Kubota V 1902 engine+

Ivan in Mich · Apr 21, 2022

I have the engine out of my skid steer and am put ting it back togat her. Everything was going fine until I got to the rod bolts. I was careful when I took it apart to mark all the caps to the rod the way they came off. I mi' the crank and standard bears would work. Engine onl;y had less than 3000 hours on it. Now when I put new bearing on it and torqued the caps down in steps and equal on each side the crank will not turn. I checked the box and bearing say std. Could it be the bearing are wrong or what else is it

Steve@Advance · Apr 21, 2022

It's possible the bearings are made wrong, mis boxed, whatever something is seriously wrong! Good that you caught it!

I would check the new rod bearings against the old ones. You can check the thickness with calipers near the ends, there will be little wear there. They should be very close to the same thickness. If the new ones are .005 thicker, they are .010 under and mis marked.

Bad news is if they are the wrong bearings, and the rods were torqued down on them, chances are the rods are now out of tolerance. The safest thing to do would be to have the rods reconditioned and buy another set of bearings from the shop that reconditions the rods.

Other things can cause the lock up though, pistons in backwards, rods in backward, caps reversed or mixed, or debris under the bearings. Whatever the cause, rods are very sensitive to distortion. Not a place to be cutting corners!

RCP · Apr 22, 2022

I assume you installed new piston rings?

I rebuilt an Oliver 77 engine, and as I installed each piston assembly the engine became harder to turn the crankshaft. I tore the engine apart thinking I had done something wrong, I could not find anything and decided it was drag from the piston rings. After the engine ran for a few minutes it was much easier to turn the crankshaft.

DelMN · Apr 22, 2022

Get some plastic gauge and check the clearances. Available at auto parts stores and very inexpensive.

Ivan in Mich · Apr 22, 2022

This is what happened. I took the bearing all off this morning and checked thickness with old ones it was the same. So I cleaned them all up put them in the rod and the cap oiled the bearing surface up and put back togather. This time I rotated crank between lower torque setting t hen went the next step on the torque. When I got to the last one the crank turned hard but it turned. I lubed bed up cyl walls the best I could with oil then rotated the engine again. All is well now thanks for all the help I was pulling my hair out what I have left anyway. Probably invented a few new words in the process

Wheat47 · Apr 22, 2022

I learned (the hard way!!) to turn the crank over after I torqued each of the
main bearing, and each connecting rod/piston as I installed them.
Over the years, I discovered a couple of errors. One or two of them mine
and a few mismarked/mispicked bearings.

Kubota V 1902 engine+

Ivan in Mich

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Steve@Advance

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RCP

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DelMN

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Ivan in Mich

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Wheat47

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