1976 XS650-C Project From Ireland

[TwoManyXS1Bs]

Hey, beano. Sorry, I've lost track of your activities. But, are the calipers OK?
If not, you may end up with another retrofit, different geometries, fouling up your master/caliper calculations...

 

[beano]

Hey, beano. Sorry, I've lost track of your activities. But, are the calipers OK?
If not, you may end up with another retrofit, different geometries, fouling up your master/caliper calculations...

Hi TwoMany, I removed the calipers this morning. One side has clearly just been rebuilt (found the yamaha packaging with the old pistons and seals inside). The other definitely needs new seals, but pistons and bores look to be fine. The good news is I found two new seal kits in dads stash of parts, so that's another thing off the order list at least.

 

[kevski]

You can get the master cylinder re-sleeved in stainless steel at past parts in Norfolk, i recently had a Z1000 one done it cost less than £60, also a quick turn around.

 

[Grimly]

My twin caliper master cylinder was a bit wooden after I'd done the front brakes overhaul, so replaced the m/c with a Deauville (Nissin) 5/8 which suited it perfectly. Lovely retardation now, without losing motion on the lever, and the lever's adjustable anyway.
I'd started with a smaller one of 14mm, and while the lever would have pitched me over the bars, there was too much lost motion for my liking, so going back up to a 16mm made all the difference - not as big as original, but just right for feel and stopping.
They're now better than they ever were from the factory, of that I'm sure.
The calipers responded really well to an overhaul and when reassembled I was glad to find very little play in them, unlike the old GS cylinders I'd been used to.

 

[5twins]

Yes, I was going to mention that the twin discs seem to work very well with the MC size Yamaha chose for the single disc. I don't necessarily agree with the ratio ranges 3M recommends either. While my experience is only with the later brake set-up, I found the same as Grimly - a MC small enough to be in the 3M recommended range gave excess lever travel. Slightly larger and outside his recommended range, but still smaller than stock, has worked better for me. Here's his chart with the single disc 650 sizes noted .....

 

[beano]

You can get the master cylinder re-sleeved in stainless steel at past parts in Norfolk, i recently had a Z1000 one done it cost less than £60, also a quick turn around.

Thanks for that kevski, I didnt know you could get them re-sleeved, however I'm also missing the fluid reservoir and cap too, so I think replacement is going to be the only way forward with this.

replaced the m/c with a Deauville (Nissin) 5/8 which suited it perfectly ......... going back up to a 16mm made all the difference - not as big as original, but just right for feel and stopping.

This is interesting, 16mm master cylinders seem to be quite available and reasonably priced too!! Does your bike have the twin opposed calipers installed yeah??

From the chart that would give around a 36:1 ratio which would put it at the "spongey" end of the threshold, but as 5twins has pointed out, the chart is just one mans opinion on the optimum........I just want a decent brake that will haul me up quickly and not lock up the front in the wet.

Yes, I was going to mention that the twin discs seem to work very well with the MC size Yamaha chose for the single disc. I don't necessarily agree with the ratio ranges 3M recommends either. While my experience is only with the later brake set-up, I found the same as Grimly - a MC small enough to be in the 3M recommended range gave excess lever travel. Slightly larger and outside his recommended range, but still smaller than stock, has worked better for me.

The stock 13/16 master cylinder is itself just outside the range on the chart, but on the firmer side at approx 22:1. It is however much closer to the described optimum range than the 16mm master cylinder which is approx 36:1.

Maybe I'm getting too hung up on the "ideal" and should be a bit more pragmatic. From a cost perspective alone the 16mm's can be found for much much cheaper than the 13/16's.

https://hvccycle.net/yamaha-reproduction-master-cylinder-hvc200109-735-25850-00-98/

https://www.xs650shop.de/en/brakes/1180/master-cylinder-75-76?c=118

I'd be open to giving the 16's a shot for sure, and Grimly seems pretty happy with his, but the 5.5mm difference seems like a big big change from stock........... I suppose I'd better get searching and see if I can find a couple of other positive reviews to confirm it before I pull the trigger. Thanks to the above for the contributions so far, I do appreciate it!!

