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Hi all,

New member here with my first foray into Ducati singles (the garage does also house an '82 Darmah and and a '00 900 SS). I've acquired a basket case '74 450 yellow desmo. I'd appreciate some advice on shimming the engine - I have the original cases plus barrel, crank assembly & head and that's about it however I do have a 250 engine of similar vintage. My understanding is that most of the internals are identical so I should be able to swap the 250 gearbox etc. into the 450 cases. My question is, what am I going to have to re-shim (I'm assuming everything) and what order should I be doing that in?

I've attached a picture so that you can see the world of pain (and cost) that awaits me.

Ian

Good morning Ian,

Welcome to the

the world of pain (and cost) that awaits me.

As a Ducati twin owner you are already familiar with some of the foibles of the beast and the folly of keeping a stable of them!

Your assumption is correct!

What am I going to have to re-shim (I'm assuming everything)

As for the order of this time consuming, theraputic art of shimming; check that the cases are square and the holes are true (Nigel Lacey has found many aren't), con rod in the crank, crank in the crankcases, gears on the mainshaft, gears on the output/layshaft, gear shafts in the crankcases (with the shimmed crankshaft in place), selector drum in the cases (with the shimmed crankshaft and gear shafts in place), shim the gears in the timing chest, shim the oil pump drive to the timing chest outer case, shim the gears/cam in the cylinder head, shim the rockersin the cylinder head, shim the clutch outer case bearing on the end of the crank.

I suspect that others will be along to remind me of the shims that I have forgotten. Nigel Lacey or Eldert probably do the job in their sleep.

Ducati OME, Clymer or Haynes manuals, I use all three are essential and a notebook to write down all the shim values that you set your engine too. Then you will know for next time.

DO NOT REMOVE SHIMS WITHOUT REPLACING THEM ON THE SHAFT FROM WHICH THEY CAME!!!!!

I have been asked to rebuild a stripped motor, in which all the washers and shims were in a separate tobacco tin, with the passing comment "I thought that you might need these as well!"

Finally, if you are not sure try using the "Search" window in the top right of the screen, or ask, this forum is a font of knowledge and experience.

Good health, Bill

Many thanks Bill, that's very useful (even if you confirmed my 'world of pain' comment).

Lots of fun there Ian,,,,,
Be aware the 450’s have a different drive gear and clutch gear to the 250’s
What country are you in ?

Graeme

graeme wrote:Lots of fun there Ian,,,,,
Be aware the 450’s have a different drive gear and clutch gear to the 250’s
What country are you in ?

Graeme

Thanks Graeme. Yes, I knew about the drive and clutch gear (a few hours spent looking at part numbers...). I'm based in the UK.

Ian

Ian, shimming a Ducati single engine from scratch is a pain in the a**se however if you do the job right it will produce a very sweet running motor and be worth all the bother, good luck and keep taking the patience tablets
Cheers,
George

Well worth it as a project. there's a 450 FS in Australia for AU$37k!!

cooperplace wrote:Well worth it as a project. there's a 450 FS in Australia for AU$37k!!

Yes, prices seem to be getting pretty wild don’t they!? Although I now live in the UK, Australia is actually where I’m from (Perth mostly) and I grew up living across the road from the local Ducati dealer (Ross Chapman) which is where my love of Ducatis came from

It took me many hours just to shim my single's gearbox.
The gears and dogs material is pretty ordinary quality so it's a good investment of time to get it as well adjusted as possible, esp. for a 450.
You need to know the sequence of operations, or give the job to someone trustworthy who does.