Petter A Series II - Belt Pulley Gib Key Removal

Once I get my engine starting and running correctly I need to remove both the belt pulley and the flywheel to enable me to remove the flywheel fan casing before the cleaning and repainting works can commence (currently hand painted light green with some strange black and red bits!!).

The gib key on the belt pulley is recessed within the pulley and hence cannot be removed with the curved steel wedge type gib key removal tool.

I have treated the gib key with copious amounts of penetrating fluid over the last week or so and I am currently looking for a method of removing it.

I am currently investigating using a steel cable or chain hooked around the gib key head (bicycle chain will not fit), a piece of stout timber with a hole in it and a scissor type car jack.

However, I would welcome any other suggestions of a simple and cheap solution that might solve this issue.

The belt pulley should have a parallel key not a gib key, once you have loosened the bolt etc. that retains it the pulley should slide off the shaft.

Stuart,

Thank you for your message.

Unfortunately, there is no bolt on my pulley just the gib key.

I would attach a photo if I could work out how to do that!!

David P

Stuart,

Hopefully just found how to host an image (maybe!!).



David P

How I dealt with the same issue David
https://ukengineforum.forumotion.com/t10838-petter-a11-1947-restoration#80400

The cut was made using a 115mm disc cutter, Makita 18volt LXT. Quite an easy job.

Andy,

Thank you for the link - very impressive stuff and a build quality to aspire to.

My engine number is 529244 and it says type A1 on the brass plate (1.5 BHP at 750 RPM).

However, from this engine number I was under the impression it was a Type A Series II.

I noticed that the distance between the magneto points cover and the fan casing is a lot greater on your AII engine. On my A1 it is almost impossible to set the points without removing the magneto.

Is the other engine (the lighter green) you have with the Burgess air cleaner an A1 (my engine has the Burgess air cleaner)?

Regarding the belt pulley gib key removal I will persevere over the weekend with the current 'Heath Robinson' removal system (see photo) with minor adjustments and a bit of club hammer persuasion perhaps.

David P

Andy,

Hopefully the photo will attach this time.

David P

Thank you David.
Good luck with your attempt.

Yes my light green engines are A1's. The Burgess oil bath air cleaner was one of the optional extras at point of order from Petter.

A11 engines usually have a steel timing case and you can also still find these on early A1's as despite Petter making a new aluminium cover they never wasted existing stocks of parts.

A11 A1 basically the same, the clearance regarding the magneto is because the A11 doesn’t use the aluminium interface casting like the A1 but this makes it much harder to fit the magneto without removing the timing cover.

Magneto interface.


A11 Magneto does not use the interface casting

Robotstar5 wrote:The belt pulley should have a parallel key not a gib key, once you have loosened the bolt etc. that retains it the pulley should slide off the shaft.

I think the majority if the Petter A1's I've had came with a pulley with a tapered gib key hammered it.

Broke the chain on my 'Heath Robinson' gib key extractor twice this evening but the modified 'D' shackle around the gib key is still holding up OK.

Will buy a length of stronger chain tomorrow and try again!!

David P

Still trying to extract this stubborn gib key.

Bought a length of stronger chain today and modified the 'Heath Robinson' gib key puller slightly (see photo).

I have tried hammering the pulley on to the shaft with a club hammer as suggested to try and free something up but to no avail yet.

I cannot get the 1.5 tonne scissor jack any further out (without breaking the jack) but maybe in the morning it will have done the business (some hope!!).

Are these gib keys hardered steel or just plain carbon steel as I might have to resort to drilling it in the end to try and collapse the key?

David P

The keys will easily drill out.

Update on gib key issue.

My 'Heath Robinson' gib key pulley did not work with this stubborn key so I resorted to drilling the gib key right through.

Have given it a good soaking again with 'Plus Gas' but may have to apply some heat to get the pulley removed.

On my Petter A, I destroyed the pulley after drilling failed

And there was me thinking that progress was being made!!

It’s very likely that this belt drum had not been off in 77 yrs. All ended well as I wanted a v pulley anyway

I surrender now!!

Just ordered a new disc for the disc cutter from Screwfix and will have to sacrifice the pulley.

Andy,

Not such a precise and tidy removal as yours  - I only have a 4.5" disc cutter so my depth of cut was very limited.

So in the end a combination of disc cutter and club hammer did the job with no damage to the main shaft (see photo).

The annoying bit was the shaft was clean and not corroded and the partially drilled gib key just slid out of the keyway.

So the end of the Belt Pulley gib key removal saga (but flywheel gib key removal next).

The End




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That's a success then