Low compression Suzuki OB: 105...105.... and 65

TripleJGraffis

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Need your help guys... working on the motor today... compression is 105...105.... and 65 on the top most cylinder. Working on removing the head to check the gasket but I can't get to the 2 bottom bolts with my ratchet. What do I do?
 

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TripleJGraffis

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Never mind. I got it.... head is off. doesn't seem like a gasket issue. Gasket Seems intact. But have a look and advise away.
 

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TripleJGraffis

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Also... last night when I tried starting it up.....I got it to somewhat start and then it died..... it never got to the point where I could stop turning the key and keep it running.... today.... it wasn't as successful. Revelation up a little bit.... stopped and then the starter got hot and started smoking the longer I kept the key turned... so I stopped... funny thing though.... when.I got the head removed....I fired turned the key... knowing the engine wouldn't torn over.... but I wanted to see what the pistons did.... and all of them started moving continuously and without any sputtering or stopping like it did with the head on.... is that normal? Wish I could attach videos on here from my phone.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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this cylinder is toast.
20240409_145146-jpg.396617
 

Scott Danforth

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Why's that? I feel the piston......yes.... but why the cylinder? And what kind of repair am I looking at?
depends on what the bore gauge says. however my guess bore and hone.

how does the bores look where the port are?

the piston is missing parts above the compression ring.
 

kcassells

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Why's that? I feel the piston......yes.... but why the cylinder? And what kind of repair am I looking at?
Gloom Doom is right on the money. Its toast.
"depends on what the bore gauge says. however my guess bore and hone."
All depends on how much $$ you want to spend to bring that ole gal back to life.
 

kcassells

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Also you should go on our outboard website related to your outboard.
Lots of great guys there just for engine help. They got me thru alot of things.
 

TripleJGraffis

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Gloom Doom is right on the money. Its toast.
"depends on what the bore gauge says. however my guess bore and hone."
All depends on how much $$ you want to spend to bring that ole gal back to life.
Not really worried about money but would like to keep it around 1500 or less
 

TripleJGraffis

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depends on what the bore gauge says. however my guess bore and hone.

how does the bores look where the port are?

the piston is missing parts above the compression ring.
I need a bore gauge now? Lol
What is a bore?
What is the port?
What parts is it missing?
 

todhunter

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I need a bore gauge now? Lol
What is a bore?
What is the port?
What parts is it missing?
I agree - that cylinder needs attention. The vertical scratches are why you're losing compression. Also, as Scott said, you're missing part of the piston, possibly due do detonation at some point in the engine's past.

You do not need to buy a bore gauge - you need to disassemble the engine an take the block to a competent machine shop and have them do the work. They will have the bore gauge and other necessary equipment to inspect and repair the block. They will measure the bore (diameter) of the cylinders and if there is enough wall thickness in the cylinders, they can either simply hone out the damage, or bore then hone.

If it only required a hone, you may be able to get away with re-using 2 of your 3 pistons and just re-ring them. If your block requires a bore and hone, you'll have to replace all 3 pistons to go up to the next size. Either way, you'll want to replace the piston with the missing material.

In the pictures below, I've drawn arrows to show you the ports (holes in the cylinder walls - present on 2-stroke engines), and the areas where you are missing part of your piston.
20240409_145140.jpg

20240409_145146.jpg
 

Chris1956

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I doubt those cylinders will clean up with a honing. You might inspect the piston tops to see if they are std size or oversize, as you will likely need oversize pistons and rings, for the machine shop to bore it properly. The real question is how much oversize boring do you need to clean up the cylinder, and are there OS pistons available.
 

cyclops222

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For the pistons and cylinder walls to be that damaged. And that EATEN UP. The attitude was....... Screw the noises. The motor is pushing the boat.
 

racerone

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People often run motors till they go boom.-----The lessons are only taken to heart after the wallet is empty.----And what is the model # of this --" Johnson " ---outboard.-----Johnson is easy to repair.---Other brands may not be.
 

saltchuckmatt

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Jul 19, 2019
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Funny thread really, did you try some "new in a can".

There was a man selling new in a can down in Florida many moons ago. (Fountain of life for you young folks)
 

Faztbullet

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Needs torn down, that cylinder bored and possible the others depend on how they "mike" out size wise. After you fix the result, you need to address the problem as that is preignition, either coil/pack ot timer base problem
 

tphoyt

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Jun 10, 2010
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Just to add my 2 cents. If you don’t know what you’re looking at or looking for I would suggest tearing it down and taking the block to a machine shop to look over everything including the crank and bearing to get the whole picture and an estimated cost.
Jmo
Best of luck
 

TripleJGraffis

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People often run motors till they go boom.-----The lessons are only taken to heart after the wallet is empty.----And what is the model # of this --" Johnson " ---outboard.-----Johnson is easy to repair.---Other brands may not be.
It's not a Johnson. Never was
 
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