175TS with 125S engine project

[George]

Yes, better black, but mine is hidden inside a dummy case so is not visible.

I also have one on my 250. It really showed up, so I just painted it satin black with Wilko paint, it's proved fairly durable so far.

Good idea

[George]

Bit of an update. While I am waiting for Amal parts I thought I would fit the 3.4mm dia. good used condition valve springs I purchased to replace 3.5mm dia. 250 springs. When removing head noticed one head bolt was loose in crankcase thread. Closer inspection revealed damaged thread possibly previously fitted by PO with dirty bolt threads. After arranging to prevent swarf entering crank case helicoil fitted.
Valves and guides are worn with some oil passing through. Plan on changing next winter as I would like to get some miles in this year.
I noticed that guides Nigel Lacey sells have grooves for oil seals, should be an improvement on original without seals. My guides look to be cast iron so could be original. Have to get valves from Jesus Guzman as different to Italian valves.
According to manual guides to be removed cold, opposite to any guides I have ever changed ?
Would anyone be able to tell me valve seat angle and relief angle. Looking online for valve cutters with 7mm guide I can only find sets for £70+ Ouch. Lot of money for something I may never use again.
Roll pins holding the inlet spring base look worn, base loose on pins. Could be quite a problem getting old pins out of blind hole.

[Jordan]

Removing valve guides cold from an Al alloy head makes the bores bigger. It can be done if you have oversized ones to refit.
You'd need hole measuring tool to order the correct o/s.
I don't see anything wrong with heating the head first, and never heard of seats coming loose for doing that.

[LaceyDucati]

Regarding the lower retainer plate location pins. If you grip the roll pins with mole grips the roll pin compresses and can be removed relatively easily by a twisting motion. That follows for Italian heads.....as long as the Mototrans pins are not unusually brittle....otherwise it's back to the welding set for recovery trick 2!
Nigel

[Jordan]

To prevent a roll pin from breaking when gripped, a small pin that just fits inside it could help.

[LaceyDucati]

Jordan

Yes that can help with the clutch pin, but "generally" speaking the 5mm head pins (certainly in Italian heads) are not that brittle and the act of squeezing them is what reduces the tension and allows them to be easily removed. I have preformed this hundreds of times without ever having a pin snap off. The problem with the clutch pins is being smaller the case hardening is often proportionally a greater part of the material and therefore they are more brittle. In this instance using a pin in the middle can as you say be a help as more often than not if squeezed the clutch pin will snap off.

Regards Nigel

[George]

Thanks for the tips Nigel and Jordan. I am now looking for a company to fit new valve seats and guides. I have decided to get head done professionaly.

[George]

Having new valve seats fitted is looking very expensive. Would anyone be able to recommend a company with Ducati experience. I am wondering if it might be cheaper to find another head with reasonable seats and fit new valves / guides. Not sure if Spanish and Italian heads are compatible. Hopefully Jon may know as there is a good Italian head on EBay cheaper than having work done on mine. Nothing is simple with a Ducati.

[themoudie]

Aye George,

I believe that I have already suggested in another thread on other matters that a email to Andy at SRC Classic Motorcycles might be able to help:

office@scrclassics.co.uk

They are based at Soham, Cambridgeshire, so not that far away, once the lockdown is lifted.

Good health, Bill

[ranton_rambler]

George, rather than new guides, can you get them K-lined. That is what I did and seems to have solved my oil consumption although not done many miles yet on the Ducati. Guzzi has about 1000 miles on so far.
Saves disturbing the fit between the guide and head and preserves the centring in relation to the seat. Obviously relies on the valve stems being OK.
Ian