August 2023

Allan bought this T160 by wire from Baxter Cycles in 2012. It arrived just prior to xmas, and he brought it around to show me after collecting it from Lyttelton. It was in the back of a Hiace van, and the plan was to squeeze the grey frame Rocket 3 in with it for the trip to Blenheim, but it wouldn't fit, so the Rocket stayed.

The following day we had a big quake, the Rocket fell over in the shed and broke a number of things. Bugger.

Despite much encouragement, the T160 sat for some years, during which the oil tank was removed for repairs, the exhausts came off, then it was relegated to the back shed and progress stopped.

During one of my recent forays into the back shed I liberated a number of bikes, and this was one. I found all the parts that had been stashed in various boxes, and it came down to my shed a few weeks ago to take its place in the queue.

I soon had it looking much worse.

The battery tray needed to come out as it was quite badly corroded, plus the wiring was looking terminally bewildered, the rear brake was seized solid, blah blah blah. The rear wheel would be coming out for a tyre, so I decided to pluck all the rear mudguard assembly out so as to make everything accessible for a major tidy up.

This led to removal of the seized carb assembly as well as anything else that dared to get in my way.

Looking ahead I could see that the US bars would have to go. They tend to make the rider into something resembling a sail...

So my attention was diverted to the front of the bike. It has been my usual practice to work my way from the front to the back as far as cycle parts go, and the front end had a number of observable problems.

A peek inside the headlight revealed it to have the north american headlight relay still fitted. This is a solid state thingie whose purpose is to make the headlight permanently on when the bike is in use. I suspect that this is what led to everyone fitting high power alternators, as the headlight drained off too much of the meagre charging current to allow the electric start to establish a good reputation.

My T160 was an Australian export and had the home market wiring. As I don't ride with my headlight on, I have never found the original electrics to be wanting. Of more recent times I have been fitting LED parklight lamps in the headlight, and they double as a daytime riding light of the annoying variety for oncoming traffic.

Headlight wiring mostly unmolested.

Front brake was also in trouble, as all the flexible hoses are shot. While the brake did actually function, the master cylinder was looking well past its best-by date, so my planned approach would be to fit a new front master cylinder and relegate a refurbed old front unit to the rear where it is out of sight.

With the bars removed it was easy to remove the headlight and give it a ten year overdue polish. The indicators needed repairing, and the headlight brackets required a bit of panel-beating, as the bike had obviously been dropped on the right side at some time.

I could not resist fitting a pair of used bars to see how they would feel. I also replaced some rubbers in the bar clamps, so they no longer wobbled about as the originals had. This led to two discoveries. There was something amiss with the steering head bearings, and there was a mysterious 'click' from the lower front forks when turning the bars left and right. It turned out to be some massive play in the front wheel bearings, so they are naff.

I backed off the tension on the steering head, but it still feels ropey.

Tank appears to have had some recent paint before leaving the US, though they never got to the pinstriping.

The front forks had been set protruding above the top triple clamp so needed lowering, the fok oil needed changing, the brakes needed fully rebuilding and the front wheel had to come out for bearings and tyre, so that got the front end stripped.

Everything behaved itself and as the fork seals were not leaking I left them alone. I did replace the O rings on the damper valves.

The wheel bearings eventually complied, as did the new TT100 GP, but it put up a hell of a fight. I had to inflate to 60psi about 6 times over 24 hours to get the last section of the bead to pop out.

While messing with the forks I got the impression that the steering head bearings were still too tight, even though I had already backed them off some. I undid them further and was rewarded with a happy steering action at last. Must have been interesting dropping this thing into corners..!

The 'bars I had trial fitted were what I wanted, but they were too narrow for the brake cylinder to get along with the speedo, so I got a set of stock T160 'bars instead and fitted them up. With the new brake hoses and some paint on the housing, it all has started to look a bit fresher.

As I had the rear wheel bearings on hand I decided to pluck the wheel for bearings and tyre replacement. This led to much cleaning of frame and swingarm, plus some relieving of the crushed alloy of the speedo drive, where they always get forced inwards and grip the rear axle very tightly, making axle removal a bitch.

All of that work was completed happily enough, and I chose to refit the inner tube as it looked unscathed. The following day I found the tyre to have lost pressure, and rued my decision about the tube, but thought I should check the valve in desperate hope it might be the culprit. Now I looked at the valve in a suspicious light it was indeed shifty, as its return spring was way compressed and relying solely on air pressure to seat. I fitted one I found, a short type with no spring and a much more youthful appearance. To my delight the tyre has remained inflated since.

