Please have a look at the first item in this link:

http://www.aetnaengineering.com/tachometer-senders-sensors.asp

I wonder if anyone could point me towards a supplier of something similar in 
the UK?

It's for a Rolls Royce (Perkins) Eagle engine but I could probably adapt 
anything 1/2 suitable to fit. Too old for most scrapyards nowadays :-(

Cheers Julian.

On 28 Oct, 21:45, "Julian"  wrote:
> Please have a look at the first item in this link:
>
> http://www.aetnaengineering.com/tachometer-senders-sensors.asp
>
> I wonder if anyone could point me towards a supplier of something similar in
> the UK?
>
> It's for a Rolls Royce (Perkins) Eagle engine but I could probably adapt
> anything 1/2 suitable to fit. Too old for most scrapyards nowadays :-(
>
> Cheers Julian.

looks very similar to the rover pg1 gearbox one .

the gearbox is found on the 2 ltr T-sreries and diesel engines  fitted
to 220 420 600 and 800.

all the best.markj

In uk.rec.engines.stationary Julian  wrote:
> Please have a look at the first item in this link:
> 
> http://www.aetnaengineering.com/tachometer-senders-sensors.asp
> 
> I wonder if anyone could point me towards a supplier of something similar in 
> the UK?
> 
> It's for a Rolls Royce (Perkins) Eagle engine but I could probably adapt 
> anything 1/2 suitable to fit. Too old for most scrapyards nowadays :-(

The Eagle was used in a wide range of British trucks including ERF.
Dealers may still have some old stock.

Hi everyone, I'm new to the group and seeking suggestions.
I bought a non-working Allen scythe last year and have begun trying to
get it running to work, rather than enjoy an elegant retirement. I
have stripped and freed the cutter bar, inspected the oscillating
drive mechanism but have found the engine is solid due to the piston
being seized in the cylinder. Also the exhaust valve has corroded off
the end of its stem. These problems are due to it being left under a
hedge for many years with the spark plug missing.
The engine fan casing plate is almost unreadable but towards the top
right hand side is a number 25T which I think must indicate it to be a
mk 25 stationary engine mounted to the machine via a flange on the
shaft outlet plate.
Having been watching ebay for a while and not seeing anything on the
lines of valves or pistons I chanced across this group and wondered if
anyone has suggestions for (a) getting the piston out and (b) sourcing
a valve?

John

cynic wrote:
> Hi everyone, I'm new to the group and seeking suggestions.
> I bought a non-working Allen scythe last year and have begun trying to
> get it running to work, rather than enjoy an elegant retirement. I
> have stripped and freed the cutter bar, inspected the oscillating
> drive mechanism but have found the engine is solid due to the piston
> being seized in the cylinder. Also the exhaust valve has corroded off
> the end of its stem. These problems are due to it being left under a
> hedge for many years with the spark plug missing.
> The engine fan casing plate is almost unreadable but towards the top
> right hand side is a number 25T which I think must indicate it to be a
> mk 25 stationary engine mounted to the machine via a flange on the
> shaft outlet plate.
> Having been watching ebay for a while and not seeing anything on the
> lines of valves or pistons I chanced across this group and wondered if
> anyone has suggestions for (a) getting the piston out and (b) sourcing
> a valve?
> 
> John

Meetens <http://www.meetens.co.uk/> do a lot of Villiers parts and could 
probably help. However, if it is that far gone, you'd probably be better 
off looking for a complete running MK25 (not uncommon) either on ebay or 
at the sales (Enstone coming up soon). You should then be able to swap 
any special bits (mountings, couplings etc) for the Allen Scythe 
application over to the 'new' engine and be up and running for probably 
less cost and less effort.

NHH

On Thu, 29 Oct 2009 12:28:26 +0000, NHH wrote:

> However, if it is that far gone, you'd probably be better off looking 
> for a complete running MK25 (not uncommon) 

That is a option depends "how far gone" it is. Taking the head off
and looking at the damage is the next step I feel and possibly the
sump/crank covers to see what it's like down there. If it doesn't
look too bad, filling the pot with diesel and leaving it for a week,
a few gentle taps onto a mandrel just slighly smaller than the bore,
more diesel and waiting and repeating might free the piston. Removal
of crank is probably adviseable so you know that the only thing
stopping the piston moving is the corrsion between it and bore.

-- 
Cheers
Dave.

cynic wrote:
> Hi everyone, I'm new to the group and seeking suggestions.
> I bought a non-working Allen scythe last year and have begun trying to
> get it running to work, rather than enjoy an elegant retirement. I
> have stripped and freed the cutter bar, inspected the oscillating
> drive mechanism but have found the engine is solid due to the piston
> being seized in the cylinder. Also the exhaust valve has corroded off
> the end of its stem. These problems are due to it being left under a
> hedge for many years with the spark plug missing.
> The engine fan casing plate is almost unreadable but towards the top
> right hand side is a number 25T which I think must indicate it to be a
> mk 25 stationary engine mounted to the machine via a flange on the
> shaft outlet plate.
> Having been watching ebay for a while and not seeing anything on the
> lines of valves or pistons I chanced across this group and wondered if
> anyone has suggestions for (a) getting the piston out and (b) sourcing
> a valve?

This link might be useful: http://www.vintagemotorcyclepistons.co.uk/

Hmmm, have you got the head off yet? If  so, what treatments have you tried? 
We can offer you all sorts of ideas once we know how far along you are!

