Broken Exhaust studs, mangled holes, considering ebay...

Hi all
been a while since I have been on, kinda missed the place. =)
Anyhow, my 81 xj650 maxim has a few broken exhaust studs and one that the PO tried to drill out and mangled the hole. I am considering just buying a new head via ebay and wanted to know if anyone can tell me exactly what to look for. like I see a lot that say 82 650 seca turbo, will this work?

 

Look (and ask the seller if you cannot see for sure) for broken fins, and make sure the cams are included.
I got a new head complete w/ clean cams for my 700 for $28 on ebay, no way I could fix my old one for that.

 

ok. is there any reason that I would not want just the bare head and reuse my cams ? Is there a "wearing together" thing?

 

Thats what I've been told, and also read here. My original head was/is probably serviceable but my cams were badly rusted and pitted making them useless. I had thought to just replace the cams (and a few valves), but searching here made me decide to swap the entire thing. Remarkably, finding a loose set of cams was generally far more expensive than replacing the entire head w/cams, anyway.

 

It's best if you can find cams mated with the head.

BUT, as far as I know, you can replace them separately anyway..........But if you swap cams, then you're going to have to check clearances again, too..... if you buy a complete assembly, then check clearances and you should be good to go.

So, back to the original question:

If the holes are that mangled, get another head. If it's just one hole, consider taking the head to a milling shop and have them extract the broken studs and repair the hole.

No, you can't put a 650 turbo head on it.

You must look for an 80/81 head, as that was a non-YICS head. The 82/83 was YICS and is different.

Like Hank said, you can find them cheap enough on ebay, or here, and would probably be cheaper than sending it out for machining...........

good luck.....

Dave Fox

 

You can swap cams into different heads; but in doing so it's important to check the cam journal/bearing clearances. This is easily done with Plastigauge and there is a published tolerance range.

 

Dave!
I was actually thinking about getting ahold of you on this one. We met once, I came to your place and bought a front rim from you a few years back. You wouldnt happen to be holding onto the head I might need would you =)
Steve

 

I'll have to look.... Give me a call . If you don't have my number anymore, I'll pm you with it....

Dave