1955 Model D150 Version 2 - Repainting silencer

[Big Al]

My silencer is the type you can unbolt and dismantle - in theory anyway!
Should this just be degreased and wire brushed before the new black paint is applied, and should it be primed first?

[jbcollier]

High heat paints do not require primer. Get it apart first as it may well be coked up.

[Big Al]

Thanks John.
I will take it apart and give it a good clean out before painting.

[Big Al]

As I feared, the brass nut on the end of the long central rod has seized and refuses to budge, even after soaking with penetrating oil for several days.

It has two flats, and appears not to be the correct part, as my orange covered spare parts catalogue (by Acme Press of Wimbledon) shows a lock nut (or "grub") and a retaining nut (or "bush"), plus a washer, on the rod protruding through the end plate.

It looks as though I will have to use a nut splitter or similar to remove the nut, unless anyone has a better suggestion?

The silencer has what appears to be APPR IGM50315 stamped on the main body, near the larger diameter pipe which fits onto the exhaust stub of the cylinder. Is this the correct part?

[jbcollier]

Any chance you post some photos?

[Big Al]

Hello John
When I try to post a photo, the message comes up: "The file is too big, maximum allowed size is 256 KiB."
All my jpg photos (from my iPhone and my Canon camera) are more than 1MB, so I cannot attach them here.

[jbcollier]

Upload them to free image hosting site and then post the links here.

[Big Al]

Can you recommend one please John?

[jbcollier]

Email them to me and I'll post them. My email is:

j b c o l l i e r at s h a w dot c a

[Big Al]

Thanks John. I have just emailed them to you.

[jbcollier]

https://jbcollier.smugmug.com/Scooter/i-vb8rfkp/A

https://jbcollier.smugmug.com/Scooter/i-GLbzfTT/A

https://jbcollier.smugmug.com/Scooter/i-RsXv5Vp/A

https://jbcollier.smugmug.com/Scooter/i-CDmmdvd/A

https://jbcollier.smugmug.com/Scooter/i-dQ5VGrQ/A

https://jbcollier.smugmug.com/Scooter/i-Wtsnkzv/A

Looks original to me. Someone has sealed the ends with the good lord only knows what. Try using a razor first.

[jbcollier]

Use heat on the nut.

[Big Al]

Thanks John. I'll give it a try.

[Big Al]

Heat worked a treat, and the brass nut unscrewed without any drama. Someone had used a white sealant not known to man back in 1955, but both end plates pulled off the silencer body quite easily, and I have scraped the gasket channels clear.

The inside of the silencer doesn't look too bad, so I guess it has been cleaned out fairly recently. I will give it all a good wire brushing, and get some paint on the casing.

Can anyone tell me what to use in place of the original asbestos string in order to seal the end caps (not white sealant please!)?

[jbcollier]

The silencers don't get that hot. You could use Permatex Ultra Black sealer:

https://www.permatex.com/products/gaske ... t-maker-4/

[Big Al]

Thanks John.
I see there are also other similar products available over here in England, as well as Permatex, which are both heat and petrol/oil resistant, so I will do some further research.

[Big Al]

Permatex Ultra Black is quite expensive to buy over here in England, but Visbella Black Silicone HT (to 600F) seems to be a good alternative.

The person who last assembled the silencer used two non-standard washers under the brass top hat nut because, without these, the end plate cannot be tightened down sufficiently onto the silencer body to get a gas-tight seal. There is not enough threaded length on the long rod.

The spacer shown in the manual, which fits between the removable baffle and the separate end plate, is missing from my silencer.

I will send you a photo of the stripped down silencer, which I hope you can post here for others to see.

Many thanks

[jbcollier]

https://jbcollier.smugmug.com/Scooter/i-6XQcxnD/A

[jbcollier]

You can make up a spacer with some stainless or copper tubing.

[Big Al]

Thanks John. I have some copper tubing, so I can make up a suitable spacer.

I'm a bit surprised that a separate spacer was used in the original silencers. If it is too short it will surely rattle, and if it is too long it will prevent the end plate from making a gas-tight seal with the body.