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Discussion Starter #122
Checking on replacement rings with original supplier.

Now I am worried when cylinder was bored that it was overbored. I do not have access to a cylinder/bore/dial gauge, do any of the parts store lone this out? I really do not feel like dropping $150 on a tool I'll use twice. Anyone in the Nashville area capable of measuring cylinders? All I have is a sliding digital micrometer with "teeth" that are not long enough to "wrap" around the piston or deep enough in the cylinder.
 

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Discussion Starter #123
Bay Area Powersports was nice enough to send over another set of rings to ensure they are the correct set. I cannot find anyone local that is willing to assist in measurements. I want to double check my cylinder bore as well as check the piston to cylinder clearance. Kind of stuck.
 

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Use a .003/.004 feeler guage between piston skirt and bore a .003 should be relatively loose. And a.004 should be snug. These feelers are thin enough to flex to the curve of the bore and be fine. Although it will measure a bit tighter due to curve.

The overbore size should be stamped on the top of the Pistons. It will be marked .25,.50....ext
 

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Discussion Starter #125
Use a .003/.004 feeler guage between piston skirt and bore a .003 should be relatively loose. And a.004 should be snug. These feelers are thin enough to flex to the curve of the bore and be fine. Although it will measure a bit tighter due to curve.

The overbore size should be stamped on the top of the Pistons. It will be marked .25,.50....ext
I know the piston are +1mm (81), I am afraid the cylinders were overbored causing the larger gap in the piston rings BUT I am hopeful the replacement rings fit better.

Do you measure the piston/cylinder gap with the rings on the piston helping it stay centered? And essentially you measure the bottom of the cylinder and the bottom the piston?
 

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Discussion Starter #126
Worked a bit today, seems like good news. I removed the cylinder and piston and measured, sure enough piston skirt to cylinder "skirt" allows the 0.003" and the 0.004" being very snug, 0.005" would not fit. This makes me feel a bit better about the cylinders and I am keeping my fingers crossed the replacement rings will solve my large ring end gap.

Not sure if it matters at all, 3rd picture is the 0.009 feeler inserted between the cylinder wall and the piston wall, not the skirt. Essentially 90 degrees away from the skirt measurement.
 

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You got it. I measure w/o the rings just at the skirt area as you did. The .009 is not as critical. That area is cut away to reduce friction. The piston is centered by the skirts.

The rings are just a mis matched set. Probably for .5 over. It happens every now and then.
 

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Discussion Starter #129
Prepping ski for engine install. I was replacing oil line on my used oil pump. Service manual claims to ensure proper check valve operation, blow through them. I cannot blow through ANY of the valves. Is there anyway to clean them? Maybe "force" open with some compressed air? Trying to avoid the $18/valve, that could add up quick.
 

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Try connecting them up to a can of carb cleaner. That should push through them. It only take a few of pounds to offset them. Just be sure to thoroughly bleed the system. I use my DeWalt 18v impact driver with a 6 point 10mm socket. it fits the pump perfectly. A drill will work though. Turn the pump shaft CCW and open the pump cam or if it's hooked the carbs tie the throttle open. That will help bleed it quicker.
 

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Discussion Starter #131
So you're saying I should be able to blow them open with my mouth? I was able to open them with compressed air but it was a bit more than a few pounds. Even after blowing them out and cleaning with carb clean, I still could not blow through them myself. Five bad check valves seems highly unlikely but possible I guess. I'll go back with my regulator I used on my pop off valves and measure when it opens.

Even worse news, the replacement rings showed up today. I am still getting the same piston ring gap measure of 0.024". The manual calls for 0.012"-0.018" so I am 0.006" too big. So close yet so far.

What is my next option? Trying to find the next size up and filing down rings? How much would 6 thousandths of an inch REALLY affect the motor?
 

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No you won't be able to blow through by mouth. So long as air only goes in the direction of the arrow your good.
I'd call wsm and talk to a costomer service representative. Explain the issue. See if they can help.
Are you using a piston to push the ring in square to a point it's not over any ports. And making your measurements?
 

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Discussion Starter #133
Are you using a piston to push the ring in square to a point it's not over any ports. And making your measurements?
Yeah, I have triple checked everything. Measuring towards the bottom of the cylinder, using the new piston to push it on square. Not over any ports. The ONLY thing I can think of is maybe a shitty set of feeler gauges?

10-4 on the check valves.
 

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How much would 6 thousandths of an inch REALLY affect the motor?

.006 would cause it to have very low compression and a lot of blowby. once they wore in a season or two you'd be doing a new set of rings again.
 

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Discussion Starter #136 (Edited)
WSM has confirmed I received the correct set of rings. So what are my options moving forward? I assume resleeving the cylinders is the easiest option, then have them bored and honed again.
 

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Discussion Starter #137
I sent Big John an email, he bored and hones the cylinders for me. 30+ years as a boat mechanic. I let him know what was going and he fired me back a promising email:

"Don’t worry about the ring being a little big. I see it often and have been asked this question many times. It will run fine this way. Call me if you like."

He doesn't seem to worried about the larger ring gap. I trust his knowledge but at the same time, he's not paying for repairs! Any thoughts, concerns, or opinions?
 

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What type end is on the rings? A blunt end or a stepped end?

Thinking it may be best to order next up ring size and file. But if there a step type end it's difficult. But not impossible 😉.
A Dremel tool, a steady hand to rough cut then a fine file to clean up and fine tune. Just need to keep it clean and square, no burrs.
 

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Discussion Starter #140
Having to replace a PV oil seal and had to buy oil pump gasket. Parts come in first of this/next week depending where your week starts. Its going to be 98 degrees in Nashville on October 1st, I got plenty of time to get back on the water for testing before winterizing.
 
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