Suitably enthused I began the long cleanup of the mudguard assemblies, tail light assembly which required the "cable tie mod" to extend lamp life, then redid all the tailight and indicator wiring so that wires were not stretched tight across the mudguard where the seat could pinch them.

Everything came up nice, with a fair bit of elbow on the polishing, and pointed me in the direction of completing the wiring overhaul as the next step. The battery tray would be necessary as it is wiring central, and the Rita needed to be somewhat more carefully mounted beneath it before the wiring could be made to suit. I decided to remove the starter assembly now, as it would make the wiring more accessible.

The wiring takes ages to organise, as there is limited space and there is always damage to repair. The battery earth wire insulation was melted, a sure sign that someone left the heavy current starter cable off at some time, and the starter tried to draw massive current through the small wires intended to only handle accessories.

Part way through the wiring I decided to refit the starter to dictate some of the wiring positioning, so the starter got some maintenance and a good overall clean before rejoining the ship. I shall remove and clean the end cover later, as it is easier to manage when the starter is held in place. The chrome cover was put in place to check some panel beating I used to straighten its butchered front edge.

With the wiring on the right side complete I moved to the left to rehash the Rita setup. I found that I could re-use all the original points/condenser/coil wiring in a different way to get power to the coils and back, plus to the original ballast resistor which is used in series with the third coil as one of two 12 volt circuits the Rita powers.

To add to the mix I mounted the usual relay behind the flasher unit, as this helps to keep voltage to the ignition unit as high as possible to assist good starting when using the electric foot.

A bit of necessary re-shuffling in the shed then got the two T160s together so I could use my bike as a template for where everything really needed to be.

It all came good in the end, and I was confident enough to put a battery in place to check all the electrics. As usual the old Lucas flasher unit has completely run out of flashes so some form of new one will be fitted. The only other thing that didn't work was the neutral light, and it seems that the switch is either naff or badly adjusted. I will need to drain the gearbox oil in order to find which of these it is. There is another reason why I am going to drop the switch out - there is a tiny plunger fitted above the switch in its housing, and people often lose it when working in there as it can just drop out if you are unprepared. As I can only select first gear, the outer cover may have to come off the gearbox as well, so I need to decide what order I shall do things gearbox related.

Looking a million percent better though..

In other news, a badly bent footpeg got straightened by a handy mate, and the oil tank has been panelbeaten and painted, but one of the mounting lugs is proving to be reluctant to stay attached to the tank, so it is getting some more welding practice. A new bezel for the sidecover arrived, so that got fitted along with a new 'Trident' decal. A new swingarm bolt arrived to replace a butchered metric bolt someone had stuffed into place. Fortunately the original thread inside the cast frame housing cleaned up ok. The engine plate will need paint to hide signs of the butchery, but I will wait to see if I need to remove the inner primary case at the same time.

I checked the primary chain tension today and it was way over tight, so I am thinking I should pop the outer primary off for a good look at the state of things in there. I also found that the rear chain is pawked, with several tight spots and enough wear to have warranted its retirement anyway.


One move leads to another..

There was another reason I needed to pull the primary cover off, only first gear is selectable and this could be due to the cross shaft 'feet' being incorrectly engaged in the primary cover, so two reasons meant it was coming off now.

A wonderful sight to behold - it all looks as-new in there, and the cross shaft was timed properly, so problem is in the gearbox. My prime suspect would be the 'up' plunger that engages with the quadrant being either stuck, or having a broken spring.

It would be prudent to pluck the inner case and check the clutch while the outer is off, but several factors made me decide not to. The clutch adjusts and operates well at rest, there are no signs of any oil from beneath the clutch housing, the pullrod bearing feels free and smooth, the primary chain has been off at some stage, so perhaps it has already had a new clutch plate fitted, and if I disturb it I will have to replace all the bearings, seals and gaskets, simply because I was in there. We will see how it performs under fire.

All bikes, and certainly triples, have a few operations which are kind of annoying. On the T160 the bottom mount for the oil tank demands maximum dexterity to refit, but also removing the rear brake pedal which has a quite ferocious return spring, and in order for me to remove the gearbox outer cover to continue the gear selecting mystery, the brake pedal sure had to come off. I figured I would cheat, and instead remove the engine mount plate through which the brake pedal was mounted, leaving pedal and spring in place. It only takes 10 minutes as a rule, and it would be easier with the footpeg missing, which needs painting after being straightened. Sure enough, it was off in a trice.

