does anyone else do the exhaust repair like jim Comstock or is he the only one

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bsaboss said:
For those in Australia, Murray at Cyclecraft Engineering in Perth repairs exhaust ports using a screwed in bronze insert. I had my 650SS head done by Murray and it looks identical to the RH10 that I had Jim Comstock do a few years ago. Murray is also a top bloke to deal with.
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Murray at cycle craft engineering in Perth did the inserts in my 850 commando head….a fantastic job…couldn’t ask for better quality workmanship
 
B+Bogus said:
I had exactly the same issue - welded in alloy sleeves broken loose.
I'm in the UK, so not much help across the Pond, but for anyone interested I used David Burton Engineering in Thornton, Lancashire.
The bronze inserts were custom made to fit the larger holes, and it was a first class job.
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I had the exact opposite, a bronze insert started to spin in the head so I got Mick Hemmings to do his repair of welding in an alloy insert. Just goes to show of the two solutions the skill of the person doing the job is the more important factor.
 
kommando said:
I had the exact opposite, a bronze insert started to spin in the head so I got Mick Hemmings to do his repair of welding in an alloy insert. Just goes to show of the two solutions the skill of the person doing the job is the more important factor.
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Funny old world, innit??!?
David Burton uses screwed in inserts, which may be a factor?
 
jseng1 said:
Its a bad design. The problem is the flange on the end of the pipe - it pounds the exhaust nut loose. Cut off the flange and press or thread a tube into the head that fits the ex pipe. Or add a sleeve to the pipe so it fits the ID of the ex nut and hold the pipe in with a spring. My solution is below - the nuts are tightly screwed in until the threads bottom out (no exhaust rings). Silicone sealer on the exhaust nut threads for security and a collar on the ex pipe with a thin smear of silicone sealer on the collar OD. One thing I haven't tried is a slight taper on the collar. If you braze on the collar you must use phosphorus bronze.

does anyone else do the exhaust repair like jim Comstock or is he the only one
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Correction - silicone bronze is the brazing rod to use (not phosphorus bronze).

Has anyone tried using a tapered sleeve fastened to the pipe and held in with a spring? This could be done without repairing the threads (as long as the taper sealed). You would have to cut off the flange at the end of the pipe and use a small amount of silicone bronze to secure the tapered sleeve to the pipe. Then add a spring as in the photo.
 
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For the folks in Europe:
I should get soon a Commando head to have a better look, but by judging from pictures i assume (being an ex long time TIG weldor and by now int welding engineer) that within reasonable time (beginning of next year) i could if need arises in central Europe also offer such services.

Kind regards
Christian
 
I use the outer and inner head bolts to anchor from and some 8mm stainless eye bolts and stainless plates/ collets to hold my exhausts on
There's no modifications to the head so one day I could get the threads repaired
I've been doing this for more years than I care to remember
Not the prettiest solution but I don't care
 

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cliffa said:
I think if my threads ever let go, I'll get 2 or 3 areas around the port filled with weld, then drill and tap them for studs and fit Japanese style flanges with half collars like these..

View attachment 81698
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I did that back in the 70s but only had the bike another yr after that. Think i used yam xs650 bits.
 
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baz said:
I use the outer and inner head bolts to anchor from and some 8mm stainless eye bolts and stainless plates/ collets to hold my exhausts on
There's no modifications to the head so one day I could get the threads repaired
I've been doing this for more years than I care to remember
Not the prettiest solution but I don't care
Click to expand...
Ingenious !!
 
For those in Australia, Murray at Cyclecraft Engineering in Perth repairs exhaust ports using a screwed in bronze insert. I had my 650SS head done by Murray and it looks identical to the RH10 that I had Jim Comstock do a few years ago. Murray is also a top bloke to deal with.
In New Zealand John Saywell inserted Aku-bronze inserts into mine. Perfect fix.
 
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