1991 Evinrude E15RLEIA Low Compression

[Force 120]

My 1991 15Hp Evinrude has top cylinder 65-70psi and bottom cylinder 90 psi. I remove the head and inspect the cylinder, there is long mark on top cylinder so it explains why top cylinder has a low compression reading. So I decide to give it quick rebuild. Here is my plan: get a good used block and put a new piston ring on old pistons. I find a good block on Ebay but it is not complete (Cylinder block). My question is that could I use other my intake side to mate with this cylinder block. Or it has to be manufacture as a complete block.
As the seller says in the description: cylinder side of powerhead, As pictured, Cylinders in good condition wouldn't hurt to hone them!

 

[racerone]

You need both parts of the block.-----And putting new rings on an old piston is a bad , bad idea.

 

[Force 120]

You need both parts of the block.-----And putting new rings on an old piston is a bad , bad idea.

So what is your suggestion? Put a new piston and new ring? The problem is that is is hard to swap the piston rod to new piston

You need both parts of the block.-----And putting new rings on an old piston is a bad , bad idea.

I appreciate your input: I see a couple well know youtube channels, they just put new rings on the good used piston and hone the cylinders out.
Option #1: could I get a new piston, new rings and hone the cylinder out or go with the option #2:
Option 2: a used 1990 powerhead with 120 psi/120psi and swap it and call for a day. $128.00 + $40 shipping = $168. This road may be easy and smoother way.

 

[racerone]

Not all of the U-tube presenters have good qualifications !!----Putting a new ring on on old piston is a mistake.----Simple as that.-----Why would it be hard to swap the rod to a new piston ??-----Done it many times myself and nothing to it.----Oh, and I have looked at the ring grooves on these under a microscope.----That is why I say it is a mistake !

 

[Force 120]

Not all of the U-tube presenters have good qualifications !!----Putting a new ring on on old piston is a mistake.----Simple as that.-----Why would it be hard to swap the rod to a new piston ??-----Done it many times myself and nothing to it.----Oh, and I have looked at the ring grooves on these under a microscope.----That is why I say it is a mistake !

Watching the internet disencourage me (Amature) to go this proceedure. Since I needs a fixture to press the pin out of the old piston and to press it in a new piston (a chance to distort the new piston). Also the piston needs to be pre-heated up to what temp??? and the pin need to be frozen at the same time. I sketch a design of the fixture (wood or nylon) for 2.188" piston size. The fixture will be bored out to 2.200" to support the piston. Or could I make exact the piston size (2.190")so it will be fully supported without distortion.

 

[Force 120]

Watching the internet disencourage me (Amature) to go this proceedure. Since I needs a fixture to press the pin out of the old piston and to press it in a new piston (a chance to distort the new piston). Also the piston needs to be pre-heated up to what temp??? and the pin need to be frozen at the same time. I sketch a design of the fixture (wood or nylon) for 2.188" piston size. The fixture will be bored out to 2.200" to support the piston. Or could I make exact the piston size (2.190")so it will be fully supported without distortion.

 

[racerone]

How do you know that you need a press with your piston and rod.----But good luck with your project.----I step aside.

 

[airshot]

Just find another used motor in better condition, lots of 15 hp motors out there. If you do an economy repair you will end up with a motor with a short life and have to do this again soon.