78XS rehab

[Eab]

Headers look right and sweep away from the oil filter, the mounts on the muffler appear to be quite adjustable, no crossover to deal with. Prob an easy bolt up. Didn't see a stop for side or center stands, other interference would be with the rear brake pedal.

my guess = okay

---Bax

Did some other digging around and found a set that looks a bit cleaner and Should match up OK, fingers crossed

[jetmechmarty]

Did some other digging around and found a set that looks a bit cleaner and Should match up OK, fingers crossed

That's a Mac 4 into 2 with taper tips. It looks like they just got pricey! It will fit any XS1100.

[Eab]

That's a Mac 4 into 2 with taper tips. It looks like they just got pricey! It will fit any XS1100.

Wasn't quite sure what they were exactly, thanks for the tip! Do you know if I'll need to rejet, swapping to these from stock?

[jetmechmarty]

Do you know if I'll need to rejet, swapping to these from stock?

I expect you will not. My Special runs on stock jetting. The airbox has a K&N filter in it and the exhaust is a Jardine 4 into 1. It goes like a locomotive with well over 100,000 miles on it. YMMV

[Eab]

I expect you will not. My Special runs on stock jetting. The airbox has a K&N filter in it and the exhaust is a Jardine 4 into 1. It goes like a locomotive with well over 100,000 miles on it. YMMV

Lucky day! This community is friggin awesome. Many thanks.

[Eab]

Just finished rebuilding the calipers and now I'm working on the rest of the brakes. Front master cylinder piston was/is frozen inside it's housing. I pulled the (corroded) retaining ring out after pulling off the boot, and after a few smacks with a dowel and mallet I can see the piston. It doesn't look great! Wondering: does this look like the corrosion is terminal for the whole unit? The piston looks ROUGH and I'm worried the housing might be scored to the point of not making a good seal where it's necessary. If I can save some cash (and keep stuff out of the landfill) by rebuilding with a kit I'd prefer that, but I don't want to waste cash if seems to pretty obviously be a lost cause. Any thoughts?

[Bax]

Hi Eab, I never want to roll the dice when I squeeze the brake lever....... When you get the piston out and the bore is not pitted, excessively scored, or otherwise damaged, the rebuild kit has a replacement piston. Make sure the spooge hole is clear or the calipers will not return.

https://www.brakecrafters.com/collections/1981-yamaha-xs1100-sf-sg-sh/products/1979-1981-yamaha-xs1100s-special-front-brake-master-cylinder-rebuild-kit

Nice replacements are available from Mike's XS. Integral aluminum reservoir with sight glass.

https://www.mikesxs.net/yamaha-xs650...-models%2F1981

---Bax

[jetmechmarty]

Contact Michael Morse at 650Central.com. You'll be glad you did! He's a brake expert.

[bikerphil]

Yep, if you are going to upgrade to a different M/C on a Standard, I would go with a 14MM bore M/C with SS braided lines. The stock 11/16" bore size is fine with rubber lines but too firm with SS.

[Eab]

Hi Eab, I never want to roll the dice when I squeeze the brake lever....... When you get the piston out and the bore is not pitted, excessively scored, or otherwise damaged, the rebuild kit has a replacement piston. Make sure the spooge hole is clear or the calipers will not return.

https://www.brakecrafters.com/collections/1981-yamaha-xs1100-sf-sg-sh/products/1979-1981-yamaha-xs1100s-special-front-brake-master-cylinder-rebuild-kit

Nice replacements are available from Mike's XS. Integral aluminum reservoir with sight glass.

https://www.mikesxs.net/yamaha-xs650...-models%2F1981

---Bax

Thanks for the tips, all. Going to try my luck with the stock MC, it looks (and feels) smooth enough and I'll pump the hell out of it a few hundred times (post bleed) to make sure its OK before taking it out. Trying to manage this initial rehab with minimal expense, then I'll feel it out and see if it's the right bike for me for the duration. So far so good though! Got a rebuild kit inbound for the MC, got the "new" pipes on, the rear break cylinder is in good shape, rebuilt all three brake caliper assemblies and I'm gapping the plugs tonight and hitting home depot for some clear tube for bleeding tomorrow. Had to order new dampers/mounts for the rear turn signals, and that might well be the last thing to do before a trial 1st/2nd gear lap around the block. Exciting times! Not looking too bad for something that lived in a yard for a year or three.

[Eab]

Probably should be in bed BUT, can't sleep until I figure what's up here: got a Mac 4 into 2 to replace my rusted stock set, well-rated parts seller said it was from a 79 (vs my 78) and it seems to sit well in the headpipes and the bracket it came with lines up pretty well but the back end seems too high. I went through that impressive compendium from the euro gang and these pipes are listed, but no permanent mods are needed to run them.

These brackets don't look improvised, yet there are contact points between the pipe and the frame in a few places. My first thought would be that I need a different, longer mount but being new to this, I don't want to rule out that I'm missing something obvious. This is a problem, right? Looks like the previous owner at least had issues with the brake lever, it contacts the pipe before it bottoms out (the MC and system are empty right now though)

[bikerphil]

Your exhaust may have come off a Special, which uses different aluminum foot peg brackets and the brake lever sits slightly further out. It looks like with a little massaging you can make that work on yours somehow.

[jetmechmarty]

These brackets don't look improvised, yet there are contact points between the pipe and the frame in a few places. My first thought would be that I need a different, longer mount but being new to this, I don't want to rule out that I'm missing something obvious. This is a problem, right? Looks like the previous owner at least had issues with the brake lever, it contacts the pipe before it bottoms out (the MC and system are empty right now though)

Mac did not make one exhaust system for a Special and another for a standard. The OEM did. As Phil stated, yours may have been mounted on a Special and you'll have to massage it a little.

[Eab]

Mac did not make one exhaust system for a Special and another for a standard. The OEM did. As Phil stated, yours may have been mounted on a Special and you'll have to massage it a little.

Turned out right, and easier than expected! Mounted the pipes to the rear footpeg bolts instead of the exhaust bolts. Allows it to drop maybe an inch at the back end, enough clearance to get around everything. Used some washers to space the pipe inward on the right side and gained a lot of space. The brake still barely taps the pipe when it's fully depressed, but once I've got the fluid in there and it's bled, I doubt the brake will be able to push down far enough to hit the exhaust. Lucked out!

[Eab]

I don't know Why I thought the rear MC might be Ok but it is NOT. Rebuilt the rear caliper but the MC piston cup mechanism is BONED. Got it soaking in brake cleaner overnight tonight, and a rebuild kit on the way, but it looks rust-fused, going to be fun finding a way to get it outta there without being able to tap it out from the opposite site. Got the retaining clip out at least, not so fun

update: dowel, mallet and a bench vise grip on the piston did the trick. Thank god they didn't use the same stuff from the pistons for the housings.