loose valve stem seal

[Roland]

I found a loose valve stem seal on exhaust side, scrambler 350.

What to do?
I think i know the answer, but i am very interested in your opinion or comments about it.

My Laverda 1000 did not have seals on exhaust side and it worked well.
Obviously there are different situations for in/out valve stems, sucking and blowing.

So i will cut it and remove it.

What do you think?

Regards, Roland

[Duccout]

Hi Roland,

Is it possible to push the seal back in place with a plastic probe of some kind? That is not a genuine Ducati seal either.....

Cheers,

Colin

[Jon Pegler]

That could be the correct seal for a Mototrans machine.
Quite a few widecase Spanish Ducatis used a similar seal, as used on many car engines.

Jon.

[Roland]

I can push the seal back in place, but after some kicks, it is off again.
Completely worn out, and i cannot see how it should keep the position on this guide's geometry.
Yes, there is something wrong here...
Some work has been done on this motor, dont know.
Inlet has another seal and is in place.

Need some passionate hour for this surgical operation.

Plan B is to install a new seal, but which type is to fit here?

[Duccout]

Hi Roland,

I cannot see a lip on the top of the valve guide for the seal to locate on? If that is not there then the seal will not stay in place. Would it be possible to hold the seal in place with a small cable tie around it ?

Cheers,

Colin

[Jon Pegler]

Those valve guide seals fit onto a smooth portion on the top of the guide.

The seal itself has a number of concentric rings formed into the inside of the seal and this grips onto the valve guide.

If it slides on and off easily the seal is worn internally and will not stay in place.

It is not possible to put a cable tie around the seal body as the main body of the seal is metal.

Find someone who works on car cylinder heads and find the correct seal.

I seem to remember using a valve guide seal off a Renault that fitted the Spanish guides.

Jon

[Jordan]

As mentioned in the first message, lack of a seal on the exhaust guide is not a serious condition. Cutting the loose one out is a simple fix.
I think I can see a slight groove near the top of the guide.
Ducati made seals as a single piece of rubbery stuff.

[Roland]

Thanks all.

I have new seals here, but the guide is different to what it should be.

So what do i actually have, is this original setup?

[Roland]

Done.
Feeling better now