Help crank question k241
 

I'm doing an engine swap on my '64 Cub 100. Both motors are K241 10hp Kohlers but upon swapping the good parts to the new engine, I noticed the way the flywheel screen/drive coupler attaches to the crank are different. The original attaches via a bolt in the center of the crankshaft and the new engine has a threaded crank on the outside only. What should I do??

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You will need the correct drive cup for that application.

Are they different for the bolt style vs the nut style? What is the difference?

The bolt hole in the drive cup is smaller.

Can't you just drill it out?

If you have the one from the other engine and the hole is the same size as the bolt then use it.

Try talking to Mid West Super Cub (https://mwsc.co/ ). They have an adapter that should fix your problem.

link to there catalog:
https://cdn.shopify.com/s/files/1/18...72684240155565

Go to page 14-right side-item 51168 SW.



The Magnum crank has a bolt on the crank end to hold the hub on. I have repaired a few cranks that broke the threaded end off by drilling a hole, threading it and used a bolt.

My guess is either you have a magnum crank or the threaded end was broken off.

not just the Magnum cranks had the bolt, many K series did too before Magnums came out/

and as a side note, back before Kohler screwed up their corporate website, I went on their parts section ("many times") and at one time, I was looking at many of the cranks they listed, was doing a similar "build 1 good engine outta 2" thing, and believe it or not there are many Ks and Magnums that actually took the same part number of a crank as each other.
The nut or bolt flywheel retainer setup is NOT A "K series crank" vs a Magnum series crank" sort of thing..... I work on a lot more K's than Magnums and on most, I don't have to go "that" deep into to get running, it seems I see more K's with the bolt than I do with the big nut holding the flywheel in place.

the new cranks have had the bolt for about 20 yrs. and they come with the bolt ,thick flat washer, lock washer and a bushing to fill the 5/8" hole so the 3/8" bolt fits good

Does anyone happen to have a diagram of the parts required mentioned above? I’ve encountered a similar issue on a k301 I bought to replace a 241 .