Custom Fighters - Custom Streetfighter Motorcycle Forum banner

1974 TX650 build.

9653 Views 104 Replies 10 Participants Last post by  toglhot
I've been building bikes for the last 50 odd years. This is my latest project. I bought it about 12 months ago as a non goer. It was missing a few bits, badly rusted steel bits, oxidised ally bits and the last owner apparently only had a hammer and chisel. Chain had come off at some stage and wrecked the crankcase, compression was down to 65 and 80 psi. Auto advance was a bodged up homemade job about 60 degrees out. Carbs were gunked up along with oil filters. Plan was to Cafe it. I do everything myself: Welding, painting, machining, polishing, anodising, electrical, mechanical, upholstery and so on. I'm retired so plenty of time. This project will be my last, I can't ride anymore due to chronic RA, so the project will continue as long as I can. Here's some pics of what I started with and where I'm up to with the build.

Attachments

See less See more
10
  • Like
Reactions: 4
81 - 100 of 105 Posts
This is a new brake divider I machined up to replace the original. The original hoses were rotted, so I replaced them and did away with the two steel tubes that connect the hose to the calliper and the hose from the master cylinder to the divider. Unfortunately, the new hoses have the banjos on the same plain requiring the lower hose to be twisted through 90degrees to connect to the original divider, so I machined a new divider to get around the problem. The lower hose connects at the rear of the divider, as does the brake light switch. The top hose connects to the side of the divider.

Attachments

See less See more
4
  • Like
Reactions: 3
A few hours is all it took - it's just a pile of bits that once was an almost complete bike now, just needed tyres and the seat covered. Going to be a big job polishing all those bits again, any volunteers???

A couple of mods on the frame to do: Remove the coil and flasher mounts then repaint along with tank, guards, seat, trees and a few other bits. Not sure what paint to use this time. I used acrylic lacquer last time, but spilt some petrol on the tank and it stained it. Painted heaps of tanks with acrylic lacquer before but never had this problem, either the paint is different or the petrol is. Don't really want to repeat the exercise.

Attachments

See less See more
5
  • Like
Reactions: 1
Have you considered using a 2K clearcoat? A decent one thats genuinely 2K should be impervious to petrol regardless of changes in ethanol content.
Here’s the process used making the air filters. I took sizes of the first filter I made and replicated them to the second. This time I took lots of pictures to outline the steps in making them. I cut a 15mm slice off the 101.6mm lump of ally and turned down one end to 97.4mm, then cut a piece of 1.7mm sheet to around 111-mm in diameter, stuck them together and bashed the overhang until there wasn’t one. I have to use my left hand now, as the right elbow complains. Sound easy, but it’s not, out of every 10 strikes, I think I miss about nine.
Once formed, I mounted it in the four jaw, and turned the overhang down to 3mm, then smoothed out all the scratches and what not with sand paper, finishing off with the random orbital sander with 240 grit.

Attachments

See less See more
10
  • Like
Reactions: 2
Next, I mounted the 15mm slab in the three jaw using the turned down area and drilled through with a 25mm bit, machined the outer diameter to 101.4mm, machined out the centre leaving a 2mm wide lip on the periphery, 3mm deep, then bored out the 25mm centre hole to 57.3mm to fit the 57.4 mm carb bell mouth. .10 mm proved a little tight, .07 would have been better I think.
I flipped the slab over and mounted it in the four jaw, then spent a couple of hours trying to centre the damn thing, then turned down the inner mounting ring so its 8mm wide and the flat body of the filter 2mm thick. Final step, turn down the inner mounting ring so its 9.8mm deep.
The cutting tool was then centred., spot on, and used to scribe a line across the back of the centre mounting ring. After removing from the chuck I found the centre point using a calliper, centre popped it, mounted it on the mill and drilled the centre pops with a 4mm bit, then mounted it on the pedestal drill, centred the holes and tapped the 4mm holes with a 5mm x .8 tap. The plate was then turned on its side, and drilled and tapped in the centre of the centre ring at 90degrees to the other two holes on the face.
The piece was mounted in the three jaw again and using 240 grit any cutting ridges were smoothed over, then both plates were polished.
The knurled securing nuts were turned up from a piece of 20mm stock, tapped 5mm and then knurled using the scissor knurler. These were mostly done by eye, so won’t be absolutely identical. You’d need a calliper to pick up the difference though, so good are my four eyes.

