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SeaRAY 100 HP 4 CYL 2 STORKE

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kellog

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I am new to this forum. I need a little help with a 1989 "SeaRay" (Mercury) 100 hp 4 cyl 2 stroke 2+2 engine. First is finding parts.
The engine serial number is 1C102127 which does not pull up as a 100 hp 4 cyl. The SeaRay version of the motor does not have the serial # on the transom bracket. It is only on the welsh plug on the block and only has the last 7 digits. I had to call Merc to find out what the whole serial # was.
They had a record of it tied to my name after 33 years (I bought it new in 1989). I need to get some parts as you might imagine.
When I put the serial number in the Marine Engine.com parts finder I get "Mercury / Mariner (40 Carb 4-Stroke - 3 Cylinder) Engine Components".
Is there a way to get parts info on this engine?
 
Forget the 1 at the front.-----Look the parts up for a 1989 model 100 HP 4 cylinder Mercury.-----Clearly listed.----Solved.
 
I have not run this motor for a few years. The last couple of times ran it, it ran well for a an hour then I could not get more than 2500 rpm out of it.
Now I find that there is no spark on any cylinder. Compression is 120, 100, 120 and 120 psi top to bottom.
Gas tank needs to be emptied/cleaned and the 33 year old gas lines need work badly. Should I put in a filter with water separation when changing gas lines?
Or is that overkill.
Stator blue to blue/white has infinite resistance (not OK). The red to red/white is in spec at 110 ohm. I assume a new stator is needed,right?
Trigger has .82-.83 K-ohm, in spec. While removing the flywheel should I change the trigger anyway (again 33 yrs old)?
As far as removing the flywheel, what is the best way to keep the flywheel stationary while loosening or tightening the nut?
Sorry for all the questions, but I find the people on this forum very knowledgable (as opposed to me) and helpful.
 
The 100 psi compression is a huge concern.----Deal with that first !----Pull exhaust covers and inspect #2 piston.
 
racerone, Took the exhaust plate off and you were right on the money. Smeared aluminum in the body of the piston. Some of it is right over the ring and all the way down to the bottom of the piston. I am trying to attach two pics but I am new to this forum so it might not work for me (operator error).
 

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No surprise to me.----Not a hard repair if you can do it yourself.-----Might be difficult to find a shop willing to help you.-----If a shop is willing then the cost might shock you.
 
racerone said:
No surprise to me.----Not a hard repair if you can do it yourself.-----Might be difficult to find a shop willing to help you.-----If a shop is willing then the cost might shock you.
Click to expand...

If I was going to do it myself it's a complete tear down, new piston, maybe machining or honing the cylinder to clean it up then reassembling the whole engine. Depending on the damage to the Cylinder, would possibly need a slightly oversized piston.
I would think there are shops out there that would clean up the cylinder, right?
Are there many special tools needed to do this job like ring compressors for getting all the pistons in at once, etc.?
When I am finished, I still have a 33 yr old engine that hopefully works until the next thing goes.

Some other options are a buying new engine or used engine ($$$$), maybe buying a re-manufactured short block. Any thoughts on these other options?
Are there any other options?
 
Decided to go for a short block. Picking it up in a week.
I have a couple of questions.
First the short block does not come with all the studs such as carburetor mount studs, studs that pass thru the exhaust plate (mid-section), etc. What is the best way to get the old studs out of the old block?
Second, what is the best way to separate the block from the exhaust plate? When I loosen up the 8 nuts under the Powerhead it doesn't even think about moving.
 
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