The TY lives again!

The mystery electrical problem goes on its summer hols

Weeks of head scratching have taken place while the TY gathers dust. Consultation with an expert in the field of jun- er, classic bikes and a bit of
diagnostic work revealed a distinct lack of spark.

A vote of the TY owners’ syndicate resulted in a resolution to get hold of a flywheel puller. JK Hirst supplied a new condenser, coil and HT lead (on the basis that they were cheap), which finally arrived after a couple weeks’ delay – neatly timed to coincide with Nick’s return from sunny Bloomfontein.

First on the list were the TY’s forks, never its strong point, which had developed a very distinct leak on the right-hand side after the first sessions of abuse around the farm. Draining the left hand fork produced a mucky black mixture. This seemed fairly unpleasant until the right fork was tapped, producing a copious rust-brown effluent.

After much struggle, the forks were disassembled, degreased, cleaned and covered (intentionally and unintentionally) in oils of many weights. We even managed to get them back together again, and in the right order. 15w fork oil and some new fork seals got some additional protection from tasteful black fork gaiters. At the very least, the oil should stay inside the gaiters and not run down into the front brake! We also made the saluotry discovery that our mudguard was not bent, but rather whichever previous owner put the front wheel back on last had put the spacers on incorrectly. So now the TY has a front wheel in line with the rest of the bike, putting an end to its budding career as a Daytona 1200 impersonator.

With the easy bit done, we settled down with our flywheel puller and an assortment of old TY workshop manuals to diagnose the mystery electrical problem. Which is to say, Nick sat down, while I stood and kicked. Initial analysis suggested that the condenser was toast, making the replacement an inspired purchase. After struggles with solder and knives, however, no improvement was evident at the plug. The coil and lead were changed, again producing no improvement. In desperation, the magneto’s coils were removed, cleaned, inspected and replaced. A desultory kick was attempted, eliciting (to our surprise) as healthy a spark as 6v electrics were ever likely to produce. After the usual ceremonial dousing of the crankcase with premix and swearing, the TY fired first kick and was soon thrumming away happily to itself.

A short test ride and some mild leaping from highish things showed substantially improved damping from the forks. Whatever magic had been worked by Nick on the electrics produced substantially improved tickover and bottom-end response, and turns became tighter and wheelies easier than ever. We’re both looking forward to actually getting the TY in a trial!

Bits and pieces

Bits and pieces

Another weekend and some more tinkering with the TY as Nick is lying on a South African beach, fanned by nubile maidens and eating grapes. But this time, in bright sunshine rather than freezing rain.

E-bay supplier trail and trials furnished me with a set of replacement bolts and brackets for the rear shocks, along with a new kickstart rubber and a spare shift lever.

I had been planning to keep the shifter as a spare, but it looked like such a surprisingly solid piece of kit that I thought I’d put it on. Plus, I’ve heard that you have to keep an eye on the shifter and kickstarter, as they can come loose and wreck the splines on their respective output shafts. The amount of dirt and old grease visible on the shift lever made a good clean seem like a doubly good idea.

With the splines cleaned up and new lever torqued and locktite’d, it was on to the shocks. The old allen-head bolts had been looking nasty and rounded-off, but thankfully they’d not been highly torqued. For some reason (presumably chain clearance), the drive side shock had two washers behind on each shock mount. The mounts themselves were coated with a rust-coloured solution of what was probably 20 year old grease – glad I bothered, then. With shock mounts cleaned up and heavily greased, the freshly scrubbed shocks were ready for remounting.

While I was at it, I decided to replace the plug, the old one having been in situ for at least two years. Checking the gap revealed it to be rather larger than spec’d in the manual (0.5-0.6). It looks like whoever changed it last didn’t have a manual and didn’t bother re-gapping the plug. The new plug seems to have made a noticeable difference, with much crisper throttle response and better wheelies. Well, these things are important!

Next week should see Nick back in action and a fresh pair of “classic” black grips delivered, ready to replace the tired and decidely non-matching blue Scott items. While we’re messing with the front end, it’ll be a good opportunity to check the mangled fork-top nuts still come out and then drain and refill the fork oil. As a Yamaha owner of old, I am familiar with chocolate fork seals and questionable finishing. So that will also be a good opportunity to fit the tastefully matching pair of black fork gaiters currently bouncing around my spare room.

TY: too keen ?

The joys of Old Bikes

Although startingly lustily at the first kick (unlike my Duke…), an hour or two’s ride around the farm showed that the TY was demonstrating an almost Velocette Thruxton-like unwillingness to idle. Rather more seriously, after warming up, fuel began to pour from one of the carb vent hoses and collect in the inside of the bashplate.

On the up side, this means the TY has probably the cleanest bashplate of any twinshock in Britain. On the down side, it’s patently not a sustainable lifestyle for any bike. Consultations over, and with the arrival of a CD containing the workshop manual anticipated, plans were in place for removal of the carb and a good seeing-to. For the carb, that is.

