On Wednesday, 24 October 2012 18:24:54 UTC+1, Baz wrote:
David Hill wrote in

:





I'm a bit confused about the engine on this one. You say it's a Hatz

diesel, then you say it has a Kohler engine.



He said a Hatz mower. Baz is right see, except it is a petrol engine.

http://www.rescuingthepast.co.uk/Howard_Gem.html



I only know of Kohlers as petrol engines. The Hatz diesel was a 2

stroke diesel engine, and a good one. So I wonder if it's had an

engine transplant at some point, it's often the case with old Gems.

I can tell you a certain amount at least about operation of the Hatz

diesel if in fact that's what it is. The Kohler petrol engines as

fitted to the Gem were pretty much standard industrial engines that

should be self explanatory to anyone experienced with larger petrol

driven garden machines. Try online for facsimile manuals, parts etc.

There used to be a rump of Dowdswell - the company that took over

the brand after Howard went bust and you could get some spares from

them but I don't know if they're still going. A local firm that

serviced our old Gem always seemed to be able to get bits and Gems

are still being used by many landscape firms so you should be OK.



Rod





I don't know if I am missing posts but Baz said it has a Kohler K301T

engine.

No mention of Hatz engine, He also said he has had it running.

I am sure that he can tell the difference between petrol and diesel,

and can tell if the engine has a spark plug or not.



Confusion over I think.

It was bought new with a Kohler petrol engine, as it says on the paperwork,

and was later fitted with the Hatz diesel in the 70's so it could use

cheaper red diesel. I have never heard of any of the two engine

manufacturers before so it's very exciting really. The guy still has the

Kohler engine according to his son and that is mine too, just have to find

it and cart it home. What do you do with this?

I am tempted to restore this beautiful machine, but for now it is a tool

and it runs nicely, a bit rattly.



Baz

No problem, they're both good engines. Go get the Kohler engine, it's well worth keeping and Kohler is still going so spares should be OK.
Am I to take it that you've had the Hatz diesel going? If so you obviously know the procedure for starting etc.
For others who may be interested. The Hatz is a 2 stroke single cylinder air cooled diesel. Starting is slightly different from other more common small diesels in which a decompression lever is flicked over at a strategic point when you are swinging on the handle (you need 3 hands for this)
On the Hatz there is an indexing knob on the side of the engine - fully turned is full decompression and as you swing the engine over the decompression clicks off a click at a time - as small diesels go it's a dream to start.
For cold weather starting there is an L shaped lever in the cylinder head and this can be removed to insert a kind of fibrous 'match' red at the end like an old fashioned match into the end of the plug. This ignites on compression and acts like the 'glow plug' in other engines.
One little quirk which may be disturbing the first time it happens is; if you stall it on a housebrick or such, when you restart it after dislodging the obstruction it may (being a 2 stroke) start backwards and blow the oil out of the oil-bath air cleaner - never mind no harm done, refill the air cleaner and start again, this time all will be normal.
Oh and it runs forever on a tank of red diesel.
The Kohler in the housebrick situation may kick it out and inflict serious pain on your shins - a mate of mine used to wear cricket pads on newbuild sites)

Rod