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Just been adjusting my Tappits to try and sort out poor readings after a leakdown test.

The process went well but on two of the adjusters top nuts were 7/16" not 1/2"
These were on number 4 and number 7 Valves.

Would this cause any problems?

Horse

I don't see how that could cause any problems. They are just lock nuts, to maintain the adjustment. Odd, though - usually a 7/16" AF nut fits a 1/4" thread, and a 1/2" AF nut fits a 5/16" thread. Did you notice if the thread size on those two was different than the others?

Hi jimm, thanks for the reply.
No I did not look at the thread size but will do when next in there.
She has been running like that for a long time I think.
Thanks.
Horse.

When I checked on part numbers for the tappets and adjusting screws they seem to remain the same MB, GPW, M38, CJ L-134s. It's as
shame I do not have access to the French built MB's to see if they used standard Willys parts or their in house manufactured meteric sizes.

On the other hand I have been a mechanic for 59 years and on rare occasions I have come across varying hex head sizes on the same diameter/thread pitch fasteners.

Thanks for that.
So I am probably not the only one with odd nuts, so to speak.
Horse

Yep, there are dozens of us!