Yanmar 3gm30f

[Badsanta]

Dampning plate removal
I know the info is here because I've read it before, but can't find it .

Transmission came right off.
Having trouble removing the dampning spring plate. Unscrewed everything and tapping ring but don't want to pry or break this.

Is there a specific tool or do I just hop on one foot and scrach my head.
Many thanks. Alan

[sailorchic34]

Tap on it gently with a hammer at the hub and try wiggeling it. Mine came right off.

[Badsanta]

I'll try that.
Pistons out. No obvious broken rings or pistons. Some ware on the main bering but the crank looks nice and smooth. I'll have it all measured up at a shop.

[sailorchic34]

Is there a ridge at the top of the cylinders??

[Badsanta]

3 piaton rings and several small thin machined lines around the top of the piston

[Badsanta]

Cylinders

[Badsanta]

The plate came right off with a tap. I couldn't see the seam. Thanks

[sailorchic34]

Hum, there are some light scuffs and scratches on at least one wall.

I would use the sailorchic method of checking cylinder taper. Remove one ring from the top of one piston, gently, and slide it 1", 2" 3" and 4" down each cylinder (useing a pistion to push it down so it's true and right angle to the wall and measure the end gap with a feeler gauge. Ideally the gap should be the same (within 0.001" well really 0.0005, but feeler gauges only go by one thousand)) which means there is little wear on the cylinder walls . IF not the cylinders are tapered and probably should be bored to the first oversize .10 over (0.25mm). Then new pistons and rings, and new bearings on the crank.

Measuring the end gap also will tell if the rings are within the service limit or not.

Note when my piston ring lands broke at 1100 hours there was no appreable wear on the rings (in the good cylinders. New and old measured exactly the same.

You'll want to use plastic gauge to check big end wear too. With 2000 hours its probably not bad at all. I image you would just need new standard bearings.

[Badsanta]

Sounds great. Thanks