Attachments

See less See more
10
  • Like
Reactions: 2
The carb body was mounted in the three jaw and a file used to remove the ridge at the beginning of the bell mouth. The face of the bell mouth was pretty rough, so I took the time to smooth that with some emery. The turned piece was located over the bell mouth, the assembly was then stuck in the vice and pressed into place.
The lead into the bell mouth is flat, so not a perfect shape for induction. You can recess the filter lower on the bell mouth, creating a bit of a lip on the outer periphery of the bell mouth to improve induction, but realistically the improvement in induction wouldn’t be worth the time.
Both filters fit well and the hoses from the fuel distributor block lead over the filters nice and neatly. Happy with the outcome, except the inner knurled nuts are a little difficult to get to, probably due more to the fact my fingers are fused, but I can turn them with a little bit of messing around, better still, use the wife, her fingers aren’t fused. I’ve yet to get some perforated sheet metal to replace the stainless crap I used to keep the foam in place.
Tire Automotive tire Motor vehicle Wheel Automotive design
Tire Automotive tire Motor vehicle Wheel Automotive design

Attachments

See less See more
10
  • Like
Reactions: 3
Once again a very nice job you did there. respect !!!!
Slaved away today - making a clutch slave cylinder. I made it so it sits in the left cover, protruding through the clutch screw actuatorr hole. I managed to get the tolerances better than the caliper tolerances: The bore is dead on 25mm, the piston dead on 24.97, a really nice fit.

I couldn't find any seals similar to the caliper seals, but found a hydraulic pressure seal and dust seal, but I have to find a 25 mm internal circlip before cutting the circlip groove. I also,have to drill a couple of holes in the collar to suit the holes in the side cover, then bore out the hole in the cover to 30mm and drill out the M5 securing threads. Once done two M5 Allen's will bolt through the outside of the cover, holding the slave cylinder in place.

I did make one mistake, got carried away on the lathe and cut the collar down to 18mm, that only leaves a 6 mm threaded hole in the collar of the slave cylinder. Hopefully this may work as the screws are really on locating pegs.

Before modifying the side cover I'll order a hydraulic hose. Not sure what size master cylinder to get, but I'll try the slave out on the 17mm braker master cylinder first, that should give a clue, unless of course, someone here knows what size master to go with the 25mm slave for a nice light clutch pull: Fused fingers so grip isn't the best.

I'm hoping to find a pair of matching radial clutch/brake master cylinders.

Attachments

See less See more
10
  • Like
Reactions: 2
Slaved away today - making a clutch slave cylinder. I made it so it sits in the left cover, protruding through the clutch screw actuatorr hole. I managed to get the tolerances better than the caliper tolerances: The bore is dead on 25mm, the piston dead on 24.97, a really nice fit.

I couldn't find any seals similar to the caliper seals, but found a hydraulic pressure seal and dust seal, but I have to find a 25 mm internal circlip before cutting the circlip groove. I also,have to drill a couple of holes in the collar to suit the holes in the side cover, then bore out the hole in the cover to 30mm and drill out the M5 securing threads. Once done two M5 Allen's will bolt through the outside of the cover, holding the slave cylinder in place.

I did make one mistake, got carried away on the lathe and cut the collar down to 18mm, that only leaves a 6 mm threaded hole in the collar of the slave cylinder. Hopefully this may work as the screws are really on locating pegs.

Before modifying the side cover I'll order a hydraulic hose. Not sure what size master cylinder to get, but I'll try the slave out on the 17mm braker master cylinder first, that should give a clue, unless of course, someone here knows what size master to go with the 25mm slave for a nice light clutch pull: Fused fingers so grip isn't the best.

I'm hoping to find a pair of matching radial clutch/brake master cylinders.

Again very nice detail work. I would also like to have time for such awesome work again. Simply cleanly implemented.
I had a small fuel filter between the petcock and the fuel ditributor block on the previous dístributor build, but that proved a little difficult to remove and replace, there not being a lot of room. I also found the new pancake filters were hard to get the rear plate off as the distributor block got in the way, so, back on the machinery.
This time I machined a thinner block and positioned it further back on the battery cover, allowing the rear filter plate to be removed a little easier. I also replaced the small fuel filters with larger, 90 degree filters, but positioned them between the block and the carb. Looks neat and is eaier to replace.

Attachments

See less See more
5
  • Like
Reactions: 3
I had a small fuel filter between the petcock and the fuel ditributor block on the previous dístributor build, but that proved a little difficult to remove and replace, there not being a lot of room. I also found the new pancake filters were hard to get the rear plate off as the distributor block got in the way, so, back on the machinery.
This time I machined a thinner block and positioned it further back on the battery cover, allowing the rear filter plate to be removed a little easier. I also replaced the small fuel filters with larger, 90 degree filters, but positioned them between the block and the carb. Looks neat and is eaier to replace.

