To hone or not to hone old yanmar

[boden36]

There is a low tech way of measuring big end clearance. A product called ACL Felxigauge ( I just bought some on eBay for next to nothing).
It is a soft plastic strip. You put a little between the bearing and journal and torque the bolts as normal. Then, without rotating the engine, dismantle and measure the width of the squashed plastic against a scale on the side of the pack. Dead simple and pretty accurate. You would need a new set of shells to get a realistic idea of journal wear though.

Regards,

Richard.

[ti325v]

Hello Bowden:
I know about the plastiguage...read the whole thread.... I was the first to bring it to the island, unknown before my arrival..it will tell me journal clearance, but not if the big end is out of round.
Thanks though.

[boden36]

You can use plastigauge to tell out of round, just make a series of new plastiguage measurements with the crank in different degrees of rotation (say 6 o'clock, and 3 o'clock). Keep the plastic in the same orientation to the big end cap each time.
You can also measure taper by checking each end of the plastic.

Regards,
Richard.

[ti325v]

Hello Richard and BobConnie and everybody who offered terrific advice here, I got crazy busy and have not had a chance to close the post and thank everybody.
Richard, you are a clever man great idea there about how to measure out of round for the big ends.
I have in the mean time procured a big enough mic to check the journals and a bore gauge, though an excellent on the spot way to check was proposed by Richard.

Having said that.....I finally have gotten some great service from Yanmar Japan, I needed a clutch and some other bits for the gear box. But...I am stymied by the fact that Yanmar no longer has pistons, liners, rings, valves, springs.....they can make me bearings.....
So I am kind of stuffed...now I am looking at Chinese suppliers for a master rebuild kit.
Thanks everybody for all of your input....The plan is a master rebuild kit, no honing required, new liners, new rings and pistons, valves...effectively a new engine.
I was up in saigon recently after market suppliers told me.
Yup, sure we can match it, but you have to send us up samples.....My though..okay you want me to pull a rod, liner, head, and send them up to you, lay my boat up for a month, so you can hopefully send them back to me with the chance that you cannot in fact match them ?
He proceeded to drop the piston and pin he was showing me onto the concrete floor and put it back in the box !
Oh man.
Thanks again all. I am so grateful for all the help.
Larry