 or 7.5

[olla12]

A friend of mine just gave me this old engine his dad used to have. It was laying in the barn on some straw up in the loft, it was filthy dirty but after I cleaned it off I discover the motor was cosmeticly perfect from top to bottom. After bringing it home I set on a stand I had and tried to pull the crank opps would not turn, I looked around to see if it had any overheating marks on the outer sasings but found none it was perfect. I would hate to scrap this engine as it looks like it would make a beautiful running antique piece for my old 12ft ceder strip.. Can anyone suggest how to unjam this beauty, so far I removed the spark plug and poured some diesel fuel into the cylinder and placed the engine in such a way that the fuel stayed on top of the piston then I will start and try to rotate the flywheel very slowly. What els mmmmmmmmmmmmmmm

 

[boobie]

Re: 1950-51 evirude 7 or 7.5

You could try Dextron II Atf mixed 50-50 with Acetone. Then a lot of patience. Get a strap wrench and rock the flywheel back and forth regularly every day. BRP engine tuner may also help you.

 

[learningasIgo]

Re: 1950-51 evirude 7 or 7.5

I had the exact same thing with a 1956 Johnson 15 hp. I fille up the cylinders (as much as possible) with PB Blaster and let it sit for a couple of days. The I pulled the head and used wooden block and hammer and tapped LIGHTLY on the pistons alternating back and forth and trying to lightly rock the flywheel between each time of tapping. Keep in mind that the tapping is NOT FOR "DRIVING" THE PISTON FREE!!! You simply want to create some vibration to loosen the rings whatever is causing them to stick (if you are lucky like me and that is what it is). In my case it only took about 5 minutes and it was loose. The culprit?? Old gas had varnished and cause the rings to stick to the cylinder walls. Once it freed up, it was totally free and smooth. Had no dammage whatsoever to the motor and it now runs just fine.

If some of the other "chemicals" don't work, you could always use a little seafoam as well. It is a miracle worker at times. Any case, don't give up on her and be patient when trying to free it up. Most likely, it's not damaged or your friend probably would have know about it. You'll probably have a great motor once you get done with it.

What's the model number? Maybe some of the guys can help you identify the year and hp correctly.

 

[olla12]

Re: 1950-51 evirude 7 or 7.5

Thanks guys, she so nice I hate to throw it out, this am getting some moovement took the head off and a slight tapping on the pistons is working used acetone and atf fluid will keep you guys posted, anybody know where i could get some copies of parts and serv manual.

 

[olla12]

Re: 1950-51 evirude 7 or 7.5

thanks for the info. i let her soak a few taps on the pistons and she as free as a bird, cyl. look great cleaned her up and reinstalled the head cant wait to get her buzzing

 

[steelespike]

Re: 1950-51 evirude 7 or 7.5

I'm pretty sure you can get reprint factory manuals right here at iboats.
If you get us the model number probably on the mounting bracket we can probably
pinpoint the year and model.

 

[1946Zephyr]

Re: 1950-51 evirude 7 or 7.5

That would be a 7.5hp. Cool little motors. You'll have to post some pics. Most likely, You will need to replace the impeller and it's likely, the ignition system will need a once over. 1951 was the model year they changed the ignition to the universal type which they used in the later motors. The good thing is, parts will be always available. Bad thing is, it's likely to deteriorate from sitting, than the earlier ignition system. Those are available at your local marine supply, but for your impeller, you may want to try Sea-Way Marine, or Engine Blade and Prop.

 

[Steve A W]

Re: 1950-51 evirude 7 or 7.5

Here's some sites that deal with "Awakening a sleeping motor"
I learned a lot from these sites .

http://www.precisionservoutboard.com/Information/ArtsFivePointPlan/tabid/65/Default.aspx

http://forums.iboats.com/showthread.php?t=158086

http://www.duckworksmagazine.com/07/columns/max/articles.htm

Good luck with Your motor.
Steve A W

 

[samo_ott]

Re: 1950-51 Evinrude 7.5

Re: 1950-51 Evinrude 7.5

What model # is it? I have several 4443's and they are great lil engines. Good power/weight ratio and an internal tank.

Where's Knowlton? I'm in Chelsea just outside Hull.

 

[learningasIgo]

Re: 1950-51 evirude 7 or 7.5

thanks for the info. i let her soak a few taps on the pistons and she as free as a bird, cyl. look great cleaned her up and reinstalled the head cant wait to get her buzzing

Real glad to hear it worked for you. Just make sure you replace that head gasket. If you choose not too, be real certain it is in good shape and don't forget to check your compression BEFORE you try to start it. That way you can be sure everything is good before you try to run it.

Keep us posted on what you have going on with her and good luck to you!