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Cylinder seal ring?

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ksgoosekillr

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To make a long story short. have a 90 hp 3 cyl mariner. early 90s ODO- serial. Been at a shop the better part of 4 months this time around. Have replaced every single part of the ignition system chasing an rpm limiting issue. Cylinders all have 115-120 psi compression give or take. Fuel system has been ruled out (spraying fuel into carb at WOT does not change rpms.). The last mechanic finally gave up after 4 months, saying it has to be something internal.... Says all elec items DVA and ohm out correct. States there is a noticeable issue with cylinder one and he believes its an internal engine issue and he feels its the "Cylinder seal ring"... now I am very mechanically inclined and have done everything to this engine except tear it completely down. Anyone here care to take a stab at what the heck a cylinder seal ring is? crankshaft seal? Piston ring?

Engine started out being limited to 3K rpms, with some carb tweaks to throttle plates its now 4-4200 rpms. propped correctly, hub not spun. Wont get near the max 5200 rpms needed. Driving me nuts.

compression is done cold and I have not personally verified DVA readings from this last shop. i personally noted a weaker spark in cyl #1 with my gap tester. My next steps are:

tach each individual cylinder to isolate an issue
dva all elec to verify what shop said
run all the tests in CDI and manual on water with engine hot to see if something is present

if the engine had bad rings the compression numbers wouldnt be what they are. but what is a cylinder seal ring? My best guess is a crankshaft seal, but maybe I am missing something here....
 
Remove plates on the side of the block.-----Inspect pistons and rings.----Look for a cylinder sleeve that has rotated.----Cost you for 2 gaskets and you will learn a lot !
 
Remove plates on the side of the block.-----Inspect pistons and rings.----Look for a cylinder sleeve that has rotated.----Cost you for 2 gaskets and you will learn a lot !----Yes there are sealing rings on the crankshaft.----BUT they are between 1 and 2----And 2 and 3 cylinders.------A bad seal ring makes for issues on 2 cylinders.
 
racerone said:
Remove plates on the side of the block.-----Inspect pistons and rings.----Look for a cylinder sleeve that has rotated.----Cost you for 2 gaskets and you will learn a lot !
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remove the exhaust cover and inspect? What leads you to believe a rotated sleeve? I have read several posts i believe from you on this same engine on this forum. I am trying to read any and all rpm limiting issues to learn more about it. So if a sleeve has rotated whats to prevent a new sleeve from doing the same besides pinning it?
 
Found some sealing rings in the '75-78 manual (this is a V6 layout) the only way to inspect them is to remove the crankcase cover.
v6sealing-rings.jpg
 
racerone said:
Remove plates on the side of the block.-----Inspect pistons and rings.----Look for a cylinder sleeve that has rotated.----Cost you for 2 gaskets and you will learn a lot !----Yes there are sealing rings on the crankshaft.----BUT they are between 1 and 2----And 2 and 3 cylinders.------A bad seal ring makes for issues on 2 cylinders.
Click to expand...

are you referring to the bearing roller assemblies between the cylinders on the crank shaft? or the ring that holds the halves together?
 
Some will argue.-----The 3 cylinder does not have seal rings like the V-6 models.-----There are seal rings on the bearing assemblies on the 3 cylinder motor.----There is a spring ring that holds the bearing halves together for assembly.------It is your motor do what you think will fix it.----I have had more than one of these motors apart-------I will step aside.
 
Not a internal issue..if ring bad you will have problems on low end idle also due to cylinders cross-talking. Have the carbs been apart?
 
racerone said:
Some will argue.-----The 3 cylinder does not have seal rings like the V-6 models.-----There are seal rings on the bearing assemblies on the 3 cylinder motor.----There is a spring ring that holds the bearing halves together for assembly.------It is your motor do what you think will fix it.----I have had more than one of these motors apart-------I will step aside.
Click to expand...

I am only picking your brain on this bc of your past experience trying to understand why my symptoms tell some it may be those roller bearing assemblies and why you feel the symptoms indicate a spun sleeve. I plan to remove that exhaust cover and inspect now regardless. I am just trying to learn more. So what happens when the sleeve spins? Exhaust ports become partially blocked? If that was the case wouldnt this become evident on the plugs with a high speed shut down? I plan to swap out the gapless plugs to get a better reading on them but i would think a spun sleeve would show up on the plugs. Just thinking out loud here. So what have you seen on your engines that indicated a spun sleeve was there one sign that really stood out to you?
 
faztbullet said:
Not a internal issue..if ring bad you will have problems on low end idle also due to cylinders cross-talking. Have the carbs been apart?
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i Have personally torn the carbs down 3 separate times. They have had wires thru all orifices' as well as sonic cleaned. Initially when this all started that is what i thought as well. However the fuel system has been eliminated in a couple ways. While at WOT on the water i had the mechanic spray fuel into ea carb throat. If it was being starved the RPMS and sound would have increased. It had no positive effect on the throttle instead causing it too bog down. Another way i know to test this is to use the fuel enrichener to pulse fuel in at WOT, which also caused a bogging situation.

I am beginning to wonder if it doesnt have something to do with that top carb though maybe having a float setting too low allowing it too flood, but then again i figured this would be evident on the plugs.

everything I have been told points to either electrical, or internal. I personally feel like I am dropping a coil at higher speeds as it warms up. It idles smooth, and can push the trailer pretty darn hard in the water in the 3k rpm range. usually this means it will run well on the water, however something is limiting the rpms on my engine.
 
I did not say it is a spun sleeve.-----It is a possibility.------I am not hovering over your shoulder.----Big $$$ has not solved it so trouble shooting might.
 
racerone said:
I did not say it is a spun sleeve.-----It is a possibility.------I am not hovering over your shoulder.----Big $$$ has not solved it so trouble shooting might.
Click to expand...

I have been attempting to troubleshoot this one loner than I care to admit however it doesnt seem the normal issues are jumping out at me or am I am missing them.

When a sleeve does spin, is it apparent at idle?
 
racerone said:
Guessing and installing a bunch of new parts is not considered trouble shooting in my opinion.
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i actually followed both the OEM manual and thy the CDI manual for trouble shooting all the electrical. As well as the carbs, reeds, compression, fuel pump, fuel tanks and venting and I am sure I am leaving out some as well. So before you assume I was guessing, you should go back and read my other posts here with all the previous testing and "guessing" i have done...
 
Well-----The ignition parts that were replaced ( all of them it says ) are very good quality.-----They do not fail at the same time.-----And motor still runs the same,.-----That amounts to the--- " lets replace this " ---and see what happens.----Guessing in my opinion !!!-----Motor still running the same ??
 
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