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Hey fellas,

I took my head apart today to inspect it before I get the cylinder back. Can you please tell me what you think caused the exhaust valve to have a ridge on it like this that would prevent it from sliding out of the guide? I had to actually grind a little bit so it would slide out. I'm assuming I will need to replace this valve?




I actually had to grind the ridge a little bit to be able to remove it:


Also a chunk missing from the spring holder...will have to find a replacement:

Welcome to Italian metallurgy.
The ridge on the valve stem means it was a bit too soft. Sometimes seen - no big problem.
You did right to file or grind it down to pass through the guide.
If it's within spec in other respects, I'd consider using it again if on a budget.

Jordan

Well, the rest of the bike is in tatters so I reckon I am on a budget, but for $30 changing it out seems the smart move, right? It's not going to get less soft??

Another thing, what is the proper name for the valve spring retainer? I'm trying to find a replacement but having a rough go of it! These darn 160's are tough to find parts for!!

Thanks!

-Matt

Are the spring retainers on your 160 the same as wide case retainers?
I have spare retainers if they fit.
Graeme

Graeme,

That's very kind of you. I would very much appreciate that but I will have to defer to others on here whether they would fit or not as I simply don't know. I can take some measurements though; that may tell us.

the valve spring base plate looks like a stepped one used on 125 Ducati's to

Eldert

MayerMR wrote:Another thing, what is the proper name for the valve spring retainer? I'm trying to find a replacement but having a rough go of it! These darn 160's are tough to find parts for!!

I think the valve springs used on desmo singles are the same as on your 160. (see parts lists)
Maybe the spring retainers are interchangeable?

Jordan

Eldert wrote:the valve spring base plate looks like a stepped one used on 125 Ducati's to

Eldert

Eldert,

Thank you, it is stepped...I do not know if it is the same as a 250. I did a drawing, hopefully it will help identify it. Am I calling it the correct thing? "Valve Spring Retainer"?

An important dimension is the diameter of the spring wire.
I think you'll find the 160 is smaller than 250, except for desmo which used weaker springs.

Jordan

The tip of that valve looks kinda beat up; another reason to replace the valve. You should have a close look at the valve adjustment screw. If 160's are the same as other screw adjuster type bevel singles, there is a captive ball in the foot of the adjustment screw. This ball has a flat ground into it which is supposed to mate with the tip of the valve. Sometimes the ball gets loose in the socket. The spring anchors in a 250 are flat, won’t work in a 160. You need 125/160 anchors. 175/200 look similar, might be the same but even more difficult to find. Nice drawing, you have talent. Matt