# Kohler K181RS, 8 hp engine



## oaked (Feb 25, 2009)

Hi--Some creative thinking needed:

I inherited this Kohler engine which was originally equipped with a gear reduction box. At some point the gear box had been discarded, leaving a standard 2" long crankshaft with spiral, spline gear grooves in the last 3/4" of the shaft. Proceeding back from the grooves to the engine, the crank has a 5/32" wide by 5/32" u-groove circling the shaft. After this the remaining inch or so of crankshaft is simply unmodified round crank.

Problem is I would like to use this engine in a concrete saw which requires a pulley be mounted on the crankshaft--but how to mount the pulley with no key slot. 

One person advised mounting the pulley over the v-groove and winding the pulley's set screw tightly into the groove. Easy to do, but vibration and load torque might well overcome the set screw's ability to hold the pulley to the shaft.

The same guy then suggested drilling and tapping the crankshaft for a long set screw that would seat well into the crankshaft. This sounded possible but I'm not a machinist and don't know how to accurately drill such a hole with a hand-held drill nor what quality drill bit would be required to drill into a hardened crankshaft. (I have a drill press but it wouldn't be possible to position the crankshaft while it was in the engine.) 

Another guy suggested simply using hi-strength epoxy to glue the pulley to the crank. The epoxy would flow into the spiral gear grooves and form multiple T-type connections with the pulley. Having had some experience trying to remove rusted-on pulleys and other devices from round shafts, this seemed to have some merit. But it would also be a migraine of a cleanup if it failed.

Still another person suggested cutting key groove into the spline area. This would be weakened by the empty groove channels of the spline. I also don't know of any way to machine such a key slot while the crank is still in the engine. Although this engine runs well, it is too old to spend a major bucks on machining so I need a thrifty, sturdy, and creative way to mate this pulley to the crankshaft.

Don't spend a lot of time mulling over whether your idea is foolproof, just post it. Even if it is raw, some other person may have a tweak that will make it workable. Thanks for your help.

Jim in Oakland CA


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## bgbass (Jan 11, 2008)

weld the pully on if you go to a good welder he could do a good job


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## Maytag (Dec 10, 2007)

Mill a key slot using a Dremel tool with those carborundum cutting discs. Just take your time and keep the cutting wheel parallel to the center line of the shaft and the tool handle perpendicular to the shaft. Nothing fancy, just measure twice and grind once. Keep the walls of the keyway square and only far enough apart for the key (obviously). Trick--Double up the grinding discs on the dremel bit. They'll last a little longer (less prone to shattering) and cut more groove per pass. If your hardware store stocks them Dremel also makes a thick cutting disc for the same purpose, but you can't always find them.

Hope this helps.

Next idea - anyone- Bueler, ..........Bueler, .........anybody.............

>Maytag


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## 34 terraplane (May 3, 2010)

Hello, I found that using a cheep socket say a 17 or 18 millameter that will fit over the spline with three set screws drilled into it works fine. You can weld any pully you want to the socket. good luck


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