Oh man !! I can only say it again I like this attention to detail !!!!
Slaved away today - making a clutch slave cylinder. I made it so it sits in the left cover, protruding through the clutch screw actuatorr hole. I managed to get the tolerances better than the caliper tolerances: The bore is dead on 25mm, the piston dead on 24.97, a really nice fit.

I couldn't find any seals similar to the caliper seals, but found a hydraulic pressure seal and dust seal, but I have to find a 25 mm internal circlip before cutting the circlip groove. I also,have to drill a couple of holes in the collar to suit the holes in the side cover, then bore out the hole in the cover to 30mm and drill out the M5 securing threads. Once done two M5 Allen's will bolt through the outside of the cover, holding the slave cylinder in place.

I did make one mistake, got carried away on the lathe and cut the collar down to 18mm, that only leaves a 6 mm threaded hole in the collar of the slave cylinder. Hopefully this may work as the screws are really on locating pegs.

Before modifying the side cover I'll order a hydraulic hose. Not sure what size master cylinder to get, but I'll try the slave out on the 17mm braker master cylinder first, that should give a clue, unless of course, someone here knows what size master to go with the 25mm slave for a nice light clutch pull: Fused fingers so grip isn't the best.

I'm hoping to find a pair of matching radial clutch/brake master cylinders.
In terms of deciding on what size of master cylinder you need for a "nice light pull", its a ratio of the force required to actuate the clutch, vs the force at the lever, combined with the volumetic transfer. Firstly - how much force is required to operate clutch in N or Kgf ? (you'll need to figure out some way to measure this if you don't already know it) then, what's your desired "pull" in N or Kgf? the ratio between these two numbers is your starting point. Then what throw does the TX clutch need 5mm ? 6mm? understanding the throw gives you the volume of oil the master needs to transfer.
The pressure (force / area [N/mm2] ) generated by the master in simple terms can be calculated by calculating the ratio between the distance from the pivot to the centre of the lever (where your fingers will pull), vs the distance from the pivot to the centre of the master cylinder (i.e for example ratio of 10:1 Force at cylinder = 10x force applied at the lever, divided by the area of the cylinder.
However.... the stroke (and hence the volume transferred) will be divided by the same ratio.
So if the lever travels 50mm (measured at mid point) with a 10:1 ratio, the master piston will travel 5mm and the volume will be 5mm x the area of the piston.

It might have been easier to start with a known master cylinder, and then decide on the size of the slave... but given the time and effort you've put into making the slave, you'll need a spreadsheet to deal with variables, so you can plug in the size of the available slave cylinders, which this should give a good approximation of the resulting "pull" for different options. if you want a hand with that, let me know.
See less See more
Talk about overthinking it! The slave was made to the maximum size the cover could accomodate, 25mm. I have an extended lever in the left cover, which provides a 1.5 to 1 ratio with the lever. A 13 mm master is the smalest I can find, and that would provide an almost 2 to ratio - by size. As soon as I get a hose long enough, I'l hook the brake master up to the slave, which wil provide, roughly, a 1.5 to 1 ratio, again, by size. and I'l see how that goes.
Now the bike is almost finished, just needs the seat covered and tyres, so I put on my glasses and cast a critical eye over it. Story of my life – never, ever happy, and what do you know, I found a few things I’m not happy with, so, I can start making parts for it again, whoo hoo!. First up was a new spin on filter/cooler. The current one totally underwhelms me: hoses look untidy, the spin on filter mount looks too blocky, so, that went in the bin. One of the screws holding the mount to the engine bracket was a bit hard to get at, so, the right engine mount went in the bin. The cooler bracket is just plain terrible, didn’t like the mounting method nor the look of it, plus the rubbers I felt were too small, so that also went in the bin, along with the left engine mount.

So, back to work: first up was a new spin on filter mount, I put a little shape into this one: rounded the edges, turned a cone on top and pressed the inlet spigot into the side of the mount, so the outlet hose from the front of right engine cover is only around 4’long and attaches to the inlet spigot of the spin on mount on the side, just in front of the engine mount. Much more neaterer!

Next came some new engine brackets. The spin on mount is still mounted in the same manner, just set further back, so, the engine bracket protrudes further back, almost touching the engine case. This allows the rear allen head that was hiding behind the down tube to be moved further back, so now it is to thebrearnof the downtube and thus easy to get at.

Next came the cooler mount, the original I made was a piece of 3mm ally, bent at a right angle and bolted to the front of the engine brackets via four allen heads. Didn’t like that, so I extended a goose neck on the front of the engine brackets out about 30mm and drilled and tapped holes in top for mounting the cooler bracket.

