1974 XS/TX650 rebuild

[th62]

And the rear rim, came out better than I expected. I used an air belt sander to try and even out the area between spoke holes, doesn't look too bad now. It has a couple of damaged bits still evident which I'll try and resolve with a nylon fibre wheel. I may just use these I think, will look good once spoked up to polished hubs with polished spokes. I'm polishing the exposed edges on the aluminium wheels also, once I've painted them and exposed the polished edges I'll compare them. Still not keen on a fat 16" at the rear though.

[Rikk]

Nope, haven't looked into any of the commercially available electronic ignitions. Haven't looked into any of the commercially available anything actually, too damn expensive and this is supposed to be a budget build. Although, if I looked at how much I've spent so far, it's hardly 'budget'! I have looked at building a hall effect system, I have all the electronic parts, just haven't got around to building one yet, one day. Plus, I tend to like mechanical things in case you haven't noticed.

I don't blame you one bit. No sense replacing what works or what you can make for much less money.

Those wheels look great, You are the only one that will notice anything wrong with them. That bike has way to may other cool things going for one to be distracted by minor pitting in the wheels.

[Rikk]

Ok, that's the end of this thread as I can't post anymore pics. Admin have been less than helpful so I'l cease posting here. If you are so inclined you can continue following the build at A long, long project. | Page 11 | Yamaha XS650 Forum....

Well that stinks...

By the way, this is a cut/paste of the post I received in an email notification, but was not shown here when I clicked on the link.

[asterix]

Rikk , thank you for the cut/paste of TH62 thread . We will follow him on the other forum.

[th62]

Retry: Synced the carbs and checked the PMA today. Bike runs beautifully now, idles nicely, revs cleanly, no spitting or hesitation. PMA/reg/rect output is 14.6 volts, so happy with that as well. Timing is spot on on both cylinders, so the single points cam also works well and the filter and cooler deliver a good oil supply with no leaks. Fancy that, all the engine mods worked as planned! This is my homemade manometer I use for syncing, super easy to use, gives a good, stable reading.

Now it's back to cycle parts. I was going to spoke the wheels next, but can't get any stainless spokes for the rear wheel, so I'll have to work on something else: I've been thinking of hunting around for a clagged 650 motor, I'm missing working on motors already.

Sound is a bit strange though. Trust me though, without mufflers this thing sounds great!

[th62]

Retry: Synced the carbs and checked the PMA today. Bike runs beautifully now, idles nicely, revs cleanly, no spitting or hesitation. PMA/reg/rect output is 14.6 volts, so happy with that as well. Timing is spot on on both cylinders, so the single points cam also works well and the filter and cooler deliver a good oil supply with no leaks. Fancy that, all the engine mods worked as planned! This is my homemade manometer I use for syncing, super easy to use, gives a good, stable reading.

Now it's back to cycle parts. I was going to spoke the wheels next, but can't get any stainless spokes for the rear wheel, so I'll have to work on something else: I've been thinking of hunting around for a clagged 650 motor, I'm missing working on motors already.

[th62]

Not sure if I posted this mod before, just in case, here it is a remote spin on filter and cooler mod.

This took a lot of work, I had to modify the right side engine cover, machine up a new cover for the now gone strainer, machine a spin on filter mount, fabricate some new engine mounts to hold the mount, fabricate a mount for the cooler, machine up a few stainless fittings for the mod, plus a few other bits and pieces.

I drilled and tapped the front of the sidecover. I hate jobs like this, there's always the fear of stuffing it up and ruining a part, but, all went well: drilled out the oil pump gallery to 10.8mm, tapped it to M12 x 1.25 for 40mm to cover the gallery to the old oil strainer, countersunk the top of the hole to allow for an O ring and inserted the stainless spigot I turned up, looks quite alright.
Whilst I had the cover off, I removed the kickstart mechanism and turned up a couple of bungs to cover the hole.

Next I binned the strainer cover and machined up a new one, which I think looks a lot better than just screwing a right angle, screw in fitting on the original part. Took a bit of doing this part as the outer side had to be angled to follow the angle of the side cover. Rather than use an ugly screw in fitting, I spun up a stainless barb and shrunk it in place.

Next came the spin on filter mount. I made this from a lump of 25mm ally, shaped it to the desired shape, drilled and tapped the side for mounting screws, then mounted it in the lathe to machine the oil gallery recess, once done I drilled a central hole for oil intake and a second hole through to the recess for the output. I then spun up a threaded piece on which to spin the filter, shrunk fit it into the housing, turned up a stainless, threaded barb, screwed it into the spin on filter threaded piece, sandwiching the filter mount between. There was insufficient space for a screw in output barb, so I spun up a barb for an interference fit and pressed it into place.

