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Collection, Preservation and Display of Old Lawn Mowers

Punch 43 clutch removal

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Hello,

I want to remove the centrifugal clutch off the crankshaft (without damaging anything)

I have undone the rear square bolt, its a later torsion spring job, but I see that removing shoes or springs won't achive much.

Are these threaded to the crank at all or a taper that need pulling off?

Safest way to do this without case or crank damage?

Many thanks

 

Forums

hillsider Wed, 29/08/2018

The clutch slides on to a parallel shaft with a steel key located in the key way cut into the Crankshaft and the alloy clutch housing.  You were correct to remove the square headed bolt to release the clutch housing this will often allow the clutch housing to simply pull of of the crankshaft by hand but sometimes a little gentle persuasion may be required to get it moving . If things are really stubborn you can try some gentle heat on the alloy hub to expand it or if you have access to a gear puller give that a try.

While attending to the clutch check that the clutch shoes are free to move on their shafts they are prone to becoming seized and in a severe case will prevent the clutch from engaging correctly.

 

 

Chris G Wed, 29/08/2018

Thanks for the advice Hillsider, it was not doing the simply sliding off that's for sure!

WD for a bit then the heat as advised and managed to get it off square with hands only behind.

Interestingly if you look at the top shoe spring, it was not located correctly so never any pressure on that shoe, I would be surprised if that had dislocated under operation, assume never fitted correctly but you never know?

The clutch will not be going back on, this engine is a bit of a project :-)

wristpin Wed, 29/08/2018

As an aside from your question it’s only just dawned on me that while Ransomes are insistent that their centrifugal clutch shoes are assembled with their free ends trailing those Suffolk/Qualcast ones in your images have the free ends leading.  Not a mistake as they can only be assembled in one manner due to their shape.

On Ransomes machines using centrifugal clutches of a larger diameter, incorrect assembly is possible but results in a snatchy take up of the drive and generally unpleasant handling.  Presumably it’s the smaller diameter of the Suffolk clutches that gives them reasonably user friendly handling.

hillsider Wed, 29/08/2018

That's ok glad to have helped, don't be afraid to post if you have any engine related questions as your project unfolds.

Chris G Thu, 30/08/2018

It maybe just a combination of a larger mower and me getting used to it, but the clutch on the Suffolk 17 is a lot easier to control around the garden than the Marquis 20 - maybe I just need to man up a bit :-)

Chris G Thu, 30/08/2018

I'm pretty sure I will have some questions on the engine. Thanks in advance for that.

I don't know why this motor was laid up, but plug condition was excellent and having stripped and cleaned the carb I did not see any glaring issues there either. Even had a working coil. Compression feels ok but I am going to take the head for a check & valves. I have been toying with the idea of starter handle type affair rather than bolting the cover and recoil back on, but having read a bit I can't see how I'm going to get that to work as the clever bit that would stop the handle putting me in A&E is built into the flywheel systems (or the recoil) not the handles themselves - well not the ones I have seen or read.

Going to make it as pretty as I can, bolt it to a slab of oak and drive I don't know what off it - slow burner pet project :-)

wristpin Thu, 30/08/2018

It maybe just a combination of a larger mower and me getting used to it, but the clutch on the Suffolk 17 is a lot easier to control around the garden than the Marquis 20 - maybe I just need to man up a bit :-)

Not necessarily!. The governed engine , less weight and less momentum  (ok kinetic energy) in the Suffolk's drive is bound to make it easier to handle in a restricted area. A 20" Marquis, as nice as it is, requires a practiced throttle finger and fine judgment of stopping distances.. 

Starters. Settle for what it has, I think that we've had our fill of reinventing the wheel for a while!

Just have a read of this for the time being.

 http://disaster-wise.blogspot.com/2011/08/tales-of-coffman-in-praise-of…

Chris G Thu, 06/09/2018

I have seen that film, never thought about it that way

Not necessarily!. The governed engine , less weight and less momentum  (ok kinetic energy) in the Suffolk's drive is bound to make it easier to handle in a restricted area. A 20" Marquis, as nice as it is, requires a practiced throttle finger and fine judgment of stopping distances.. 

Totally agree & understand that, its fun learning the difference and acquiring the skill !

Starters. Settle for what it has, I think that we've had our fill of reinventing the wheel for a while!

I am begrudgingly throwing the towel in on that..

 

Chris G Thu, 06/09/2018

Before I start cleaning up the motor via soda / sand / glass - not decided yet.

I need to blank off where needed, Any ideas on what size/pitch bolt to get for the exhaust ? OD is about 20mm but I have nothing like that size to compare 

Chris G Thu, 06/09/2018

Would hope to get this all stripped back to bear metal and coat with engine clearcoat 

 

wristpin Fri, 07/09/2018

Before I start cleaning up the motor via soda / sand / glass - not decided yet.

I need to blank off where needed, Any ideas on what size/pitch bolt to get for the exhaust ? OD is about 20mm but I have nothing like that size to compare 

1/2" BSP Tapered, I think.

Chris G Sun, 09/09/2018

Appreciate this thread is getting a bit eclectic  ... 

I noticed the exhaust valve spring on my Marquis sloper engine was a bit off straight, which improved when refitted, but on this A114 they both seem at a really odd angle.

Not sure if the pics are good enough to see, but compare the valve stem to how the springs are - weird! 

Chris G Sun, 09/09/2018

I am going to do the valves and head clean up, not sure if the valve spring angle is something to worry about, they seem to operate fine turning over by hand

NM Sun, 09/09/2018

My Marquis exhaust was the same. Are there not meant to be any retaining cups at the top. If not maybe you could knock some up.

Chris G Sun, 09/09/2018

Nick, Its an idea but fully released the spring maxes out the height of the valve chest, looking at the diags its how it should be and I reckon adding 1 or 2 mm for a locating cup at the top will cause issues, not least in fitment. These valves are fitted with a cotter pin retainer and a breeze for valve removal process, once I got enough lift on the spring I just used a magnet stick thing to slide them out!

I got 0.3 on both which is way higher than should be for IN but not surprised given the amount of crispy bits around the seat and face of IN - book says for IN should be 0.15 and OUT 0.25. Bore and wear looks nice, piston crown looks crispy..

Wrispin, both exhaust and inlet valves are magnetic, so will be using your idea on the the acme electro magnetic solenoid  twizzle stick for lapping :-)

 

wristpin Sun, 09/09/2018

Leaning springs.

If it bothers you just push the springs into line but they will line them selves up after a couple of minutes running.

Chris G Mon, 10/09/2018

Thanks for reassurance WP.

I'm going to start a new thread on making this A114 into a little project.

Not old and a bt off mower topic, but still appreciate all the advice.