Gotta pull the Head

[Selkirk_D]

So I’ve pretty much determined that I have to pull the head on my L2850. It’s smoked since I got it and a thermal scan indicates that #1 cylinder is not completing its burn. Reviewing dealer notes revealed that a leak down test showed 70% out the exhaust valve on #1. Valve lash checks out fine. No indication of crack or head gasket leakage into coolant, no coolant loss, no oil loss, no water in oil. Best case, valve seat needs touch up and possibly new valve.

Now for my question: I’m contemplating pulling the pan and replacing rings and rod bearings too, “Just Because”, even though at 2500 hours, the v-1702 runs and sounds fine. Would today’s factory parts be worth the extra price, or are they now Chinese/Indian too? Are aftermarket rings bearings decent quality? Or if all looks good, should I just leave well enough alone and not mess with the Japanese originals?

 

[North Idaho Wolfman]

You haven't done a compression test?
I would do that before anything else, it will give you a baseline on the whole engine.
If you pull the head and there is any damage to the piston or the cylinder it's not always a simple as just replacing parts and if you're in it that far you should do everything.
And yes that require pulling the motor.
Sending it to a machine shop having the sleeves pressed out new ones pressed in and bored to size.
Get a full rebuild kit and throw out the head gasket, use OEM for that.
There are several different V1702's, you need a rebuild kit for a V1702-DI-A
If you get a kit for a V1702-IDI nothing will fit.
The pistons are directional as are the rods and also don't swap them in the cylinder location either, several of these older engines have a different rod in one location.

Kubota parts are better in some cases, but due to the age and price aftermarket will be fine.