 

[Grimly]

No, mine are stock single-piston each sliding calipers.

 

[beano]

No, mine are stock single-piston each sliding calipers.

Ah I see!! Mine has 2 pistons per caliper so that’s four in total that the master cylinder has to move. I think I’ve made my mind up with this and will likely opt for the larger one to be honest, the more I think about it the more it makes sense. I prefer having a firmer lever as my main bike is an R1, so I’m used to having instant power at the lever.

As it’s a bank holiday here in Ireland I managed to get a bit more time at this than I normally do upon my all too infrequent trips home.

I decided to pull out the fuel tank and have a look to see what it will need to get done. Inside wasn’t as bad as I was expecting but there’s still plenty to do. There has been a previous attempt at a tank liner, and it has not aged well.

As you can see from the pic, it has started to flake off, however the metal itself doesn’t look too bad. I have previously used POR 15 to line the tank in my FZR, and it worked quite well but I am unsure as to how to proceed with this as I do not know the composition of the tank liner, so not really sure how to go about removing it if anyone wants to chime in.

The next problem I encountered is both embarrassing and annoying in equal measure. I connected up a brand-new tacho cable when I was installing the gauges on Friday. Started the bike up and noticed there was no movement from the rev needle. Curious at this I decided to undo the cable from behind the clock and noticed no movement from the wire, so I undid the other end of the cable from the engine side and there was the end of my brand-new cable sheared off. Thankfully it was spinning around so at least I knew it wasn’t oil pump failure. I’m just pissed that I didnt put it in the back of the clock and test it before installing it.

So anyway, I removed the clock and played around with it for a while on the bench, sprayed some wd40 and contact cleaner in there, but its still seized solid. I’ve had a search around the site but can’t seem to find any threads on seized tachometers so once again, any advice is welcome.

And finally, when I was reinstalling the left-hand engine cover after servicing the worm gear, I noticed that the cover was sitting proud of the engine case, upon inspection it seems it was literally a case of trying to fit a square into a round hole!!

I'm assuming that Yamaha did a revision somewhere along the line and dad swapped the cover over for whatever reason. I suppose the easiest thing to do will be to put a radius on the corner of the cover to mate it properly with the engine side.

So that's that, a productive weekend was had, I'm happy as long as things keep moving.

 

[5twins]

I have about a 6" length of old speedo/tach cable with the squared off end I use for testing and working on the gauges. If I find a stuck one (which I have), I can usually stick this short cable part way in and put a small adjustable wrench on the square section not inserted, then turn it to break the part free. You can chuck this short cable up in a drill to spin and test the gauge, but I try spinning it by hand first in case it's frozen up like yours. I also do this to distribute any lube I put in them. Good news, you now have an "old" cable you can clip the end off of to make this "tool", lol.

 

[beano]

I have about a 6" length of old speedo/tach cable with the squared off end I use for testing and working on the gauges. If I find a stuck one (which I have), I can usually stick this short cable part way in and put a small adjustable wrench on the square section not inserted, then turn it to break the part free. You can chuck this short cable up in a drill to spin and test the gauge, but I try spinning it by hand first in case it's frozen up like yours. I also do this to distribute any lube I put in them. Good news, you now have an "old" cable you can clip the end off of to make this "tool", lol.

That's a good idea, I was thinking of doing something along those lines, just wasn't sure as I thought I could make it worse! I was having nightmares of being forced into disassembling the clocks so hopefully that will do the trick thanks.

 

[5twins]

Set the unit upside down and soak the area where the cable inserts with penetrating oil. Once it frees up, put regular oil on it and "work" it in by spinning it with your new "tool".

 

[beano]

Santa has been good to the xs!!

But for the next installment on my chronicles let’s talk fenders….

First things first, I really, really like the look of the stock fender and struts on the 76 model. I just think it’s classy looking and it’s something that I didn’t want to compromise on, so I just needed to acquire one. To this end I am very envious of ye guys in the states with access to such a vast amount of dirt-cheap, low mileage, rust free parts.

After spending a few weeks on ebay etc I quickly learned that there was no hope of me ever bagging a nice original front fender set up here in Europe that still had all its chrome, or didn’t cost what ye guys over in the states could get a whole bike for!!

