Exhaust thread repair in Melb?

[davamb]

Hi all,

I've been aware of damage to the RHS exhaust thread on my bike for quite some time, it's been serviceable, but it isn't getting any better. It's now time to do something about it. Can anyone advise what the options are and if there's anyone in Melbourne (Aus) who offers a repair service at an acceptable cost?

Thanks,
Dave.

 

[Fullauto]

Hi Dave, Don't know about Melbourne but if you don't mind a bit of postage, Ben at British Imports in Perth does an excellent, really clean job. Can't remember how much he charges but I'd recommend doing both ports at the same time. He uses bronze inserts. Hope this helps.

 

[GRM 450]

Geoff Howie in Brisbane welds up and re threads. Howie Engineering. He will need an empty head and the exhaust nuts, and as is the way with these things, lots of time. Cost me $200

 

[Mark F]

Dave if you were going to send it to Perth I think I would use Murray from Cyclecraft Engineering. Murray uses a bronze insert, has been doing them for years and has literally done hundreds of them. He is the go to man in Perth for Commando's.

 

[davamb]

Thanks all,

yeah remember your trouble with the port last year Graeme, was the other port still serviceable and $200 for just the damaged one?

Comments on Bronze inserts versus weld-and-retap? Is the insert better: stronger, than the original?

 

[GRM 450]

I had both done as if 1 was sus my luck the other one would have let go as soon as I refitted the head. $200 for both ports. Graeme

 

[tricatcent]

If you have an internal thread that is cross threaded or has been damaged somehow by abuse, you can fix it by using a tap as a scraper. Get at tap with the same number of threads per inch as the part you want to fix. A bottom hole tap is best. Use a set of vise grips as a handle. Then you can go all around the thread cleaning up the damage using a swinging motion. The inner parts of the thread that are un damaged act as a guide so that the tap follows where the threads should be. Usually there is a tap much smaller than the hole you are fixing that can be used as the scraper.

 

[Foxy]

If my memory serves me right, a few issues back of Just Bikes mag someone was advertising stainless steel inserts to fix Commando heads. Victorian number too?

 

[Nortiboy]

Comments on Bronze inserts versus weld-and-retap? Is the insert better: stronger, than the original?

Had a few done in Maleny QLD. Each insert thread is machined to suit the nut. They all vary slightly. Bronze is tougher. You risk deformation with welded inserts. Go the bronze. You can pm if you want to send it that far.

 

[Stuart SS]

Hey Blokes

Fortunately I have never experienced this issue with stripped threads on my Commando ~ but highly recommend fitting the lock tabs and make sure you have an exhaust seal ring ~ before locking up!

when I first took delivery of mine~ the LH exhaust was incessantly leaking. I would tighten and remove the left muffler - stick some selastic in the joint. It would go for about 700 miles and then start back firing and leaking. So repeat the process ~

Eventually I found that the wanker that put it together had left out the seal ring !!!

( I still give myself an occasional up-cut for neglecting to suggest GRM fit the lock tabs as Graeme did ask for suggestions list.. Sorry bloke !!!! )

 

[Nortiboy]

Hey Blokes

Fortunately I have never experienced this issue with stripped threads on my Commando ~ but highly recommend fitting the lock tabs and make sure you have an exhaust seal ring ~ before locking up quote]

Never used a lock tab or wire in 30 years. I use an aluminium/asbestos seal ring, neverseize on the threads and treat the nuts like a spark plug, 1/4 turn past seated. The first 5 or 6 rides, barely lean on the tool to make sure it is nipped up, but thats it for road use. I have used bronze inserts when I buy a screwed head.

 

[Stuart SS]

Nortiboy

I have to admit I am currently experimenting with the same seal rings ! ( And actually, I also applied 'never seize' ! )

I have the lock rims fitted but have not tabbed them over ~ and I am currently monitoring the new zorts roses to see how well they seal or stay in place ~ without the locks ~ So far I am pleased to see the roses have not budged ~

( In stating that I figure that some like to tighten and forget ~ in which case I would again recommend the lock ring ~ the consequences are subject of this post , right? )

 

[Nortiboy]

Nortiboy

I have to admit I am currently experimenting with the same seal rings ! ( And actually, I also applied 'never seize' ! )

quote]

I have about 20,000 mles on 3 Commando's and the (stock) exhaust nuts have not moved. with this method. I carry a short C spanner and check them regularly but they have never moved. Once the motor gets real hot (no worries where you are) you nip it up and thats it.

 

[Fullauto]

I've found with the bronze inserts that the nuts give you less problems with backing out than in the alloy threads.

 

[davamb]

Thanks guys, looks like the wallet wins and it'll be GRM's recommendation Howie Eng. I'll get in touch with him and see when he can slot me in in the new year.

 

[Brooking 850]

Hi guys although many years since a stripped head thread for me, the method mentioned of tightening exhausts collars is true, nip them up after a few runs when hot. I don't use any fancy crush washers, I have put a centre punch mark on the head and the fin opposite that on the exhaust nut, (when it as it's tightest)then when cold rubbed a green paint stick into the punch marks, wipe off the excess, which leaves a minute green(or colour of your choice) in the bottom of the punch marks spots opposite each other, then a quick glance you can see iff there is any creep backwards(unwinding), even when you are riding, or first thing asa pre ride check, no need to get the spanner or brass drift out!!!!
If you are running a balance tube as I do, I had to get a new set of headers made as my LHS pipe cracked at the weld right at the top outer sleeve,and stunb weld, it turned out the stubs for the headers were 3 degrees out to each other which put a lot of load on the weld. Wonder why I had backfire on overrun/down hills off the throttle!!!
Follow the manual to a letter when setting them up, can't go wrong.
Regards Mike