Kohler K91

[Red Headed Horse 38]

I have potentially been offered this Kohler k91 engine. Would this be suitable for a WH 400 Suburban?  From the serial # can anyone tell me what year it was made? Thanks 

[clueless 2,898]

What does the PTO side shaft look like?

 

[Red Headed Horse 38]

[Red Headed Horse 38]

These are the only photos I have of the engine. It is on a Oxford Allen Scythe finger bar mower.

[formariz 11,849]

It will work on the 400 assuming it has the correct Shaft on the opposite side which there are no photos of. However I would be reluctant about it seeing it apart like that. Obviously the flywheel was removed. Perhaps it lost spark? If you don't know for a fact that it does work I suggest you stay away from it unless its free.

[SPINJIM 1,978]

From your description of the equipment it came from, there is a good chance that it has a gear reduction housing on the PTO side.  If you remove the gear reduction, you have a SPLINED output shaft which doesn't work easily with pulley.    From the looks of it, I'd avoid it.

   Jim

[Red Headed Horse 38]

3 hours ago, formariz said:

It will work on the 400 assuming it has the correct Shaft on the opposite side which there are no photos of. However I would be reluctant about it seeing it apart like that. Obviously the flywheel was removed. Perhaps it lost spark? If you don't know for a fact that it does work I suggest you stay away from it unless its free.

 

Apparently it does runs though it is was smoking!  He had cleaned the points etc and had a weak spark but managed to get it running,

 

57 minutes ago, SPINJIM said:

From your description of the equipment it came from, there is a good chance that it has a gear reduction housing on the PTO side.  If you remove the gear reduction, you have a SPLINED output shaft which doesn't work easily with pulley.    From the looks of it, I'd avoid it.

   Jim

 

I have asked him for more photos and information.

 

Thanks both of you to responding; much appreciated.

 

[gwest_ca-(File Mod) 10,478]

The 635106x should have 7 digits. If that is so Kohler made it in 1974.

 

K91-PT

P suffix is for a pump

T suffix is retractable starter

 

https://www.partstree.com/models/k91-31934-kohler-k-series-engine-made-for-hancox-4hp-3kw/

 

Garry

[wallfish 15,905]

Being in the UK means you guys have a much harder time finding these engines than we do here in the US. If it's running with a weak spark it's most likely the condenser and or the points gap. If the price is fair to you, then I'd say go for it. Even if it has the gear reduction gear teeth on the shaft or a tapered shaft. If you have some mechanical abilities, the teeth can be ground off to fit a pulley, an adapter for a tapered to straight shaft or the whole crank shaft changed. With it smoking, you might need to rebuild so changing the crank shaft would be best if necessary during a rebuild.

 

At the big show a couple of years ago, Charlie the Clinton engine guy showed us the nasty rusted and scored cylinder walls in an old Clinton engine. He did an experiment with installing chrome rings and those were the only thing he did besides wiping the cylinder bore with a rag. When assembled he started the engine and it smoked like a chimney! White oil smoke pouring out like crazy. He left the engine running for a long while and the next day he sold that non smoking running engine. I've read in the past about doing that with chrome rings but this was absolute proof it would work. It's certainly not the better solution compared to a complete rebuild but I'd have no problem doing it for an old tractor engine that only runs once or twice a year to bring it to a tractor show. My tractors are not "restored" either so my comfort level may differ from others. I'd suggest changing the oil often or filtering it often during the process.  

[Red Headed Horse 38]

6 hours ago, gwest_ca said:

The 635106x should have 7 digits. If that is so Kohler made it in 1974.

 

K91-PT

P suffix is for a pump

T suffix is retractable starter

 

https://www.partstree.com/models/k91-31934-kohler-k-series-engine-made-for-hancox-4hp-3kw/

 

Garry

 

Thanks Gary, great to know thevengine age etc.

 

4 hours ago, wallfish said:

Being in the UK means you guys have a much harder time finding these engines than we do here in the US. If it's running with a weak spark it's most likely the condenser and or the points gap. If the price is fair to you, then I'd say go for it. Even if it has the gear reduction gear teeth on the shaft or a tapered shaft. If you have some mechanical abilities, the teeth can be ground off to fit a pulley, an adapter for a tapered to straight shaft or the whole crank shaft changed. With it smoking, you might need to rebuild so changing the crank shaft would be best if necessary during a rebuild.

 

At the big show a couple of years ago, Charlie the Clinton engine guy showed us the nasty rusted and scored cylinder walls in an old Clinton engine. He did an experiment with installing chrome rings and those were the only thing he did besides wiping the cylinder bore with a rag. When assembled he started the engine and it smoked like a chimney! White oil smoke pouring out like crazy. He left the engine running for a long while and the next day he sold that non smoking running engine. I've read in the past about doing that with chrome rings but this was absolute proof it would work. It's certainly not the better solution compared to a complete rebuild but I'd have no problem doing it for an old tractor engine that only runs once or twice a year to bring it to a tractor show. My tractors are not "restored" either so my comfort level may differ from others. I'd suggest changing the oil often or filtering it often during the process.  

 

Thanks Wallfish. As you say these engines are not easy to come by and my feelings are similar to yours in that the engine is ok for occasional use. The guy is on MOM and I saw his post on my wanted thread but as yet nothing have come of it. I have a few other tenuous links to follow up. 

[Red Headed Horse 38]

I hope to receive a K91 engine within the next few days. It was from a fellow WH owner here in the U.K. and I am led to believe it is off a WH. It will need some work on it but it's complete which is the main thing. I will post photos of it when it arrives. 

[Red Headed Horse 38]

Today I got the K91 this morning. Photos to follow at some point.

 

Here are some details.

 

Model No & Serial No T B 138293

 

Spec No. 31776B

 

 

[gwest_ca-(File Mod) 10,478]

Parts list

 

https://www.partstree.com/models/k91-31776-kohler-k-series-engine-made-for-howard-rotavator-4hp-3kw

[Red Headed Horse 38]

13 hours ago, gwest_ca said:

Parts list

 

https://www.partstree.com/models/k91-31776-kohler-k-series-engine-made-for-howard-rotavator-4hp-3kw

 

Thanks for the parts link.