JK Hirst supplied a new valve float needle and holder (for elimination of the obvious suspect), float bowl gasket, main jet and slide spring (just for kicks), as well as a new air filter. If there’s one thing I hate more than oiling a new foam filter, it’s cleaning a used one. And knowing the effect I usually have on fork sliders, a set of tasteful black gaiters was also obtained.

Reviewing the recommended service intervals had me falling off my chair. I had thought you only got a chart like that with a new RS125! As a practising four-stroke owner, I contemplated the likelihood of inspecting and cleaning the cylinder bore, piston and rings after every 20 hours and, simultaneously, the likely number of hours before the first seizure (the piston’s and Nick’s, in that order). I was amazed to see that there’s an integrated chain oiler in the swingarm. Hold on, why doesn’t every bike have one of these? As someone had plugged up the filler, maybe there’s an answer to that.

This weekend, with tools arranged tastefully in the dirt, the TY hauled onto a handy stand (try that with a Duke!) and Nick tucked up in his bed with “Blanky”, it was time to see how many of the Phillips-head screws (!) holding the TY together had been touched since 1976. The shocking state of the fork top bolts sent mixed messages.

Falling at the first hurdle, I completely failed to remove the seat. In my defence, this is not anywhere in the manual. After removing the side panel and loosening the clamp under the front of the seat, vigourous peering failed completely to reveal what the fudge was retaining the rest of the seat unit. The swearing, creaking of plastics and carefully moderated straining familiar to amateur bike mechanics ensued, until inspiration hit. Which is to say, I gave up completely and resolved to crawl meekly to a trials forum. Or Malc.

With some trepidation, I attacked the carb instead. To my amazement, the screws holding the carb rubber clamps slackened off without complaint, together with the float bowl screws. Obviously the TY was made of sterner stuff than my TRX, whose float bowls are held on with patented ’90s Yamaha “Shitmetal” (TM)(R). Having unhooked the slide and its collection of dirt, the float bowl gasket’s resistance was overcome with a sharp tap from a drift.

Copious amounts of degreaser and carb cleaner followed. All the brass showed evidence that the bike had been left for at least the known couple of years in a shed, with a dull brown layer of varnish coating everything and having pooled on one side of the float bowl cover. More scouring! With the help of the settings in the manual, mixture screw and idle speed adjuster were cleaned and re-set. The mixture screw, which was supposed to be 1 3/4 turns from fully closed, had been set, well, let’s just say many turns out.

After some purple-faced moments swearing at the slide spring (cured by adjusting the throttle cable all the way out) and more swearing at the carb rubbers (which would only seat properly on one or the other end of the carb, but not both), an inspection of the plug was made. This revealed quite a bit of carbon buildup, and after a quick go with a wire brush, a mental note to just buy a new one. It didn’t seem that any torque had been applied to the plug at all, which seemed incorrect. As I didn’t have a 20mm spanner and had resorted to a plumber’s adjustable wotsit, I wasn’t really in a position to be judgemental.

With some fresh petrol and fingers crossed, it was time to see how badly I’d buggered it. Well, after belatedly reattaching the fuel feed hose and cleaning a lot of petrol off the cases, anyway.

After a little time for the fuel to get to the float bowl and a couple of preparatory kicks, it fired up and proceeded to immediately idle at about 5,000 rpm. This was progress, as last Sunday I spent about 30 minutes trying to get it to stay running. The idle speed screw appearing to do precisely bugger all, so in desperation I backed the mixture screw out a couple of turns. Result – we were back to a fast idle. This explained why the mixture screw had been wandering in the wilderness of many turns out. A quick trundle down the drive revealed a happier sounding two stroke (less popping, more whizzing) with fuelling more like Malc’s 350 jumbo – hanging onto its revs on a closed throttle. This may not actually be “spec”, but at least it starts easily.

The lesson I have learned after all of this is that I should have just ordered a spanking new carb and throttle for £39.99 rather than spend £25 on parts and freezing in a barn for a couple of hours. But now at least I have a joyful, relaxed 4 hours of trialling before the piston welds itself to the bore!

In our next episode – Nick struggles from his bed and fixes the horn so we can get an MOT. Um, well, maybe.

Nick and Ian’s Boringly Predictable TY250

After a few goes on the furious big-bore TL, Ian and Nick have, with tedious predictability, bought themselves a 1976 TY 250 twinshock in mostly good order.

Unlike most of Malcolm’s bikes, it has started its new life in one piece and with apparently entirely complete cycle parts (ok, it might have a set of very subdued pattern levers), missing only the autolube and the original decal for the mid-pipe leg guard. Also unlike most twinshocks, both brakes work and are capable of actually retarding the bike above a speed of 2mph. This may or may not have anything to do with its last home, which involved a garage full of spotless, concours condition BSA A65s and their restorer. He was clearly a qualified ninja mechanic, as evidenced by acres of gleaming chrome and the fact that all the oil was inside the bikes, rather than distributed evenly across their crankcases.

So, yet another TY. “Where is the challenge?”, I (we) hear you cry. For us, as near-virgin trials enthusiasts, the challenge is avoiding effeminate squeals or wobbling into a tree. Tales of woe, misadventure and ruined shrubbery are sure to follow…and we may even do some trials.