Engine Mounting Spacers

[Pallijen15]

Hi, I've just been cleaning my Douglas MkV 1951. Between the frame and gearbox/engine there is what I think is an adjustable spacer, of which was loose. According to Spannerama these are found on Plus and Dragonfly models, which I assume is why I can't see them in my spares manual. When I extend the spacer should there be anything between the gearbox/engine spacer to protect the alloy? Is this spacer incorrect for this model? How tight against engine must it be? Thanks for any advice. Paul J

[isettaman]

Hi Paul
I may be corrected by the more experienced posters, but I have these on my 80 Plus and the idea is that they are used to adjust the position of the gearbox in the frame so that the final drive sprocket lines up with the rear wheel sprocket. On mine, the wider one goes on the final drive side. It is important that they are a good tight fit and the nut on the footrest bar is also tight as it takes considerable strain from the operation of the rear suspension. Don't forget to have the front engine bolt slackened off when doing the adjustment and then tighten it afterwards.
I had a bit if fun with mine, as there is the front to rear wheel alignment to get right as well as the chain tension adjustment to take into account when getting the sprockets lined up.
Dave

[tck]

Yes I think the chain line dictates all. On my rebuild I found a length of copper water pipe on one side!  I shall be making up some substantial alloy spacers when I put it all back there must be a slide fit when all is assembled with no movement and I wont be using that bit of pipe for a pattern. (Now back to that stuck flywheel )

[Pallijen15]

Isetta man and TCK. Just rereading  y old posts and can't see a reply from me. Apologies if I haven't replied and thank you to you for advice. Paul J