Yanmar 3gm piston liner R R

Jim26m

.
Apr 3, 2019
579
Macgregor 26M Mobile AL
Since you didn't specify what aspects of the replacement you needed help with, here are a couple of videos showing small diesel sleeve work. Might give you insight to more specific questions. Glad to see you're still at it!
 

RoyS

.
Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Suggest that you compare your new Yanmar liners to your old. I ordered new liners for my Yanmar 2QM15 a few years ago and discovered a major visible defect in the machining on the new ones. I was able to obtain the design drawing of this part from Yanmar and verify that the machining was in fact defective and outside the design specification dimensions. However, no amount of persuasion effort by me could correct this problem as the machining is done in Japan and no one could or would communicate with them. Supplier drew out tractor equivalent sleeves and they had the same defect. Defect was the depth of the overbore into the cylinder at the top of the liner (not the diameter of the overbore). The depth was visibly lower down in the new cylinder liners than the originals and measurably out of specification. Upper piston ring in my opinion would likely slide into this overbore area with catastrophic results. I finally gave up and returned the defective parts and simply honed my original liners. Also, regarding tractor sleeves; The only difference between the tractor sleeve and the marine sleeve that I could detect was a paint or other coating that was on the outside of the marine sleeve and absent on the tractor sleeve. The 2QM15 was originally salt water cooled and that coating was probably for corrosion protection. My motor rebuild was successful and I enjoyed the project. Good luck.
 
Apr 22, 2011
865
Hunter 27 Pecan Grove, Oriental, NC
Do you have a 3gm or a 3gm30? The 3gm30 does not have cylinder liners.