Thread: New bike - TX650

Well, finally got around to tapping 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.
Remote filter and cooler and bracketry are all done, just waiting for the 120degree AN6 fittings to arrive so I can connect the hoses. I'll post pictures as soon as the connections are done.

I put together an anodising bath the other day and did some experimenting. Bought some acid, diluted it, made a couple of aluminium cathodes and hooke everything up to a 10amp power supply (projecta battery charger). Results were good, although I'll have to do some more experimenting with electro polishing, the anodising process totall kills the shine on aluminium.

I'll use the annodising for ally parts that can't be polished regularly due to positioning on the bike. I have an ammeter and some titanium wire coming, so I can upgrade my rudimentry annodising bath.

First piece in the bath was a polished aluminium bracket, as you can see the finish is nice enough, but rather dull. Second piece was polished on one end, the other had a brush finish. Polished aluminium definitely comes out the best. Second pics are before and after shots.

The TX650 came with a silly twin cable hand throttle, one cable for each carb. I bought a single cable throttle and looked around for a two into one junction box. Only one I could find were made of plastic or steel with no means on mounting them, so it just flops around under the tank with the cables.

Didn’t like that idea, so I made one from a small slab of ally. I bored a 14mm hole through the slab and ran a 5/8” UNF thread through each end on the lathe to a depth of 11mm. Next I milled a step and drilled two 6mm holes in the step for mounting it to the upper engine mounts.
The two end caps are also aluminium turned up from some round stock. One has a one cable inlet, the other takes two cables. I ran a 5/8” UNF thread on them and then ran my scissor knurler over them. Both caps are fitted with O rings as the body will be filled with grease for lubrication. Only the second time I’ve used this knurler since I made it about five years ago. It works well.

The slide I made from brass, 14mm round, for a snug, sliding fit inside the main body, and 25mm long. Through this I drilled three 1.5mm holes, then countersunk them with a 3mm bit for the cable nipples. I still have to cut three slots with a slit saw in the slide, so the. Cables can be fitted.

Not sure of the finish, but since it’ll be unseen, under the tank, I’ll probably stick it in my anodising bath.

The fittings I ordered to complete the oil filter/cooler job arrived today, so I finally connected everything. Looks ok, but a bit of a jumble of hoses. Turned into a rather big job this. Had to make some new engine mounts with room for the filter housing. Machined up the filter housing and threaded stainless parts for plumbing. Machined up a cover to replace the original filter housing cover. Fabricated a bracket to bolt to the engine mounts for the cooler. Drilled and tapped the the engine side cover. Then polished everything - Big job. These AN fittings are very expensive, $50 for two. I ordered them on Aliexpress first for half that, but the seller cancelled the order for some reason and now I'm having trouble getting a dam refund. Some of the parts I had to machine up

Turned up a couple of these today, they're cable adjusters for my TX650 build. 8mm stainless rod, turned down to 6.36mm for the threaded end. I cheated a little bit on the thread: Ran a 1/4" UNF button die for about 15mm on the lathe to get the thread straight, then transferred the piece to the vice to finish off the 40mm long thread. Knurled the thumb pieced with my homemade scissor knurler then drilled through with a 3mm bit, followed by a 5.5mm bit for a depth of 12mm to take a cable. Still have to make a bracket to bolt to each carb, but this'll allow very fine adjusting when syncing the carbs. These will thread over the inner cable before the nipple is molded in place.

Exhaust pipes. I mocked up a pipe for the right side, welding together some exhaust pipe at the appropriate angles with the right amount of twist then took it to an exhaust centre and asked them to mandrel bend two bends from 42mm pipe to match the angles, so I could weld them together later. The exhaust guy assured me he could bend the entire pipe with the correct twist, then reverse it for the left side, so naturally I jumped at the chance to avoid welding the two bends together. Roll on five weeks, yep that's right, it took him five weeks, and I picked up the pipes and took them home. Well, what a balls up, the only thing that was correct was the twist. So, I cut both pipes around half way between the two bends, removed a 25 mm section and welded the two bends together. Problem! The bottom bend was way out, leaving the exhaust bending down toward the ground. To fix, I made a V cut in the pipe a few inches after the bend, bent the tail section up and welded the two pieces together. Repeating the process for the other side. Now, if you think exhaust pipe is round, it ain't! So twisting the pipes and butting them together leaves a few steps. So, I hammered them a little so they'd match up, welded them together and ground them smooth, then painted them with exhaust black pint.
I mounted some 10mm thick ally in the four jaw, turned up the 42 mm hole, then marked the position of the 10mm exhaust stud holes drilled them through, shaped the clamps and polished them. For the lower mount, I bent up some 3mm steel plate in a half circle with short returns either side, shaped another 3 mm piece of steel to affix to the frame and welded it to the half circle clamp, then painted it exhaust black paint. Next I bent some 3mm ally plate in a half circle with returns each end, stuck it together with the steel half circle and drilled through four holes for stainless Allen heads, and polished the ally half clamps. The pipes have a very slight upwards sweep.​​

Pushed the starter button this afternoon and the TX roared into life, very loudly with those pipes. So, the single points cam works beautifully. PMA conversion works well as does the dual output coil, cable splitter, remote filter, cooler and ignition wiring. It's running a little lean at the moment due to the pods and exhaust, so I'll have to rejet before syncing. Very happy chappy. https://www.youtube.com/watch?v=nJ-BRcUOwKk

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.

