1972 XS2 with 5k miles

The bike is titled/registered as a 1973 but the internet says the color scheme is 1972.
Yes it's a 72 XS2. The front brake is a tell. 1 year only for the disk carrier attached to the fork leg.
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Welcome and very sweet find indeed. Specimen's like that are getting more and more rare.
 
My girlfriend and I maintain and ride about two dozen vintage motorbikes ranging from pre-war to early 70's. So I have a pretty good idea as to what it will take to make this bike roadworthy.
This forum is the place to ask specific questions. There might be more than 1000 years of XS experience here. Welcome to the madness.
 
Update:

Bled the front brake and pumped a container of fresh brake fluid through the master cylinder and caliper. Seems to work okay pushing the bike around the garage, but I expect at least new seals might be in order.

Changed the oil, replaced the primary oil filter, and cleaned the secondary oil fillter. I'll change the oil again at 100 miles to check for weird stuff. Oil is cheap.

Torqued all head bolts to spec.

Adjusted the timing chain.

Adjusted valves. This was a bit confusing as Yamaha, Clymer and the internet all have conflicting information about proper valve lash. I went with 0.003" intake and 0.006" exhaust, but that's tighter than the 0.006" intake and 0.008" exhaust spec listed in the Yamaha XS2 manual. Would appreciate comments on this from someone knowledge about the XS2.

Checked compression: 150psi left and right (cold).

Set points gaps and adjusted points to achieve proper static timing. Discovered the advance mechanism arms have a tendency to stick open so cleaned and oiled those - - - but they still stick a bit.

Started the bike and verified dynamic timing is okay.

The right exhaust is smoking a little. Hopefully just sticking rings that will free up. I'll try some Sea Foam and see how it goes.

Replaced missing rear brake switch.

Went over the whole bike front to rear to check for loose fasteners.
 
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FWIW- historical references on subject
 

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Presumably the intent is to have a std. clearance through rocker arms on the cam as one checks valve opening in degrees (36* BTDC In, 68* BBDC Ex), etc.
 
Yes, the advance rod needs servicing. Very commonly overlooked maintenance item on these bikes. Many haven't been touched since they left the factory. The shop manual recommends a grease with Moly in it. When you pull the advance rod out of the cam, you'll see the bushing in each end has grooves cut into it's I.D. .....

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Clean them out and pack them full of fresh grease .....

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This will provide the rod with a reservoir of lube for several years to come. This service isn't something that needs to be done often, maybe every 5 years or so, but it does need doing.
 
I finally got a free weekend to test ride my bike. It's still not registered, so I put it in my van and hauled it to my preferred locatoin for testing bikes that aren't legal - - - a giant tech campus parking lot that's empty on weekends.

The bike seems to run and shift fine, but I immediately noticed some clunking from the front end.

When I returned home, I found this thread about worn or missing rubber pieces that act to shim the disk carrier to the hub causing this sort of behavior. So I'll check that.
 
Reviving this thread after a few months hiatus. . . .

I rebuilt the front brake caliper (new seals and EBC brake pads), installed a new period-looking master cylinder and bled the system with DOT 4 fluid. I'll replace the original brake lines with a modern line in the future, but that wasn't an immediate priority.

I took the bike for a 50 mile test ride today and everything seems okay, but the front brake is noisy - - - at least without earplugs which I normally wear but did not today because I wanted to be able to hear weird noises. Is the front brake noise just the nature of the beast with the weird 1972 brake setup? The front wheel spins as expected with a little caliper drag with the bike on the centerstand.

From this morning's ride. The Honda is my girlfriend's '67 CL77.

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Purchased last weekend from the original owners family. Running and very low miles but some "shelf wear" from being stored in an unheated San Francisco garage. These are as purchased pics. I'll post additional pics with the accessories removed in another post.


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Welcome! Nice survivor.
 
Should not be any noisier than any other front disk brake. Other than a clunk when the rotor housing gets loose. But your other thread shows you have it tight. What kind of noise are you hearing?
 
Should not be any noisier than any other front disk brake. Other than a clunk when the rotor housing gets loose. But your other thread shows you have it tight. What kind of noise are you hearing?

Sounds like brake pad / rotor contact noise, but a bit louder than normal. Maybe some kind of resonance amplification? Although most of my bikes have drum brakes or very modern disk brakes, so it could be a little paranoia on my part.
 
Sounds like brake pad / rotor contact noise, but a bit louder than normal. Maybe some kind of resonance amplification? Although most of my bikes have drum brakes or very modern disk brakes, so it could be a little paranoia on my part.
Probably the latter, which IMHO is normal when you throw you leg over a bike that's 50+ years old and has been sitting. If every thing is tight, and the brakes are applying and releasing as they should, it could just be the EBC pads. I believe I put EBC's on my Harley. They stop fine but are noisy.
 
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This pic shows an original brake pad on the left and an EBC brake pad on the right. Note the difference in tab length. When I first tried installing the EBC pads on my XS2, I discovered that the longer tab on the outboard side of the caliper interfered with the fork slider. So I cut the tab down to match the tab length of the original pad. Problem solved.
 
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