Discussion in 'The Garage' started by DaveO, Jul 21, 2018.
Not much progress but I've stopped while I'm ahead. I hate coming back to a problem.
Looks good Dave - stick at it!
Question Dave - (and you may have already stated the reason - which I missed) why would you discard the second disc? Many folks over here would give their eye teeth for that set-up.
I know, believe me, I know about the increased unsprung mass - but frankly, it looks cool and was very uncommon on a 1970's bike in North America.
In fact, I think that the only bikes that had doubles discs here were the Suzuki GT750 Water Buffalo (you know it as the Kettle) and the early Honda Gold Wing (1975-on). Even the mighty 903cc Kawasaki Z1 had a single disc up front and a drum in the rear.
The black wire with the split ring crimp you show in post #31 is the main ground wire for practically everything connected to the harness that needs a ground. Best you connect that up. Originally, it mounted on one of the coil studs, trapped between the coil and frame (left coil, rear stud) .....
@5twins Thanks very much for that.
Very much appreciated.
The brakes were completely jammed on. The brake lines were the original fittings so would need replacing. There's four bits of brake line, plus a splitter which incorporates the brake switch. Then there's some steel pipe (which was OK but the fittings were a bit rounded, I would have cleaned them up).
So I started in on the getting the callipers apart. For that year the calipers have pucks on either side and when you pump to free the calipers, one side pops out and the other side stays put. I tried holding one side in with a clamp but couldn't find anything to fit. So, I started in on the other side (a little wiser now) and cobbled some bits of mild steel and threaded bar to hold each puck in in turn.
That's when the master cylinder started leaking badly. I have a 1975 xs650B with a Nissin 13/16" bore front master cylinder. There's a previous thread from about five years ago from someone else now discussing this. Seems like the 13/16" rebuild kits aren't available. So now I'm "in" for a new master cylinder and still have two half disassembled / half jammed calipers.
By now the cost of rebuilding both sides in the original set up was starting to rack up. I was going to have to buy bits for two complete sides. Just the shims that go behind the disk pads are £15 a set. And I was getting nowhere fast. I thought I would rebuild just one side and but was now going to have to buy a new master cylinder (or risk buying second hand and refurbishing that). I thought that I could refurbish and spend out on the two disk setup some time down the line.
The catch 22 was if I buy a caliper and use it on one disk I either buy something that is too big for one disk and will be later too small for two, or vice versa. I either end up with an incompatible system or more expense down the line.
Everyone here seems to replacing oversized master cylinders with smaller "pit bike" versions and installing cheap straight through brake lines. That settled it for me.
@5twins advised on the technicalities Early (1974 / 75) late (post 1977) brake calliper compatibility concerning most standard stuff being oversized in any case, and it was decided.
Later I found Yambits did a suitable RD125LC brake lever and cylinder (with the required smaller bore) for about £50. (Brand new. Bargain) (And by now my eyes were turning square at looking at Chinese websites.) and later still I found they had a remanufactured 75 caliper. £105 for the complete calliper, banjo bolt, crush washers, brake pads and shims.
It all sounds very complicated in hindsight.
I still have all the bits.
Well, there ya go. These darned things can become quite complex indeed!
Probably didn't help that I was busy editing while you were reading. LOL
I was up early this morning so spent a couple of hours in the garage. I did a bit of a tidy up and thought I'd drain off the old petrol from my tank and also take a look at why my petrol taps weren't delivering any petrol.
Levered out the rubber washers carefully but found the holes weren't round anymore and had little bits of sprue. Cleaned up the taps as best I could.
I put a punch through each hole and trimmed off the sprue with a Stanley Knife blade. (box cutter?) I re-assembled the taps and they felt much better at least. They seem to hold and pass air but I've not tried petrol yet.
I've a feeling I'll be re-visiting these but not unless I can't help it.. https://www.wemoto.com/parts/picture/np-xs650nonvac
Indeed - for such a simple device, the petcocks can be surprisingly troublesome.
These look genuine
You can do a forum search on "whizzer valve" for more info, like this:
I've got all the bits for the front brake now. The replacement banjo bolt came this morning. I had two 1.0 bolts but I found I needed one 1.25 and one 1.0. The Master is 1.25 as its off an RD125. Caliper fitting is 1.0 as its for an XS650. Its all fitted and ready to bleed.
I was really concerned about fitting the carbs. I mean, I've already had to file things and measure stuff and dread of dreads … solder. Everything I've soldered before has been a mess.
But even that has gone OK. Practice makes perfect. I've had a fair bit of practice now. I tried several pairs of pliers, junior hacksaws and a cold chisel and hammer. Finally I researched and then bought … Ta dah, parrot-nosed cutters. My God, cutting cable now is a doddle. After a few practices cutting scrap I can even cut the outer to a nice neat, straight end. So the carbs are fitted. I realised at the last minute that the metal outers on the carb boots are not going to fit and neither are the boot clamps. So my girlfriend was texted this afternoon from work. "Can you go to …. and buy me two 55mm Jubilee Clips?"
Called back. "Yes, they really ARE called that. No, its not a wind-up. I'll send you a photo. About four pounds."
I do have a problem. The cable is short. There is no adjustment left. My fear is that when the bars are turned once the bike is running it'll lift the throttle. I'll wait and see. With my newly found confidence in soldering it'll be a five minute job to knock up a new inner.
My head-scratcher now is how to make the fuel lines fit. There doesn't seem much room in there to make it all fit and keep everything flowing downhill. I need to fit in a T-piece (to match 5mm with 8mm) and I'd like a fuel filter but there will have to be two it they are fitted on the 5mm, tank side. Every extra piece is another straight bit. :-(
@gggGary said earlier,
"I like to work on mechanics but when things don't go well or I'm getting tired, I'll switch to cleaning rags and polish. Many times I catch and correct "little things" while cleaning. Shiny bits also encourage further work and the urge to get 'R going."
Actually he's right. Its very difficult not to wipe a bit of muck off here and there while you're thinking.
Now what I need is a t-piece, sintered fuel filter with two 5mm "ins" and one 8mm "out". A short squat one.
Oh, and I've bought a battery. Its on change. So, I'm committed.
I hate to say it but I think I'd just put a new throttle cable on it Dave.
I have had that situation where the throttle opens up when you turn the handlebars - and BELIEVE me - it is not fun.
I nearly rear-ended a Windsor Transit bus one time. I could see the dirt on the bugs on that buses bumper and it took several minutes to calm down after that.
Might you consider a single outlet breather from a later model? To save on available space?
@MaxPete The cable length is fine it's the inner that has ended up slightly too short so I'm at maximum (let out) adjustment. If I move the bars from side to side nothing moves at the carb end. It's just that I'd like that familiar bit of wiggle at the throttle end. Is there a standard cable that is mentioned in the long thread on EX500 carb mod? I mostly see modifications.
@weekendrider , thanks for that. I think I can make it all fit with what I have. But that's the sort of knowledge that make this site so brilliant. The new fuel pipe I've bought is shiny and plasticky and seem reluctant to form tight bends without kinking. The old stuff is rubbery and more flexible. Its in great condition actually for being so old, so I think I'll use some of that on the tank side.
PS - I was in the garage this morning before work. So that's a first.
Ahhh hah - you’ve caught the ailment!
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