K321 came apart!

[oldtin 921 17]

Hi, my K321 balance gears exploded and made a mess inside the block. I removed all the balance gears and trash left behind.  They also broke the rod when they descided to explode. My question is it has the Mahle piston and narrow rod and I want to know if I can put a regular rod and piston in it??Thank you.

[rmaynard 14,911]

First step is to check the spec. number of the engine. Then look at the Kohler parts list, and see if it came with a regular piston. If so, after having the cylinder checked for damage, have it spec'd and get a regular piston and rod to fit. Don't bother replacing the balancing gears when rebuilding.

 

Oh, by the way...

[Fordiesel69 214]

The mahle piston is superior.  Just get the narrow rod.

[Martin 2,130]

make sure the block isnt cracked from all that carnage. common place for them to crack is where the starter bolts on to the block. sometimes a piece of balance gear will get between the crank/rod and get rammed into the side of the crankcase.

 

if there is any evidence of something hitting the inside of the block, i would get it checked.....

 

and 

Edited August 11, 2013 by Martin

[Jeff-C175 7,195]

 

Don't bother replacing the balancing gears when rebuilding.

 

I don't have a K, just curious...

 

I've read before that the balancing gears aren't necessary and should be left out on a rebuild, but wonder why they are in there in the first place?  and if they are not replaced, isn't there more vibration afterward?

[oldredrider 2,547]

IMO...since there is no noticeable difference in vibration with or without the balance gears, they are more trouble than they are worth. I always leave them out when doing a rebuild so I never have to worry about them exploding. Seen many blocks ruined by bad balance gears and their bearings.

Edited August 11, 2013 by oldredrider

[Martin 2,130]

i took them out of the k301 on my c125. dont notice any difference. the engine is iso mounted and runs as smooth as any of the other kohler k singles i have, but without all the vibration.

[oldtin 921 17]

Thanks for all the input. The reason I ask about the regular piston and rod was that the price for the mahle piston and rod is way more than a regular one. I want to replace the piston because there is excessive wear on the wrist pin and where it sets in the piston.