Here's a video. Still needs syncing but starts and goes well. https://www.youtube.com/watch?v=nJ-BRcUOwKk

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.

Front spokes arrived from Geoff's this afternoon, so I laced up the wheel. The spokes for the rear wheel are coming from Heiden Tuning, so they probably won't be here for a while. Much better looking than the mags I think.

Unfortunately, there is more thread on the new spokes than on the stock spokes. After I laced up the shell and trued it I found there was 3mm of thread showing on every single spoke between nipple and hub, it looks ugly and unprofessional, but nothing I can do about it.

When I advised the seller, he told me it was normal and I didn't know what I was doing and then proceeded to send a number of abusive texts and emails and told he won't deal with me anymore. As if I would!

You can see in the pictures the new spokes have a longer thread than the stock ones.. The stock ones are the dull grey ones.

The BS38 carbs are gone. These are SU type carbs, comprising a butterfly and a slide and needle operated by vacuum, a totally ridiculous design in my view. Anyway, the diaphragms being 46 years old, started developing tiny pinholes. I plugged a few with Sikaflex, but they just kept coming. Yo can't buy the diaphragms by themselves in OZ, you have to buy the diaphragm and slide at $300, damned if I was going to pay that to fix a couple of carbs I think are rubbish.

So I sent off for a couple of Mikuni VM34s. These are normal slide carburettors, simple and they work well, giving a slight performance boost. These come with cables and, manifolds and rubbers for $600, darned expensive, but heaps better than the BS38s. Carbs arrived and I bolted them on only to find the cable on top sits right where the fuel tap is. I contacted the seller and apparently, due to Yamaha's manufacturing processes back in the day, no two XS650s are the same, so the cables interfere with the fuel taps on some but not others. I'm just lucky, story of my life.

I did some checking and found that if the VMs are mounted in the original manifolds, the cables miss the fuel tap, trouble is the VM spigots are 40mm, where as the manifolds are for 48mm spigots. So I had three options: tilt the carb over at quite an angle to miss the tap, Fit the VM spigots with a 48mm sleeve or machine up some longer manifolds to place the carbs behind the taps. Options one and two, went out the window, option one for obvious reasons, option two because I'd have to turn the spigot down a little to make it smooth enough to take a sleeve. That's not something I fancied doing, so, I set about machining up a couple of longer manifolds.

The mounting flanges measures 90mm across, so I'd need a 90mm round piece of aluminium stock to turn down to 40mm for the spigot and bore through 40mm, that's a lot of wasted aluminium. So, better idea: turn up a couple of 70mm long 40mm spigots with a 34mm bore, machine a couple of 90mm wide flanges and press the spigot into place.

I made one and it came up excellent, so then I made another identical one, well, nearly identical, the second one came out 0.20mm longer, but I can live with that. Once finished I polished them, fitted them and fitted the carbs - success, The cable sits 10mm behind the tap and gives good access to the adjusting screw for syncing. Problem! The outlet spigot from the tap sits right up against the carb cable. Easily fixed, swap the taps from right to left and left to right and the outlet spigots now face forward, away from the carbs.

Next problem: the carbs are normally supported at the rear by the airbox, but as this custom doesn't utilise an airbox, the carbs would in all probability stretch the rubber boots and the carbs would fall off. So, now I needed some sort of a support at the rear. So, I made up two U shaped brackets to fit over the slot at the back of the carbs, fitted them with rubber grommets and positive stop T nuts, then I made a larger flat bracket which bolts to the rubber mounted battery carrier and mounted the U shaped brackets to that, then anodised them.

Worked a treat and not too obtrusive or ugly. Next step, shorten the cables, I machined up a 6mm nipple and soldered that in place, then routed some fuel hose from tap to carsb. Another problem; The taps have a 6mm spigot, whereas the carbs have an 8mm spigot. Back onto the lathe to turn up a brass adapter.

All done, so I wheeled it outside, started it up and tuned it. Runs like a beauty now. But geez, what a lot of work!

Some pics.

Here's the rear wheel all spoked up, a lot better than the front as there is no thread showing. I thought I'd add a picture of my lacing helper, very technologically advanced piece of kit this. Took days to put it together. And a pic of the bike with the wheels.

I made this this afternoon, total waste of time because this senile old fool made the slot too small. On the plus side, at least I know it's easily done and should look Ok in chunky, polished aluminium. Tomorrow I'll pay attention to what I'm doing and make one with the right size slot.