So after changing my ebay search settings to “worldwide” it didn’t take long to find a variety of decent fenders from as little as $25. Things were looking good and I eventually settled for a clean fender with decent chrome and struts included for just $75, plus another $60 to ship, a bargain when you consider that a fender of similar quality here would fetch €300 easily.

It was only after its arrival that things started to get a bit odd.

I went out and attempted a trial fit on my bike, the first thing I noticed was that the mounts at the top of the fork leg wouldn’t line up, so with the front pair of holes secured the rear ones were out of line by about 5mm. Undeterred I proceeded by just tightening up the front holes and moving on. The struts were next and seemed to mount to the lower fork legs without incident.

Taking a step back to work out the top mounting and thinking I might be able to get away with just drilling a pair of new holes at the rear of the mount I noticed that the fender was very closely mounted to the front tire, so much so that I couldn’t even get my pinky finger in between. Grabbing a tape measure showed there was only approx. 10mm of clearance, something didn’t seem right.

It was from here that I decided that more research was required, which lead me to the following threads:

http://www.xs650.com/threads/never-before-seen-1975-forks-and-fender.52444/

​

http://www.xs650.com/threads/members-with-1972-1973-front-fenders-i-d-help-needed.52189/

​

http://www.xs650.com/threads/are-all-xs1-xs650-front-fender-interchangable.36218/

It turns out that the Euro models have a unique front end compared to the rest of the world, cross referencing the part numbers with the genuine parts books i acquired confirmed this.

As you can see from the pics below the first difference is the height of the fork brace mounts – 150mm tall for the US version and 175mm for the Euro version.

As described earlier, the hole spacing for where they mount to the fork is also different between the two items, 60mm for the US version and 50mm for the Euro version.

Swapping over these mounts is an option, though not as straightforward as I would have hoped as the spacing where they are riveted at the top of the guard is different.

The measurements for the US spec guard is approx. 82mm centre to centre horizontally and 57mm vertically.

The corresponding Euro values are approx. 73mm centre to centre horizontally and 42mm vertically.

There seems to be enough meat left on the euro mount to drill new holes, so this option is viable if i can find the right struts.

This brings us to our problem child, the struts……….

With the legs of the struts on the bench standing, the US versions are approx. 337mm tall to the centre of the strut.

As already established above, the euro fork mounts are 25mm longer than the US fork mounts, so the struts I need must be 362mm. This is an issue because with Euro spec parts come Euro spec prices and the cheapest decent set of struts I can find come in at €150 plus shipping.


https://www.ebay.co.uk/itm/Strebe-u...775455?hash=item2abb772a5f:g:jGoAAOSwJ6Vb6rEl

​

https://www.ebay.co.uk/itm/Strebe-o...096932?hash=item1cc0679064:g:Ts0AAOSwGoBb6rKJ

However, searches for struts of this length have provided interesting results, see post #10 in the link below.

WANTED Yamaha XS2 front fender or front fender support, Chain Guard And Seat.

From the above thread, the struts from an xs2 appear to be the right length, though the part numbers do not match so I don’t think they will just bolt on. More research is required to see if there is a difference, probably the bolt pattern, radius of curve etc.

So, I’m going to see if I can find the measurements for the xs2 struts and if they work out, and I can find a good pair cheap then happy days, in the mean time I will keep on the look out for a set of euro struts that are more reasonably priced.

Thanks for staying with me and happy holidays.

 

[MaxPete]

Very interesting Beano - who knew? I wonder why Yamaha manufactured different versions of such a mundane part as the fender stays (struts) for different markets?

....also - where’d’ya get those beautiful ‘76 style mufflers?

MerryChristmas!

Pete

 

[Norton7d]

Wow what a great response, you just cant beat the local knowledge that owner specific sites possess. Iv'e made some good progress I think with just working out where everything goes etc, the info in the posts above have really expedited the process so thanks to each and every one of you for the help so far.

So i started by printing out the wiring diagrams for for the headlight shell and began checking off the wires as i went along, it mostly corresponds to the diagram however i don't have an ignition switch and my tachometer has had the wiring removed, so i cant check them but i'm assuming they are correct.

