Is this motor too far gone?

[mfw]

So, I picked up this motor. Johnson 1956 7.5 hp motor. I was told the motor was stuck. but I figured since I have 1957 7.5 that I could use the other as a parts engine. Then I got to thinking that I could maybe save this motor. I am new to this hobby and to be honest am pretty clueless. I took the cylnder head off and I found that the top one was all rusty (looks like water got in) and the bottom one was nice a clean. Is this something I attempt to fix or do I part it out? Also, what are the slots at the bottom of the cylnder in the photo. The sea foam just runs right through the slots. THanks. MFW

 

[RogersJetboat454]

Re: Is this motor too far gone?

View attachment 103792View attachment 103793

So, I picked up this motor. Johnson 1956 7.5 hp motor. I was told the motor was stuck. but I figured since I have 1957 7.5 that I could use the other as a parts engine. Then I got to thinking that I could maybe save this motor. I am new to this hobby and to be honest am pretty clueless. I took the cylnder head off and I found that the top one was all rusty (looks like water got in) and the bottom one was nice a clean. Is this something I attempt to fix or do I part it out? Also, what are the slots at the bottom of the cylnder in the photo. The sea foam just runs right through the slots. THanks. MFW

Cylinders may clean up with a hone, and you may be fine with a new set of rings. On the other hand, the cylinders may be pitted, tapered, and the pistons may be junk. Would really need to take this apart to know the whole story. Other issues may be the condition of the crank and bearings. If water found it's way to the crank and bearings, then chances are the bearings are toast, and the crank is pitted. This engine may serve you best as a parts motor.

P.S. The slots on the bottom are the exhaust ports. You may want to go track down a FACTORY service manual, and read up on this motor if you intend to save it.

 

[mfw]

Re: Is this motor too far gone?

Thanks for the feed back. I think I will tear it down. I am hoping to track down another Johnson 7.5hp thats in good shape. I think for the money I would have in this I could by a nice one. Thanks, MFW

 

[JB]

Re: Is this motor too far gone?

There is no such thing as too far gone. The golden wrench goes to guys who restore stuff others won't try.

 

[archcycle]

Re: Is this motor too far gone?

From a hobby perspective, why not? Call it the cost of an education. It's better than learning on the one that's bolted to your boat

 

[mfw]

Re: Is this motor too far gone?

This is true. Looks like I might have a little side project. How would i get that piston un stuck? The seafoam runs out the top cylnder through the exhaust port? Thanks

 

[mark1961]

Re: Is this motor too far gone?

How would i get that piston un stuck? The seafoam runs out the top cylnder through the exhaust port? Thanks

With lubrication (pb blaster/lanox or similar), gentle persuasion and some patience.....some heat probably wouldnt hurt either.

 

[mstahl1171]

Re: Is this motor too far gone?

Spray it with penetrating oil and let it soak over night. Dont worry about the exhaust ports just spray liberal amounts of fluid on the cylinder walls and let it soak. Then take a rubber mallet and gently tap the cylinder and see if you get some movement. Make sure you clean the surface rust off the cylinder walls first before you tap. I used fine steel wool and rags to wipe the walls clean. Just be gentle and you'll get it too break free. You can also apply some heat with a small propane torch to the cylinder wall and then tap. It might take some time but it will break free. I had to do this years ago on my neighbors motor and it worked well, gave a good cleaning afterword. Motor still runs fine after all these years.

 

[nwcove]

Re: Is this motor too far gone?

that top cyl looks kinda scary, but if you can find rings (id love to find rings and hone my dead 56 5.5 out) it can be fixed. its all about being determined to learn.
p.s.....if you find rings.....post back!

 

[mstahl1171]

Re: Is this motor too far gone?

that top cyl looks kinda scary, but if you can find rings (id love to find rings and hone my dead 56 5.5 out) it can be fixed. its all about being determined to learn.
p.s.....if you find rings.....post back!

Call Rick at Fairwinds Marina in Annapolis MD...I bet he has them or knows where to get them

 

[Cofe]

Re: Is this motor too far gone?

May have found you some eye candy on ebay. Check this out...http://cgi.ebay.com/ebaymotors/OMC-...5263279QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

 

[nwcove]

Re: Is this motor too far gone?

that is eye candy! mwf , there is hope!

 

[mfw]

Re: Is this motor too far gone?

I have it soaking in sea foam. I wiped the cyl walls with a towel soaked with sea foam and much of the rust came off. I am going to clean it more tomorrow and add fresh penetrating oil.