I bought this 74 TX650 a few years ago as a long term project, just something to keep me occupied and keep me moving. I have chronic, untreatable RA so my body hasn't fared too well so far: fused fingers, toe joint replacement surgery, hip replacement surgery, ulna nerve transposition and so on, so everything takes a long time to do. The bike was a wreck when I bought it badly oxidised, pitted and rusted, missing parts, crankcase wrecked by an errant chain, no compression to speak of. Coming to the end now. All handbuilt in my workshop, fabrication, welding, painting, machining, electrical, metal polishing, anodising, spanner work, spoking and so on: PMA conversion, carb conversion, single points conversion, manifolds, exhaust, tail light, headlight brackets, risers, side panels, battery carrier, seat pan, and lots more. It came with a few spare parts carbs, spoked wheels, indicators and so on. Here's where I'm up to.
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!
The alternators on the XS650 are a well known weak spot as they they don't generate enough power, Zip at idle. Frequent stop start riding usually resulting in a flat battery. The alternator has an electro magnet spinning inside a stator. Brushes are mounted on the stator cover which supply power for the electro magnet. Quite a silly setup in my opinion, the brushes don't necessarily present problems, just the low output does. I put the multimeter probes over the system and found everything reading within specs, but still I didn't like this system, so bought a permanent magnet rotor, an internal stator and a combined regulator rectifier off ebay for an all up cost of around $130. Kits are available with exactly the same parts, but sell for $500-$600 and they come with an adapter to fit the stator to the engine cases. Damned if I was going to pay that amount! The parts arrived, so I took some measurements and spun up a mount for the stator from two bits of aluminium and also stepped a 6mm woodruff key down to 5mm to fit the XS keyway. When I fitted the key to the shaft I found the diameter of the key was larger than the keyway diameter on the crankshaft, no good! I then turned up a piece of stock to the required diameter, cut it in half and stepped it - perfect fit. The stator mount was made in two parts as I didn't have a piece of aluminium of the right thickness, around 45mm from memory. The magnetic field of the rotor dictates the positioning of the stator, so I mounted the stator inside the rotor, fitted it to the crankshaft, took some measurements and from them spun up the mount. Everything fitted up great, but, the original rotor had marks on it for timing, as the new rotor was for a Banshee and the stator for an XV, there weren't any marks. So I fitted the original alternator, timed the engine, then carefully removed the assembly and replaced it with the new alternator assembly, made up a pointer plate which fits in the side panel and scribed lines on pointer plate and rotor. When I finally got around to starting it to test my mods: Alternator, single points, cable splitter, wiring, it started up straight away, the timing was spot on and the single points timing was also spot on. Alternator output was 14.4volts right from idle, as opposed to the original alternators output at idle - zip! This is the single, most popular mod for XS650s, which just goes to show how much love there is for the stock alternator. A lot buy second hand rotors and stators and bodge up a Banshee mount to fit the XS, saves $. Most however, say hang the expense and fork out the big bucks for a kit.
Here's a couple of risers I made. Couldn't find any I liked so I machined these up from a lump of 25mm aluminium.
Single points conversion. I've converted the twin points system to a single points system. To do this I manufactured a single points backing plate with a lube bushing. Drilled the points bucket at top to route the cable to the coil under the tank. I bought a dual outlet coil, made a bracket for it and mounted it to the original coil mounting frame tab. The cam proved a little problematic: I turned down a bit of stock to 18mm, filed two ramps on it, then cut the keyway, no luck timing was was way off. i made a few of these but couldn't get the keyway in the right place. so, I decided to do it in reverse, cut the keyway first, mount the cam, turn the engine over to the firing mark, mark the points heel position on the cam and file away. Then turn the engine over 180degrees and do the same for the second ramp. Super easy this way, I got the timing almost spot on for both cylinders with the same dwell as the original cam. These cams were available from a number of outlets, but apparently they weren't very accurate, so most outlets no longer carry them in stock. The first two pictures show the timing for for numbers one and two cylinders, using an LED timing light I put together.
The TX came with an extra set of spoked wheels, they were pretty bad shape, spokes were rusted, rims were badly scored by tyre levers and oxidised and pitted, same with the hubs. I mounted the rear hub on the lathe, turned down the casting bridges between fins, straightened the fins and trued the flanges then polished it. The front hub had two huge bridges between the flanges making it impossible to polish, so I turned a little off the bridges, trued the flanges and polished the hub. The rims were in a shocking state, badly oxidised and pitted with numerous lever marks. I ground the rim edges to remove as much of the damage as I could, then ground the rest of the rims with nylon fibre wheels to remove as much pitting as I could, then polished them. Unfortunately, I couldn't fix all the damage or remove all of the pitting, but they came up pretty good, you have to look pretty close to see what left of the dame and pitting. I then turned up some stainless spacers to replace the well worn originals and pressed some aluminium dust covers I turned up over the top of the spacers. The front rim had ah rusted steel cover covering the holes on the left side of the hub for fitment of a second disk. I fabricated an ally cover in it's place. All fasteners were replaced with stainless fasteners and I laced both wheels with stainless spokes. They came up pretty good I think.
I've designed and put together a couple of much simplified harness' one for lights, the other for ignition, minus stuff I don't require, neutral light and so on. But still the spaghetti bucket lived up to it's name. I dislike untidy with a vengeance so made a bracket that sits inside the spaghetti bucket to try and keep things neat and make it easier to find and connect the wires. Two grommets sit in the middle for routing earth wires through to earth connections and a couple of linked, Delrin, insulated terminal bridges sit either side of them for power connections. Mostly connected up, but still have to connect the headlight cables and speedo light cables, not sure about adding idiot lights, more procrastination needed there me thinks! The cables emanating from the switchgear are very, very light gauge, not sure if they'll handle the current, even though all lights are LEDs, so I may have to either solder in heavier gauge cables or change the switchgear.
Finished off the front wiring and spaghetti bucket. Still looks a little untidy, but neater than most I think. I even mounted the lens on a couple of wire safety straps to stop it pulling on the harness. I had, to buy these double female bullet connectors from China, couldn't find anyone in OZ who stocks them. Trying to find sub 6mm eye terminals was a job, same with 3mm blade terminals, they stock female blades but not males. And they complain that everyone is turning to online shopping - no bloody wonder. Got to attack the back end now, mount the indicators and plug them and the tail light into the lighting harness.
The indicators I bought don't have a long enough threaded section to go through the guard bracket, so I made these extension brackets to mount the indicators on. The V shaped cut out at the rear of the brackets fits around the frame tab protrusion, thus stopping the brackets from moving.