There are some differences between the loom that i have and the wiring diagrams, the details of which i will describe below.

As you can see there is an extra red/yellow wire in the left hand switchgear (possible parking light circuit??)

There is a 6 wire connector for the tachometer in the left hand branch of the loom instead of the 4 wire connector in the diagram, this 6 wire connector corresponds exactly with the xs650b set up.

There is no 2 wire connector (L/R B) on the right hand branch,

There are 2 wires yellow and brown on a separate branch which originates from the left hand branch, possible front brake light switch??

I'm also assuming this 5 wire connector (located in the middle of the loom) is for the lamp checker unit which i do not seem to posess??

The orange and grey wires to the points/condensers i think are now redundant due to the electronic ignition.

Thanks again for everyones contribution so far, its been a real help i really do appreciate it, hopefully we will have her goin soon!!!

My. US 76 has the 4 wire connector coming out of the tach.
Im glad I saw this post, I didnt realize handlebar switch looms went into top hole of headlight, thats going to get crowded.

 

[5twins]

Yes, it seems to get crowded on most all the models. I re-route them into the larger lower holes.

 

[beano]

Just to follow up on the previous post about the seized tachometer, I took 5twins advice and cut off a piece from the broken cable and worked it with an adjustable spanner and some oil, boy that thing sure was stuck!! It eventually freed up anyway so thanks again for the advice.

Very interesting beans - who knew? I wonder why Yamaha manufactured different versions of such a mundane part as the fender stays (struts) for different markets?

....also - where’d’ya get those beautiful ‘76 style mufflers?

MerryChristmas!

Pete

Hey Pete, yes you would wonder, and it sure would have made my life easier, but now that I have my hands on the proper parts books (the holy books as I call them), things are becoming a bit clearer.

From cross referencing the part numbers it turns out that pretty much the whole front end: fork tubes, brake disks, calipers etc for the Euro 447 models was lifted from the RD350A

Edit: I got this wrong, the fork lowers for the Euro models actually cross reference with the early TX/XS 500's. Apologies for the mistake.

I've found a picture of an XS650 in the UK wearing an early TX/XS-500 front guard:

And a 74 TX-650 in the states that also appears to be wearing a 500 guard.

But for some odd reason the fender and stays for the Euro models are unique.......

As for where did I get the mufflers?? Would you believe me if i told you they were brand new? Well either way, that's a post on its own, I'll write it up later!.

 

[650Skull]

Santa has been good to the xs!!

But for the next installment on my chronicles let’s talk fenders….

First things first, I really, really like the look of the stock fender and struts on the 76 model. I just think it’s classy looking and it’s something that I didn’t want to compromise on, so I just needed to acquire one. To this end I am very envious of ye guys in the states with access to such a vast amount of dirt-cheap, low mileage, rust free parts.

After spending a few weeks on ebay etc I quickly learned that there was no hope of me ever bagging a nice original front fender set up here in Europe that still had all its chrome, or didn’t cost what ye guys over in the states could get a whole bike for!!

So after changing my ebay search settings to “worldwide” it didn’t take long to find a variety of decent fenders from as little as $25. Things were looking good and I eventually settled for a clean fender with decent chrome and struts included for just $75, plus another $60 to ship, a bargain when you consider that a fender of similar quality here would fetch €300 easily.

It was only after its arrival that things started to get a bit odd.

I went out and attempted a trial fit on my bike, the first thing I noticed was that the mounts at the top of the fork leg wouldn’t line up, so with the front pair of holes secured the rear ones were out of line by about 5mm. Undeterred I proceeded by just tightening up the front holes and moving on. The struts were next and seemed to mount to the lower fork legs without incident.

Taking a step back to work out the top mounting and thinking I might be able to get away with just drilling a pair of new holes at the rear of the mount I noticed that the fender was very closely mounted to the front tire, so much so that I couldn’t even get my pinky finger in between. Grabbing a tape measure showed there was only approx. 10mm of clearance, something didn’t seem right.

