While I dont actually intend to use these silencers on this bike just yet as Im going to run the OEMs I repaired, I think these are a good option for this bike in the future so this is the best place i think to put the info, not least as the thread is about a 51L engined bike.
Ahh... I do like 51L pipes... I'd buy more if I could find some for a good price... Anyway...
A while back I bought a set of 51L exhausts and while they look to me to be standard front pipes, the silencers had been replaced.
Now, as you might recall, Mr Midlife and I tend to get excited about replacement 51L silencers so I thought id pull em apart and look at what had been done. They needed a clean up anyway so I set to work...
What started as mild interest has morphed into a bit of a rebuildā¦ of course.
The design isnāt that bad really, but its execution was not that great. After spending time with them I now believe the builder was actually at least two people with varying skill levels. They seem a bitsa job to say the leastā¦ and a genuine 'Curates Egg'ā¦ who ever thought Iād get to use that term on a bike forum lol!
I fought to get them apart, almost to the(ir) death lol. The single rivet holding the baffle end in place drilled out easily but the rest of the baffle was basically āglued into place' with sponge. Great.
I did eventually pull and hammer them, but one disintegrated on exit, dropping parts on the floor. Sighā¦ I think the braze has let go in use.
I gave them a clean and worryingly a couple of needle bearings fell out of the cans. They were stuck in the sticky oil in the bodies.
Ok, construction:
Stainless tube was used for the bodies, its 304 I reckon as it does surface rust. Itās heavy but solid. Stainless plates have been welded on the inlet end, but that was done with mild steel MIG welding wire. Who does that!?
The end caps and centre were done really interestingly. They are made from LC baffles. Im thinking the maker or owner was a proper fan of our bikes to have had these lying about when he was repairing the cans on a YPVS! Good lad!
The builder took the LC baffle and removed most of the initial 'baffledā section, leaving the fluted/coned end and the holey pipe (technical term, not churchy).
(pics after blasting and some repairs done and with an original LC baffle so you can see what has been done)
They then welded this to a wider flange and then welded that to a steel outer band, rolled from sheet.
A lot of work and looks like something from an 80s off road bike which is kinda cool.
The welding of this is pretty neat looking. Butā¦ the welds were never dressed back and on one of the LC baffle āconesā still has the nut welded in place, plus both these ānut holesā were not welded up.
Its weird that someone would have someone do nice welding on something and; A, not finish it and B, never dress the finished article.
I ground off the (now spare and useless) nut, welded up the bolt holes and ground back.
I also cleaned up all the old welds and dressed them back on the lathe.
I rebuilt the snapped inside parts with weld rather than the OEM braze which fails and also welded up the two parts of the triangle shaped baffle that directs the gasses as they enter the silencer which I donāt think the builder knew were seperate parts and probably wondered where the rattle came from lol
I also converted the rivet to captive nut and bolt instead.
After another blast these baffles got a coat of KBS Extreme to keep any rust at bay before they get covered in oil again lol
Next it was on to the bodies. I had to clean up the scratches and also grind back the welds to improve them.
The welds proved a bit more problematical. I could have cut the ends off and started again and used stainless welds, but that was a bridge too far for a refurb.
In the end I decided to paint the welds a bit like Yam did with the 500 cans, which uses black paint over the welds. In may case I had some KBS Extreme in silver and used that - if nothing else it will stop them rusting again.
EDITED! OMG! please excuse the grubby oily fingerprints on the bodies... The brushing looked mint until I moved them around for the pics...
So they are doneā¦ and of course now stored away encased in my patented sock system! LOL
All in all quite a bit of work, but I think Ive improved them along the way and its insight into another take on replacing the OEM silencers, which if course could be done with the captive can 350 versions as well etc.