Stripped exhaust port thread

[70sbikes]

My 1976 3 1/2 Sport has a stripped exhaust port thread. I'm after recommendations on who can fix this. I am in Australia, but I'm willing to post the cylinder head overseas.

Cheers

Trevor

[MickeyMoto]

It may be cheaper to source a new head.

[hendre]

maybe you can show this vid to a local machine shop and they can solve it for you?
https://www.youtube.com/watch?v=ZfFbA9Y3jHw

the author of the video is on the forum (EVguru) and he may do it for you (did some in the past)
other adresses (from another topic):
https://www.lussoveloce.com/
https://www.morinispecial.it/joomla/ind ... cle&id=177

[Daddy Dom]

Try Gary Jolly at Reliable Engineering in Adelaide.
DD

[70sbikes]

It may be cheaper to source a new head

By "new" I assume you mean used? I thought about that, but I reckon there wouldn't be many used heads out there with pristine threads. The aluminium is now 45+ years old, and has been through countless heat cycles, meaning I'd probably end up back where I am now...

Try Gary Jolly at Reliable Engineering in Adelaide

I actually found another motorcycle engineering place in South Australia! I reckon Zuckerberg was listening in to my conversations, because this place popped up in my feed. I was scrolling through his posts, and the one that caught my eye was a Norton Commando head with beautiful bronze inserts. I spoke to him, and he has actually done Morini exhaust threads in the past. Heads are now boxed up and will be posted tomorrow. It's not going to be cheap, but given 3 1/2 Sports are fetching around $15,000 AUD, it will be worth it!

[sheddweller]

Would you mind posting some contacts for the engineering business in SA that has done inserts for Morini heads? I am in Queensland and have some damaged threads, as do at least 2 other local Morini owners. Thanks, Garry

[70sbikes]

Martyn Adams at MDA Motorcycle Engineering.

https://www.facebook.com/search/top?q=m ... ngineering

martynadams.eng@gmail.com

0421 874 513





With postage, it cost around $1,200 AUD. Before the naysayers reply with "The bronze inserts won't stay fixed in place", Martyn does the same work on Norton Commandos (and has done for many years), knows what he is doing, and has nothing but positive feedback on his work. He's a frickin' genius! Get it done before he retires or shuffles off the mortal coil!

Trevor

[MickeyMoto]

That looks like a very nice job. Shame he is in Oz.

[norbert]

Sören the vikingo is doing the job as well (you´ll find it scroling down )

http://morinist.dk/morini/tyskdele.php

[70sbikes]

I didn't mention that Martyn's inserts meant the "dome" in the exhaust port was machined off. To get the exhaust pipes to fit properly I had to grind away the taper on the half-rings. This took a while, as I didn't want to ruin the hard to obtain rings, so it was grind, check the fit, grind, check the fit, until they were perfect. Martyn also recommended using two exhaust gaskets.