As I now cleaned the previously hidden grubby bits I realised something that had not occurred to me before. Looking at where the oil tank mount bracket bolts to the cast part of the frame that the swingarm bolts through the engine plate I had just removed, I could see that the oil tank mount would be an absolute cinch in this state.

I guess I know in what order it will be going back together then.

Today I only managed to drain the gearbox oil and begin preparation for removing the gearbox outer cover, where hopefully I will find the answer to the missing gear mystery.

Play resumed and the gearbox outer cover came off, with some very thin oil emanating from within it. Within seconds it was apparent that the quadrant was indeed unable to move in any other mode than between first and neutral. I decided to remove the neutral light switch first, as it was not working and seemed to have been leaking a slight amount in the past.

The switch was absolutely seized solid, and now the quadrant was free. I fitted the gearlever on the primary and every gear was available and selected nicely. While I was hoping it may be that simple, I have never before seen a neutral switch fail in this way. All the other parts were in place, so I fitted a new switch and modified the wiring to suit the spade terminals on the replacement item. I adjusted it to the slightest pressure which resulted in normal operation and will leave it there for now. In the past I have found that in use it required another half turn to continue working when everything was hot. I also removed the plunger which locates each gear on the outer edge of the cam plate, and was pleased to find it hardly worn and the spring pressure healthy. So it all got buttoned up.

While it was easily accessible the end cover came off the starter, got cleaned up and the end bush greased. After that everything got a touch of polish and is complete except for gearbox oil which I have run low on.

This meant that the primary cover could be fully tightened in the knowledge that it was not going to need to come off again. I also fitted the clutch adjuster cover so it could benefit from a bit of polish along with the rest of the cover, which is the largest expanse of alloy on the whole bike.

Starting to look quite smart as things get a shine on. It certainly makes me more enthused to keep progress up.

Tomorrow the oil tank comes back which is great timing, as I need to get some oil into the engine to flush it and to see what state the bottom end is in. Filling that large gap in the frame will make a huge visual difference. Yay.

Final move today was to retension the cylinder head and check the valve clearances. I also removed the two studs which early T160's used for fixing earth wires and the heavy cable for the starter earth current, and replaced them with two ordinary bolts instead. The heavy earth cable got moved to the rear gearbox mounting bolt on later models and I shall do the same.

All the head bolts tightened down nicely and no stripped pillar studs which is always a relief. I noticed the bolts went down further than the 1/4 turn I had loosened them by, so I figured I would need to open up the valve adjustment. Every valve had way too little clearance as I would have expected, but some had virtually none, so I hope I may have found some of the missing compression I discovered on the initial test.

The oil tank came back looking mint, so after filling the gearbox with recently acquired 75W90 synthetic gear oil on it went. The lower mount was still a fussy job, but only half as much with the engine mounting plate absent. I even fitted the badge for maximum effect. Engine mount followed suit, and the earth cable for the starter, after which I poured some 20W50 oil into the tank and kicked the engine over until some black looking oil came out of the oil filter cavity. I kept that up until only clean oil was coming out, then buttoned it up again. Next job will be to see what oil pressure I can find.

Looking a bit more solid with more tin in the picture.

As the starter cover was also in place I decided to trial fit the left sidecover just for the record. I had also fitted the clutch cable as I wanted to position the kickstart lever lower while I was kicking the engine over, and having a working clutch makes that a lot easier.

Here's hoping the oil pressure figures are pleasing, as that would make riding the bike a much closer event. Carbs and exhausts to fettle first, so I won't get too far ahead of myself..

Today I plumbed the oil pressure gauge into the main oil gallery. After a few kicks the pressure began to rise, and kept doing so to the point I was going to be happy. I managed to get an instantaneous reading of 80psi, but unless the kicking continued the pressure would decay quite quickly.

Hence the rush to take the pic resulted in a less than clear image, but you can see it is over 70, which is plenty.

Next job was to strip the rear brake assembly, as the cylinder had seized solid. The plan was to buy a new cylinder and install it amongst all the old bits. The first step was cleaning up the fluid reservoir and line and reinstalling them into the bike. It takes time to clean up every single nut, bolt, washer, housing etc, grease threads and put it back in place, but it is probably the only time these parts have been disturbed since 1975, and they cleaned up really well, so one imagines quite a few years service will be guaranteed before they will need disturbing again.

