Broken fin

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Jun 12, 2007
I've just taken the head off my 850 and there's a borken fin on the cylinder. Is this very serious or could I carry on with it broken? It's about 2cm wide an 8cm long.

Many thanks.
Wow, that's a pretty big chunk of fin missing!

But, it shouldn't cause any overheating problems, unless you get stuck in really hot, stop-and-go traffic. If you have the broken piece, you might be able to find someone to braze it back in place.
You can't braze the aluminum fin back on, but a good welder can weld it back on.

Shouldn't be much of an issue beyond cosmetic.
The fin is on the cylinder, correct? If so it is iron and can be brazed. I think Paul believed it to be a head fin.

This is not uncommon. My buddies '69 'S' (bought new and never had head off!) had the top cylinder fin fall off while idling in the driveway! That finally convinced him that we needed to re-do the isolastics.
Yep; re-read the post, and though he mentions taking the HEAD off, he then states that the CYLINDER had the broken fin.

I'd still want it welded instead of brazed.
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