Some work on a TX650.

th62

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The hub on the TX was in pretty poor shape, so I mounted it on the lathe, trued up the flanges, removed the casting bridges between the fins, trued them up then polished the hub and brake backing plate. The rims were badly scored from tyre levers and oxidisation, so I ground the edges of the rims down as much as I could then polished it.. Then I spun up some stainless spacers and aluminium dust cover. The brake anchor was a danged ugly thing, so I fabbed an ally one from 10mm ally, bending it to clear the tyre.

Brake actuating rod wasn't in the best of condition, so I binned that and made a new one from 6mm stainless rod and threaded it both ends. To connect the rod to the brake foot lever I made a funny looking stainless thingy, no idea what they are called, but certainly a lot better than the original piece of rubbish. At the other end of the rod I spun up an adjuster nut and pivot, also from stainless.
 

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That turned out very well
 
Front end rebuild. Forks needed a lot of work: Badly corroded and the previous owner must have only had a hammer and chisel in his tool box, the seal area was badly gouged, bits broken off and bent out of round. Not much I could do there, other than clean. Both legs had calliper mounts, but as the bike only has one disk, I ground off the mounts on the left leg, No need for the guard stay tabs as I've shortened the front guard, so I also removed the guard mount tabs then ground the leg smooth and polished both of them up. Whilst I had the innards out, I modified them a little by drilling two holes in each of the damper tubes, supposed to improve fork performance I've read. The stanchions had some deep rust spots up around the lower tree, so I removed the rust and applied some silver paint. As this area can be seen I bought some gaters to cover the area. Bottom tree was painted black, top tree was mirror polished, along with the brake line Junction. Whilst working on the front end I decided to do away with the headlight brackets and made my own from 3mm ally and machined up the risers.
The hub was mounted on the lathe and the flanges trued, there was a rather heavy, deep flange between the flanges, so I machined that down a bit so I get get a small mop in there, there polished it. I drilled some go fast holes in the disk, polished the edge, blasted the ally disk mount and fabricated an ally cover to replace the rusted steel cover that covered the left side disk mount holes. The lower tree was painted Black and the brake line distributor polished. I polished the top tree, machined up some risers and polished them also. Front rim was similar to the rear, badly damaged from tyre levers and a few accidents by the look. And finally I machined up some stainless spacers and pressed ally dust cover I also machined onto them.








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Some painting. Tank had one decent size ding and a few minor ones which I bogged up. Frame was blasted, welds cleaned up as best I could, unfortunately, the Japanese didn't know how to put frames together, nor could they weld when they built these bikes, so the frame is rough as guts. Pegs had the forging marks removed, guards were shortened, rear guad had a few dings which I panel beated and used just a smidgen of bog to smooth it out. Seat pan I put together some time ago. I float coated the final coat over 1200 wet and dry, but I haven't bothered polishing anything yet because I'll probably have to repaint further down the track. Bike already has a number of scratches and dings from resting in the workshop.
 

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The bike is looking great. A lot of effort on the the polishing. It's dirty work, but a very satisfying outcome. I have a 1980 650 Yam that I plan on turning into a dual sport configuration for back road use. Cheers, Mike
 
I never bothered to start the TX when I got it home, I put a compression gauge on it, the compression was down to around 65 in one, 80 in the other, so I never bothered trying to start it. Instead, I pulled the motor and stripped it down, this is what I found: the auto advance unit was a homemade, bodged up thing, cam chain was stretched, putting the timing out by around 60 degrees. Cam chain guide and adjuster were worn through, carbs were full of gunk, valves seats were pitted, there were a couple of missing pins behind the star on the shifter drum, so no gears, clutch basket was grooved, oil filters were totally gunked up, starter gear spring was loose, there were numerous leaks, the crankcase above the drive sprocket had been torn off, the bearing mount for the shifter drum was damaged, drive sprocket teeth were non existent and the retaining nut looked like Arny had got stuck into it with a sledge.

I had the barrel rebored two sizes over, had the valve seats reground, then sent off for some new parts: new pistons, rings, gudgeons, clips, cam chain guides, auto advance unit, carb kit, new second hand crankcases, gasket kit, seal kit, stainless allen kit, cam chain and probably a few other bits and pieces that I can’t remember now. I had the oil pipe re chromed along with points and auto advance cover. Manufactured a sump filter guard. The rocker shaft bungs are stainless bungs I found on ebay for a fraction of the price of OEMs.