The cooler bracket, is now just a flat section of 3mm ally, with larger holes drilled to take bigger, thicker gromets and is secured to the top of the engine mount goose neck protrusions via four stainless button heads. To mount the cooler to the bracket I spun up four threaded T nuts that are inserted into the gromets from underneath and the four long bolts secure the cooler to the top of the bracket. The T nuts prevent the gromets from being squished too much.

Now I just have the one long hose over the engine bracket connecting the cooler outlet spigot to the right engine cover. A hose connects the spin on mount spigot on top to the inlet on the cooler. I’ll retain the black rubber hoses as I don’t like the look of braided hose: to silvery and hard to keep clean down there with all the road debris and the black hose is a little less intrusive.

Attachments

See less See more
10
  • Like
Reactions: 2
I managed to drop the seat, so had to strip and straighten it, the calipers crinkled in a couple of spots, must had dropped some brake fluid on them, so I also stripped and repainted them. 2k paint, so I'll wait a couple of weeks before taking it in to get covered.

Attachments

See less See more
2
I was going to plumb the read valve engine breather into the pancake filters, but didn't like the idea of breathing sump gasses into the inlet, so, I made this catch can.

Not quite finished yet, I rushed it toward the end to see what it'd look like, happy with the result, So I'll probably build a neater one, with a few changes of course.

Matches the pancake filters, but almost unnoticeable

Attachments

See less See more
6
  • Like
Reactions: 1
It fits in very well. As always, your stuff is great!
So, I finally settled on a catch can design and built it. The first one was simply too big, creating mounting problems, so that was binned. The final one is made of 42mm tube with four baffles. Instead of welding the baffles inside of the tube, I fixed them together with a 4mm screwed and peened the end so it wouldn’t come apart, the baffle cartridge was then pressed into place resting on top of the intake tube so it won’t float around. The intake tube stretches across the diameter of the 42mm tube and has three exit holes underneath. For the blowby gas to escape it has to exit via the four baffles and finally through some stainless mesh before exiting through the air filter on top, set between the two carb filters.

I’ve gone with a remote empty point via a tap connected to the catch can by a rubber hose. The filtering medium inside the can is replaceable via the top plate secured on top by four 4mm stainless allens. The can is mounted to an aluminium bracket by two rubber gromets and two threaded T nuts to stop the gromet from being squished too far, then fixed to the right, rear engine bracket.

Mounting the can proved a little troublesome: behind the motor over top of the swing arm pivot is the only place I could find to mount it. To make it less noticeable I painted it black and welded an outlet on the side so I could mount the final filter between the two carb filters. It is only a small catch can with around 220ml capacity, that’s in total of course, realistically only around 100mm under the baffles. If it proves too small, I can fit a larger container under the swingarm connected to the catch can outlet by a rubber hose.

It’s very busy in this are area now, two carbs, three filters, catch can, fuel distributor block, making it a little difficult to remove the air filter caps.

Attachments

See less See more
8
  • Like
  • Love
Reactions: 3
Here it is, another fuel distributor block - number four. Just couldn't help myself.

I moved the inlet spigots closer together, milled a step at the front, round off the edge either side and mounted the block in the battery clamp holes, so it sits further back than it used to, thus giving more room to get at the air filters.

But, the old mounting holes are now visible, I'll address that later on.

Fuel filters are easy to get at, and a bit more obvious than I'd like, but, they are the only 90 degree filters I could find.

No more fuel distributoer blocks though, everywhere I look in my workshop, there seems to be an unused one sitting around looking for a home.

Happy with results now: Looks good, I can get to everything reasonably easy and I have somewhere for the engine blowby gasses to go, and I'm not feeding blowby particulates into the intakes.

Attachments

See less See more
5
  • Like
Reactions: 3
A little neatening up under the tank.
I had the cable splitter between the top engine mounts, difficult to get at and it was a little busy in there with two wiring looms, throttle cable splitter and clutch cable. So, I made a small bracket to hold the splitter on the outside of the left engine mount. It is now held securely in place, instead of just flopping around.
While I was at it, I attached the clutch cable to the right side, top engine mount via two small P clamps.
The cables that came with the VM34s had a curved stell tube which locates inside the top adjuster. This puts the cable in the way of the petcocks when removing/replacing the tank. To remedy, I made two new cables, minus the curved tubes and routed them,over the backbone of the frame.
The cables clear the petcocks now and have just a slight curve to the carbs.

Attachments

See less See more
5
  • Like
Reactions: 3
81 - 100 of 105 Posts
Top