For my next trick I fabricated some new engine mounts on which to mount the filter mount and oil cooler. The engine mounts were basically the same as the original ones I made, the right has been extended downward around 25mm for the filter mount and both drilled and tapped at the front edge for mounting a cooler bracket.

The cooler bracket is just a piece of 3mm ally bent at a right angle so the cooler mounts on top. I had to cut some 10mm ally tube to fit between the cooler mounting fins and recess the mounting bracket holes a little so I could install some rubber grommets to insulate the cooler from vibration. To hold it in place I cut some 6mm bolts to size and spun up some threaded positive stop, ally T nuts.

Last of all, I polished everything - of course!

All the parts sat around for a while while I awaited the arrival of some AN fittings for the cooler. Damn expensive these things, $60 for two. When they arrived I mounted everything and linked everything with rubber hose. Looks quite all right, not overly visible.

Quite a big job this one, but all worked out well in the end and the system worked well when I started the bike.

[th62]

Stock, the lube system works like this: The motor is wet sump, so oil is contained in the sump. The oil pump is is mounted in the right side cover and linked to the sump via large gallery across the motor. So, oil is drawn from the sump, into the pump and out through a 10mm gallery toward the front of the right side engine cover. The gallery is bunged at the front of the cover and another gallery drilled at a right angle, just before the bung delivers oil to the right side oil strainer behind the round cover on the right side engine cover, the oil is strained and then fed through a small 8mm gallery across the front of the motor delivering oil to the motor. The system is low pressure due to roller big ends and mains, around 6-10psi cold, and around 1psi hot.

The modified system works thus: Oil is drawn from the sump via the oil pump, pumped up the 10mm gallery, past the right angle gallery to the original strainer (now blocked by the stainless screw in barb) out the stainless barb on the front of the side cover and on to the remote filter via a rubber hose linking the two. Clean oil exits the spin on filter via the push fit barb to the cooler via a rubber linking filter and cooler . Cool oil is then delivered to the round strainer housing cover, fills the void (left empty by the removal of the strainer) and into the 8mm gallery across the front of the engine delivering clean, cool oil to the engine.

The sump also contains a strainer through which oil to the pump is strained. Ideally, the spin on filter would be better placed here, however this involves fitting the spin on filter under the sump, leaving it prone to being struck by speed bumps, rocks and road debris. The standard sump filter is prone to being holed at one corner where there is a higher pressure load, so I fabricated a cover from light ally to protect the corner of the strainer.

[th62]

The TX was fitted with a twin cable throttle, one cable for each carb. Syncing the carbs was accomplished by adjusting the inline adjuster on the cable, a tedious, time consuming, nonsensical way of doing things. So, I designed and built a simpler system consisting of a cable splitter and two knurled adjusters, one fitted to the side of each carb.

I bought a single cable throttle on eBay and looked around for a splitter. All I could find was a plastic POS or a steel one with no means of securing it, so it would just flop around under the tank. Not to my liking, so I machined up a splitter from a lump of ally. I machined a step and drilled two holes for mounting the splitter to the upper engine mounts I made. Next, I bored a 14mm hole through and threaded it each end to a depth of 11mm with a 5/8"UNF thread, then machined up two end caps with a thread to match, knurling the knobs with a scissor knurled I made some years ago.

After this I turned up a brass slide, drilled three 1.5mm holes for cables and later used a slit saw to cut a slit to each hole for the three cables. When finished, I assembled the splitter, sealed the cable holes in the end caps and dunked it in an anodising bath I put together. I sealed the splitter prior to anodising as anodising leaves a thin veneer of oxidised ally over the surface which would have decreased the size of the bore.

To make syncing easier I turned up two 35mm long stainless, threaded adjusters, knurled the end, drilled through with 1.5mm hole, and bored out the cable end to 5.5mm to accommodate the cables. I then made up two ally brackets to screw them into and fitted them to the top of each carb.

Having synced the carbs with the standard inline cable adjusters before and now synced them using this new system, it is chalk and cheese: Much simpler and a lot quicker.

[th62]

I nutted out a simplified schematic for the TX last night and did a little work on it today. Rather than one harness, I decided on two, one for lights and one for ignition and charging. Five wires for the lights run up the left side of the backbone for lights, another three run up a harness on the right for ignition. I've included some earth cabling in the harness rather than just depending on earthing through the frame.

Once I've routed all the cables to their destinations, I'll zip tie them then wrap the harness removing the zips as I go. Having one harness for ignition and charging circuits and another for lighting simplifies fault faulting and cuts down on the number of colours needed in the harnesses.

I've ordered some stainless spokes, should be here this week. Can only get front spokes at the moment for some reason, seems to be a shortage on rears. As soon as they arrive I'll repolish the hub and rims and spoke it up.