Small Engines (Lawn Mowers, etc.)/Kohler Magnum 20 valve


QUESTION: I have a very expensive lawn machine, a Ransomes Bobcat.  It has a kohler Magnum 20 engine  (mv20).
 I have just tied up a lot of money in this machine, only to find out I cannot get a valve for it.
  The valve is part number 52-016-06-s.  It is the exhaust valve.  

 This machine is only 20 years old,  and already parts are unavailable.
My question is,  since this valve is not available, can you suggest an alternative valve that I can get machined to fit?  
 The valve that was in it is broken at the head.  I am considering seeing if there is a machine shop to  weld it, although I suspect it will not hold even if they can.   

 I am quite despirate, and could get this thing going in a matter of hours except for this part not being available.  
  I suppose that is what I get for buying an american made mower.   It is Kubota for me all the way next time.

ANSWER: I would try a reputable machine shop.  You can ask you local auto parts store but they are usually not much help other than recommending a good machine shop.  If you find a good machine shop I'm betting they can find an old Continental or Wisconsin valve that will fit with a little machining.

Is replacing the engine an option?


---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick response.
 I have already considered these options, and have an engine rebuilders supply place looking for an alternative valve that is close enough I can have it milled to the right size.  
 I am also looking to outright buy a used engine with good valves.
 I don't want to put a new engine on it,  for one thing I am not certain the shafts to other vertical engines are the same size and length,  which is critical.  It is a clutch driven machine.  
 Aside from,  putting the valve in and finishing the job on it is simple and should only take a couple hours to complete.
 And of course, I know this machine inside and out,  and like to stick with what I know.
  Of course as a last resort I might need to.  But I already have a few hundred in this one redoing it,  only to find out Kohler is trying to make their old stuff obsolete.   
 Which, I suspect their psychology will backfire,  most guys I know that use this kind of machinery also know how to work on it, and are likely to switch to other manufacturers rather than having this happen to them.

There are antique engine message boards that could be helpful locating old parts.  The other challenge with parts no longer availabale is the price usually increases as there is no supply but the demand increases.

I had a similar gearbox years ago that busted.  I ended up at the machine shop, as the part was no longer available, and they were able to weld and machine the part to working condition agian.

What is the engine model and spec number?  I'd like to see if I can find the crankshaft specs.


Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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