Regards,

Kim Siddorn

Dave Liquorice wrote (snip):
> On Thu, 29 Oct 2009 12:28:26 +0000, NHH wrote:
> 
>> However, if it is that far gone, you'd probably be better off looking 
>> for a complete running MK25 (not uncommon) 
> 
> That is a option depends "how far gone" it is. 

I tend to think that if it has got to the point of rusting the head off 
of the exhaust valve, then it is pretty far gone!

NHH

On 29 Oct, 19:04, "kimsiddorn"  wrote:
> Hmmm, have you got the head off yet? If  so, what treatments have you tried?
> We can offer you all sorts of ideas once we know how far along you are!
>
> Regards,
>
> Kim Siddorn

I have removed the engine from the machine, taken the head off and
poured light oil into the pot. When I started the piston was about
1/8" below the top of the cylinder.  I have tapped the piston down
using a steel pipe with a square end only a little less than the
diameter of the bore and managed to move the piston down about an inch
over a number of weeks resting and re-oiling by degrees. I have had
the cylinder holding down nuts off and the crank rotates freely within
the limits of piston movement and the cam followers move in
synchronism with the crank while the cylinder block moves up and down.
Basically the piston has reached a point where it is jammed where it
is and I cant get to the underside to tap it back up again.
Maybe the suggestion of simply swapping the whole engine is the best
way forward in the circumstances. I am watching ebay and have seen a
couple of other types of machinery with the same engine so if
something goes for a low money bid I will follow that route and
hopefully have the same shaft end to deal with. In the meantime I will
keep applying penetrating oil and percussion.

cynic wrote:
> On 29 Oct, 19:04, "kimsiddorn"  wrote:
>> Hmmm, have you got the head off yet? If  so, what treatments have you tried?
>> We can offer you all sorts of ideas once we know how far along you are!
>>
>> Regards,
>>
>> Kim Siddorn
> 
> I have removed the engine from the machine, taken the head off and
> poured light oil into the pot. When I started the piston was about
> 1/8" below the top of the cylinder.  I have tapped the piston down
> using a steel pipe with a square end only a little less than the
> diameter of the bore and managed to move the piston down about an inch
> over a number of weeks resting and re-oiling by degrees. I have had
> the cylinder holding down nuts off and the crank rotates freely within
> the limits of piston movement and the cam followers move in
> synchronism with the crank while the cylinder block moves up and down.
> Basically the piston has reached a point where it is jammed where it
> is and I cant get to the underside to tap it back up again.
> Maybe the suggestion of simply swapping the whole engine is the best
> way forward in the circumstances. I am watching ebay and have seen a
> couple of other types of machinery with the same engine so if
> something goes for a low money bid I will follow that route and
> hopefully have the same shaft end to deal with. In the meantime I will
> keep applying penetrating oil and percussion.

Try putting a couple of stout wooden blocks between the cylinder and 
crank case and see if the piston will continue its downward travel with 
a little further 'persuasion'.

NHH

On 31 Oct, 15:44, NHH  wrote:
> cynic wrote:
> > On 29 Oct, 19:04, "kimsiddorn"  wrote:
> >> Hmmm, have you got the head off yet? If  so, what treatments have you tried?
> >> We can offer you all sorts of ideas once we know how far along you are> >> Regards,
>
> >> Kim Siddorn
>
> > I have removed the engine from the machine, taken the head off and
> > poured light oil into the pot. When I started the piston was about
> > 1/8" below the top of the cylinder.  I have tapped the piston down
> > using a steel pipe with a square end only a little less than the
> > diameter of the bore and managed to move the piston down about an inch
> > over a number of weeks resting and re-oiling by degrees. I have had
> > the cylinder holding down nuts off and the crank rotates freely within
> > the limits of piston movement and the cam followers move in
> > synchronism with the crank while the cylinder block moves up and down.
> > Basically the piston has reached a point where it is jammed where it
> > is and I cant get to the underside to tap it back up again.
> > Maybe the suggestion of simply swapping the whole engine is the best
> > way forward in the circumstances. I am watching ebay and have seen a
> > couple of other types of machinery with the same engine so if
> > something goes for a low money bid I will follow that route and
> > hopefully have the same shaft end to deal with. In the meantime I will
> > keep applying penetrating oil and percussion.
>
> Try putting a couple of stout wooden blocks between the cylinder and
> crank case and see if the piston will continue its downward travel with
> a little further 'persuasion'.
>
> NHH- Hide quoted text -
>
> - Show quoted text -

I can try that but I think the crank is at about 90 degrees from TDC
at present so I wonder why it would make any diference?

By judicious use of wooden blocks, you  can move the piston further down the 
bore & eventually free it off. If it has moved this far, it will almost 
certainly go the rest of the way!

Heat the barrel with a gas torch too - every little helps.

Once off & the bore cleaned up with wet & dry, you might well be surprised 
to find how little corrosion has taken place. Heat cycling the piston will 
eventually free off the rings and away you go.

Regards,

Kim Siddorn

cynic wrote:
> On 31 Oct, 15:44, NHH  wrote:

>> Try putting a couple of stout wooden blocks between the cylinder and
>> crank case and see if the piston will continue its downward travel with
>> a little further 'persuasion'.
>>
>> NHH- Hide quoted text -
>>
>> - Show quoted text -
> 
> I can try that but I think the crank is at about 90 degrees from TDC
> at present so I wonder why it would make any diference?

I see, I thought you had run out of travel. Well, unless there is 
significant corrosion below the point at which the piston has stuck 
(unlikely), then it 'should' continue to move down with successive 
rounds of soaking and drifting.

NHH