While I was waiting for the parts to arrive, I blasted the cases, barrel, head, rocker cover, and carbs, cleaned them out afterwards with a pressure cleaner about a dozen times. Blew every orifice out at least two dozen times with compressed air and once satisfied they were clean and free of grit I painted the cases, barrel, head and rocker cover silver, polished the side covers, valve caps, dipstick, starter ends, cam chain adjuster housing and breather box, made new pins for the shifter drum, reworked the starter gear spring and started putting it back together in a stand I made for the job.

Once it was all back together, I didn’t fancy starting the motor up on the bench and watch it vibrate itself onto the floor, so I made another stand, with wheels and a rudimentary ignition system. I spun the motor over with my Milwaukee 18 volt drill for a few minutes to get the oil circulated, bolted on what was left of the two into one exhaust, filled the tank, switched it on and hit the starter button. I wasn’t expecting this, but as soon as I hit the starter button, the damn thing roared into life. And by crikey these things are shakers, with the motor going it started walking its way around the workshop, so I pulled out some rope and tied it to the bench grinder stand, then it just jumped up and down every time I gave it a handful. Of course, the carbs were way out of sync, so I put together a manometer and synced the carbs.

End of the engine story: Well, not quite, I thought the motor just looked so bland, so I pulled it apart again, stripped the silver paint off and painted the cases, head, barrel, rocker cover and carb bodies black, polished the carb caps and float bowls then put it back together again with new gaskets. And lo and behold, after priming it, it started straight away again. All good except for a small leak at the base of the barrel. I haven’t fixed that yet, instead concentrating on the frame and fittings.

So, that was the easy bit, the cycle parts have proved never ending, but that's alright, I enjoy my time in the workshop. Being a DIY kind of guy, I insist on doing everything myself, the only diversion from that was taking the frame out for blasting. So to come: New exhaust, seat pan with cowl, ally battery carrier, ally side panels, modified guards, ally tail light, ally brake anchor, stainless brake linkage, ally engine mounts, ally remote filter housing and mounting hardware, risers, cable splitter, ally coil mount, mods to the frame for side panel tabs and battery box mounting, modified fork legs, painting, and did I mention polishing, lots and lots of that: rims, hubs, forks, tree, brake collector, risers, side panels, tail light, battery box, battery retainer, brake ancho, brake backing plate, dust covers, wheel spacers, carbs, valve covers, breather box, cam chain adjuster, carbs, side covers, PMA mount, starter ends, dipstick, remote filter and cooler fittings. In between jobs it was back to the engine for a PMA mount, reg/rect mount, single point conversion, carb sync adjusters, plus a few more bits and pieces.

I can never ride the bike, it’s just a workshop project, so there is no end planned. I’m reaching the end of my time anyway, so after I’m gone the wife can sell it and maybe get some bucks for it, along with all my tools and machinery. I’d really love to take it all with me, but I’ve been told that’s simply not feasible!
 

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I decided to convert the electro magnet alternator to a PMA, but balked at the price of a kit. I could have searched for a second hand rotor, stator and banshee mount, but none of the wreckers around me had any, plus, who knows what you're getting with 40 year old second hand parts. I searched ebay and found a new rotor for a Banshee and a stator and reg/rect for an XV, all for $130Aust. I then bought a slab of ally for a few bucks and turned up a mount for it. A lot better than a dodgy, cut down Banshee mount. To time the new PMA I timed it with the original alternator, bringing the pointer on the rotor around to the timing mark, then removed it being careful not to disturb the timing. I then installed the new PMA, made up a pointer plate and afixed it to the side cover, installed the side cover then scribed lines on rotor and pointer plate. Prior to installing the stator on the mounting plate I polished it, this helps the lektrisity flow smoother.
 

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Single points conversion. I wanted to simplify the points system, but I do like mechanical things, so decided to convert the twin points to a single points system. There was a cam available for this conversion, but apparently they weren't very accurate, so I decided to make my own. First order of business was a backing plate which I made from some 3mm thick steel, shaped it on the lathe, filed cutouts for the minting screws and drilled and tapped the plate for points and lube felt.

Next I turned down some stock to 18mm, bored it 8mm, filed the ramps, then cut the keyway. Nope, timing was way off. Did it this way for a few attempts without luck. So, I decided to do it in reverse: Cut the keyway, mount the round stock on the advance rod, time the engine, gap the points, set the points at the midway position and mark where the heel of the points counted the round can and file the ramp. Success, I managed to get the timing for number one cylinder spot on with the correct dwell after only a few files. Next I rotated the cam 180degrees and did the same for the other ramp, success again. It's tiny bit out out, but nothing a quick touch up with a file won't fix. I'll also have to look at the points position on the backing plate, it's almost touching the bowl.

For this conversion, the two single outlet coils don't work, so I bought a twin outlet coil for CB750, made an ally bracket and polished it and mounted it to the original tab on the frame.
 

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