Manky's XS650 Yamaha

[triker_Chewie]

MM you need a finishing touch to match up those great side cases? here you go : http://www.ebay.co.uk/itm/Gas-Tank-aluminum-engraved-one-of-the-kind-bobber-chopper-Harley-/272264012426?hash=item3f6433228a:g:hnQAAOSwbYZXUxts

very shallow if it is engraved. probably sculpted in filler

[Olds]

It's done by what they call chemical engraving. What everyone else calls etching. Think they are using UV developed etch resist and templates.
Same as making circuit boards.

[Manky Monkey]

Aah, used to do something similar when making lithographic printing plates when I was an apprentice, about a thousand years ago.
Hello Ben Nice to see you back mate.

[Manky Monkey]

Hmm, really struggling to raise enthusiasm for this at the moment.
Drove over to Berkshire after work this afternoon & collected the stainless exhausts from Bernie the TIG welder. He's done a lovely job -I literally can't see the join, (I had to cut the righthand pipe in half & take a centimetre out of the middle, where it passes between the frame tubes). As well as welding it back together & buffing out the weld, he added the flanges to the ends. 30 quid.
Great. Unfortunately they still don't fit. The left one's not too bad, but the right fouls on the frame down tube. Not Bernie's fault -I had to guess at how much to take out & what angle the 2 pipe halves should go back together at. Maybe pulling the bend in tighter at the cylinder head would help, but I'm not sure. I'm almost tempted to cut a small piece out of the side of the pipe & reverse it, so that it curves inwards to clear the frame. That would mess up the gas flow, but it's not a race bike, just a daily rider.
I think I need to add a second pair of gaskets in the ports too to pack the pipes out, as the finned collars bottom out against the cylinder head before tightening up on the pipes.

[Manky Monkey]

The back end's giving me problems too.
The previous pipes, which were smaller diameter, were held with a pair of circular clamps, which bolted to a stud welded to the frame, with a small gap between the 2 pipes. Because the new ones are a bigger diameter, they need to lay tight together down the side of the bike. Which means I can't use the mounting stud. I'll have to cut it off the frame & touch the paint in, but at least it'll be hidden behind the pipes. So, how am I going to clamp the 2 pipes together & attach them to the frame? Any ideas? I've already drilled & tapped a 6mm hole in the frame tube to fix the back end of the chainguard, so I think I need some kind of stainless strap that wraps around both pipes & hooks over the frame, bolting to the chainguard mount.
I've got baffles to go in the end of each pipe, so could drill through the strap & into the pipes, then bolt through into the captive nuts inside the baffles to hold the pipes inside the strap. That'd work.   

[Olds]

Looks to be almost there. Unless the clamps are crushing the exhaust gaskets rings slightly, you don't really know how the tubes are going to fit. Add a spacer between the clamps and the flanges (not double up the gaskets).
How long are the flange rings and are they in the right place ? Seems they should be 7mm mounted 8mm from the end of the pipe (std diameter pipes).

[Mendalot]

Andy, I made these brackets from sheet stainless steel and have some left over if you would like it. Could you not make up two sleeves that wrap round each pipe and clamp to your stud if you cut it down. (obviously not with the ugly hose clip though )

Manky's XS650 Yamaha

[Manky Monkey]

Aah, didn't think of that Dave -my flanges are welded flush to the end of the pipe, (I think Tom's got my original down pipes so I had nothing to compare to). When you say how long are they, you mean how thick? They're 2mm. So how thick do the spacers need to be?
Appreciate the offer of the stainless Sir. I think I'll do something similar, but in 25mm x 1mm stainless strap. The pipes need to sit right where the stud is, so it needs to come off, then I'll try & make a strap that's kinda figure of 8 in profile with a curved tab that'll sit over the frame tube.

[Olds]

I assume 5mm. But it depends on the finned clamping rings. Best bet is to put a bit of plasticine (or similar) on the pipe, between the flange and the clamp ring. Push the pipe right into the head (without gasket ring), push the clamp ring against the head to compress the plasticine. That should tell you how thick it needs to be, to compress the gasket and leave a small gap between clamp ring and head.

[Manky Monkey]

Right-o.

[triker_Chewie]

Aah, used to do something similar when making lithographic printing plates when I was an apprentice, about a thousand years ago.
Hello Ben Nice to see you back mate.

I'm here every day Andy. just a little quiet

[Manky Monkey]

Sneaky!

[Manky Monkey]

A bit of a guesstimate, but I went with 6mm thick stainless spacers, custom made by:

http://www.lasermaster.co.uk/easy-order

for about 7 quid the pair. I didn't think they'd slide up the pipes & around the multiple bends, but surprisingly, they did.
I've modified the rear mounting on the chainguard & am waiting for some stainless flat strap to turn up in the post so I can make a new clamp for the back end of the pipes, to fix to the same bolt as the chainguard. Still looks like I'll need to recess the front of the righthand pipe to clear the frame, but have to cut off the old rear exhaust mounting stud cos the pipes don't sit right with it in the way.

[Manky Monkey]

Rear exhaust mounting stud hacksawed off & filed flush. Now I need to repair the paintwork.

[Manky Monkey]

Exhausts tried in place now the stud's out of the way. They don't fit. They will fit, but need some cutting & tweaking to sit right & line up with each other. Really needs to be done on the bike, rather than me cutting & marking them & taking them one at a time to the TIG welder, (I'd have to do one, then get the other to match it). The ideal person would be my brother Steve, who's got the space to have the bike in his workshop & can play with it at his leisure. He's done me a lot of favours but I'd rather pay him the going rate as he's self employed & I don't want to outstay my welcome. I'm resigned to this thing taking as long as it takes now.
Both pipes need pulling in at the back end & do flex a bit but I don't want to bolt them up under tension or they'll end up fracturing or cracking the head. They also need to line up one above the other.