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Thread: 74 tx650

  1. #1

    Default 74 tx650

    I bought this 74 TX650 about 12 months ago as a non goer. It was missing a few bits and looked like it had been parked in the ocean, aluminium was badly pitted and oxidised and steel fittings completely rusted out. At some stage the chain must have come off, a piece was ripped off the top of the top crankcase and the shifter drum bearing housing ground off.

    I've done a lot of work on it over the 12months, bought second hand cases, new cam chain and guides, rebore, new pistons , rings and gudgeons, gaskets, seals, stainless fasteners, auto advance unit, plus a heap more parts. Blasted and painted the cases and stuck the motor back together.

    I've made a few mods and made a heap of custom parts for it: PMA conversion, single points conversion, ported, remote oil filter and cooler, exhaust pipes and brackets, headlight brackets. Some of the parts I've machined up: Handlebar risers, cable splitter, PMA mounting plate, ally battery box, hand beaten side covers, single seat with cowl, tail light, positive stop nuts, oil filter housing, ally engine mounts and so on.

    I do everything myself: Paint, electrical, mechanical, machining, metal polishing, welding, tin work, upholstery, anodising and so on.

    This is a project to keep me busy till the end of life, I can never ride it as I have chronic psoriatic arthritis, so fingers have been fused, joints replaced and so on, making for a few limitations and slow progress. With these hands everything takes ten times longer. Luckily, my wife is a good sport, she uses the hammer for me as I can't bash stuff anymore. She also sweeps the floor, cleans my lathe and mill, but shush, she doesn't know I can still do that.

    Some pics of my project as bought and where I'm up to.
    Attached Thumbnails Attached Thumbnails as bought left.jpg   damaged crankcase.jpg   damaged shifter drum mount.jpg   oxidismed right cover.jpg   206541852_4436422206403213_6352052716125558292_n.jpg  

  2. #2


    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 canít 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 didnít 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 wasnít 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 havenít 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, itís just a workshop project, so there is no end planned. Iím reaching the end of my time anyway, so after Iím gone the wife can sell it and maybe get some bucks for it, along with all my tools and machinery. Iíd really love to take it all with me, but Iíve been told thatís simply not feasible!
    Attached Thumbnails Attached Thumbnails 150300-e73806504f700bafd4a0f5e85eed2586.jpg   150295-a18f370eb09f40fdef742224ad22a470.jpg   150294-7897e56f275288b3ae336ca9933b47c5.jpg   150293-7395a10d03f6a5813527f65c964a24de.jpg   150292-f9a45f131eb258f1f342c92f1b8d3403.jpg  

  3. #3
    Senior Member

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    Mar 2012


    Non goer. That's awesome

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