I do wonder though - when I discover things like this - what sort of previous owner could not only manage to do this, but then leave it like this..?

I straightened the rod and cleaned all the parts up except the seized master cylinder which will be replaced by a stainless item in the not-too-distant. I then fitted evrything clean to the bike so as to position the rear brake pedal away from the kickstart lever, seeing as how it was getting a bit of use lately.

It then occurred to me that I would be able to screw the new master cylinder into the housing while it was already on the bike, so I shall leave it where it is until then. That encouraged me to refit the pillion peg/muffler mounting plate if for no other reason than it had to be somewhere.

Kinda like this...

Next job would be one that requires an awful lot of time and attention if you want a sweet running bike, but it does frankly give me the shits. It is the left-until-last disaster zone known as the carb assembly, and this one was pretty manked. It is not just the carbs that were left to marinate in their own juice, but the entire gantry assembly which was suitably corroded and appeared to have had something like oil baked on it.

Two of the pullrods that lift the slides had locknuts seized to them so I had to dismantle each carb while still attached to the operating bar. Not fun but it can be done.

And was..

So here we are two days later, and I have worn out 3 small wire and brass brushes, sandpaper, steel wool and pot cleaners. Drill bits have been inside every drilling that could shelter ancient snot, pilot jet side drillings cleaned, float levels reset and blah blah.

Fortunately the chokes are not going back on, so that makes reassembly a lot simpler but only eliminates 3 parts per carb, so every other bit gets the treatment. For reasons I cannot explain, sometimes when I strip old carbs I find a slide that has jammed inside the carb body. This was such a time, and it was not grubbage, but a change in the dimensions of either the body or the slide so they have become an interference fit. It is beyond me how this can happen at all, let alone when sitting. The last T160 I restored suffered this same problem, and had what looked to be a bubble in the alloy surface inside the body where the slide fits. This one simply jammed each time it went in unless it went in upside down. I tried two other slides and they were fine in this body, but I could not see where the slide had grown. I filed and sanded and polished until it behaved itself, and the obvious shine on the slide will indicate which carb it was.

I have had enough of this game for a while, so I will work on another bike tomorrow. The results are pleasing enough and despite their poor condition due to storage the carbs seem to be low mileage such as the speedo suggests as 11,200 miles, so I am expecting the tuning will be pretty straightforward.

Now thats a bold statement.

But now I'm back. And I finished the last carb while waiting for a computer to sort itself out. I think this is good enough, as this is a comprehensive re-commission, not a rebuild or a restoration, although it can feel that way at times.

Before the carbs went back aboard I wanted to test the electric starter, which would give me a second crack at getting a photo of the oil pressure gauge at cranking speed. It would also allow a second compression test to see if the valve adjsutments had improved things at all.

This introduced the need for a battery, so I went and got one. I use a Motobatt which is a size reserved for Harleys, and while still being smaller than the battery tray would allow, it is a fairly serious unit. It had no trouble whirring things up to a healthy level..

The compressions had certainly improved, having first presented as 110/85/85, they were now 145/130/125. There is room for more improvement, and it is possible that some may be obtained by putting a few miles on this engine, as it is now being woken from a very long sleep.

As a consequence of some extended engine cranking, the return oil line had now delivered half a litre of oil into the ice cream container which had been perched on top of the starter. The colour of the oil was now that of new, so we had successfully flushed the cooler as much as it could be until the engine and oil got hot.

With that all gone and the oil line returned to the tank it only took a few minutes to trial fit the carbs and airfilter to see how it all worked together. The new manifold rubbers made it somewhat demanding, but that is as it should be. The airfilter needs paint, but the weather is crap for paint right now. No doubt there will be other things to attend to before all this is considered sorted.

I have cleaned the fuel tank under and over, and will hopefully use it for a bit before attending to the paint or that nasty gark on the lower left side. The taps were throwaway, and have been. Besides those we still require another brake master cylinder, a new chain, throttle and possibly speedo cables, add to that the battery and you have a grands worth of bits. Although I have used as many original parts as I could manage there will be at least 2 grand in parts by the time it moves under its own power, and it may remain in that condition for the forseeable.

Sure is responding to treatment though...