It was from here that I decided that more research was required, which lead me to the following threads:

http://www.xs650.com/threads/never-before-seen-1975-forks-and-fender.52444/

http://www.xs650.com/threads/members-with-1972-1973-front-fenders-i-d-help-needed.52189/

http://www.xs650.com/threads/are-all-xs1-xs650-front-fender-interchangable.36218/​

It turns out that the Euro models have a unique front end compared to the rest of the world, cross referencing the part numbers with the genuine parts books i acquired confirmed this.

As you can see from the pics below the first difference is the height of the fork brace mounts – 150mm tall for the US version and 175mm for the Euro version.

As described earlier, the hole spacing for where they mount to the fork is also different between the two items, 60mm for the US version and 50mm for the Euro version.

Swapping over these mounts is an option, though not as straightforward as I would have hoped as the spacing where they are riveted at the top of the guard is different.

The measurements for the US spec guard is approx. 82mm centre to centre horizontally and 57mm vertically.

The corresponding Euro values are approx. 73mm centre to centre horizontally and 42mm vertically.

There seems to be enough meat left on the euro mount to drill new holes, so this option is viable if i can find the right struts.

This brings us to our problem child, the struts……….

With the legs of the struts on the bench standing, the US versions are approx. 337mm tall to the centre of the strut.

As already established above, the euro fork mounts are 25mm longer than the US fork mounts, so the struts I need must be 362mm. This is an issue because with Euro spec parts come Euro spec prices and the cheapest decent set of struts I can find come in at €150 plus shipping.

https://www.ebay.co.uk/itm/Strebe-u...775455?hash=item2abb772a5f:g:jGoAAOSwJ6Vb6rEl

https://www.ebay.co.uk/itm/Strebe-o...096932?hash=item1cc0679064:g:Ts0AAOSwGoBb6rKJ​

However, searches for struts of this length have provided interesting results, see post #10 in the link below.

WANTED Yamaha XS2 front fender or front fender support, Chain Guard And Seat.​

From the above thread, the struts from an xs2 appear to be the right length, though the part numbers do not match so I don’t think they will just bolt on. More research is required to see if there is a difference, probably the bolt pattern, radius of curve etc.

So, I’m going to see if I can find the measurements for the xs2 struts and if they work out, and I can find a good pair cheap then happy days, in the mean time I will keep on the look out for a set of euro struts that are more reasonably priced.

Thanks for staying with me and happy holidays.

Hey beano, I don't post these days but i saw your fun and games with the guard stays and thought i would add a caution and some info that you may or may not have already found out.

I have some 73 Stays and tried to fit them to a 74-79 Standard guard. The bolt brackets that are welded to the stay were a different dimension between the 72/73 guard and the later 74-79 standard guard and also there was some difference in the stay width where it straddled the guard...............just a heads up to take some measurements and compare before buying.

The difference in length is due to having smaller diameter rotors means the calipers are mounted lower on the forks so the stays are longer to clear the caliper.

On the XS2 the stays are lower on the forks compared to the 73TX and later 74-79, why? who knows, but they made the stays closer to the caliper on the US and other countries, except Europe
US 72/7

Euro 75/76
NOTE; the smaller rotor on the early 74-76 brakes as well. Can be seen where there is a lack of spokes, (for the want of a better word), on the rotor inner

The difference in length is due to having smaller diameter rotors means the calipers are mounted lower on the forks so the stays are longer to clear the caliper.

Interesting about the difference in the actual guard mount hole dimensions

 

[beano]

Hey Skull, thanks for that, some great info in that post!! So that confirms what I semi suspected, that the XS2 stays wont fit my 76.

That leaves me with the following options:
Fit the US spec fender and stays as they are.
Purchase Euro specific stays.
Lengthen the stays I have by cutting and adding a slug.

Pics below are profile pics of the previously fitted guard and the US spec guard.

Would 10mm be enough clearance for the front tire?? Its hard to say if I would get away with it but there is a part of me that would chance it.......................

 

[Paul Sutton]

Nice picture data there from 650skull and Beano.

 

[Norton7d]

Yes, it seems to get crowded on most all the models. I re-route them into the larger lower holes.

I might do this but one of my switch looms is just a little short on the outer cover, so the wires show in the back of the bucket, vs seeing just the outer black cover.