Featured Resurrecting 1966 Tiger T100ss

While waiting for the fork legs to be delivered (in August) I started looking at another large job that needs to be jobbed, namely the petrol tank and mudguards and painting. I know that they have their own problems but thought I need to make a start on them. Needless to say there’s more to do than I thought. Why is there never anything just straightforward?

The bit I knew about was a broken off screw end in one of the parcel grid holes, which has been soaking in WD40 for the last couple of months. I’ve looked inside the tank with an Endoscope and it shows very little by way of surface rust, but there has at sometime been a leak at the back corner opposite the opposite the tap. There are threaded mounting plates welded on at each corner and a hole through the tank right under the right hand one. The weird thing is though that the plate seems to have been cut off and re-welded back on again and a load of filler applied under it. And to cap that, it seems to have been welded on the wrong way round, at least the bolt hole is too far inboard and doesn’t line up with the mounting bracket. I guess I’ll have to cut the plate off to get the hole welded up Oh joy!

The broken stud end is defeating my efforts with an easy-out, even with heat applied. I don’t know how much force it’s going to take before I break it off. I’ll have to think about this a bit before I try drilling it out and completely f*** the whole thing up. Back to the forks in the meanwhile.

 

The broken parcel grid screw finally succumbed to a left-hand drill which I bought at last Saturday’s Kempton Park bike jumble. Giving it short bursts with the power drill brought most of it out in one piece. Re-tapping cleaned out the remainder of the thread but the so-called easy-out has not done the top few turns any favours. I must have been a bit heavy handed as they are not looking great. Even the easy out twist is mullered.
Onto the damage at the rear tank mounting. I’ve cleaned off all the rubbish around the mounting plate. There’s a considerable amount of filler or possibly Plastic Padding around and between the plate and the tank itself. All the exposed stuff chipped off but I can’t get to that under the plate. Removing some of it I found a small patch of green paint that looks suspiciously like Sherborne Green, the correct colour for a ‘66 Tiger 100. At least it looks like the tank is actually the original one for the bike.

Looking inside the tank I can see that there is what looks like the end of a bolt sticking through the tank which has been cut off on the outside and is now covered by the mounting plate which has been welded in a**e about face to cover it. All four bolts for the tank should be the same length with a short thread to engage with the mounting plate and have a shoulder to prevent them from being screwed in too far an penetrating the tank itself. None of the bolts I have, have a shoulder, but have varying lengths of thread. No two are alike.

So, at some time in the past one of these bolts has been wound in far enough to penetrate the tank, a repair of sorts has been done to plug the hole with a cut off bolt and filler and the plate welded back on to cover it up. At some time later, someone (else?) has done exactly the same thing making a second hole alongside the first.

I’ve now managed to cut through the welds and removed the mounting plate to reveal the full horror that lies underneath. The bolt end is screwed right through the tank and brazed into the mounting plate. A second bolt hole has been drilled and tapped inboard of the original and the whole thing plugged up with some sort of sealer.

I’ve now got a welder lined up who’ll have a look at it and a new set of rubbers, cups and the correct bolts on order.

 

I Wish…

Another curved ball. I just received the new petrol tank bolt kit. I got them from a supplier that offered L F Harris kit so I would be pretty sure of the right stuff.

As the bolts that I have all screw into their respective holes I didn’t realise that anyone might possibly have drilled out the holes and re-tapped them for a larger bolt. Bolts that are not 26TPI incidentally. There’s no mention of the bolt size or thread in the parts list or w/shop manual so it is something of a surprise to find that my beautiful L F Harris bolts just drop through the holes in the mounting.

Which means that the welder is going to have to weld up all four holes for me to have to re-drill and tap out to the correct size.

 

I had eventually cut through the welds and removed the R/H rear mounting plate that covered the holes in the tank, to find the extent of the damage caused by over enthusiastic tightening of the retaining bolts which had punctured the tank itself. The other three holes in the mountings had been enlarged and tapped for 3/8in bolts instead of the 5/16in standard. I’ve now made up two new rear mounting plates, drilled and tapped for the standard size.

The tank has now received the attention of a welding firm who removed the other mounting plate to check for any similar damage under it. They repaired the damaged tank, and then welded in my two made-up plates, leaving a clearance space for the end of the new bolts. They also welded up the oversize front mounting plate holes and drilled and tapped them for the correct sized bolts.

Also welded up was one of the two plates on which the tank sits. The holes in this had had been enlarged on the outside edges, with a large scallop cut out where the mounting rubber sits, presumably to accommodate the bolts, of which one had been moved about a half-inch inboard in the previous ‘repair’.

Dave

 

Thanks Baza.

 

Following along in the ‘fuel’ related theme while starting the cleaning out of the repaired fuel tank, I’ve turned my attention to the carburettor. The parts catalogue tells me I should have an Amal Monobloc 376/273 with a 1inch Venturi diameter and a manual choke lever. That is the weirdly shaped, Pull-me Push-you bit of rod sprouting out of the top of the carb that operates the choke

What I’ve actually got, is an Amal Concentric A626/R68 with a 27mm Venturi which has a cable operated choke from a control on the handlebar. It tends to lend further confirmation to my ever growing suspicion that the pile of bits I’ve bought into is no more than a collection of bits brought together from jumble traders cast offs. But, another weird thing though, is that the Concentric may well have been in operation on this bike because both the throttle cable and choke cable are present and still attached to the handlebars ready for connection.

The Concentric was not actually standard equipment for a ‘66 T100 but as the Monobloc was replaced with Concentrics throughout the Triumph range during the next couple of years it’s probably an acceptable replacement. It’s certainly a lot cheaper if buying new.

Nevertheless, I’ve been keeping a weather eye open on EBay, for a suitable Monobloc carb that can be overhauled and will fit. The question is though What to look for? As the details given by sellers is usually sparse and often don’t include the most important information like type number and Venturi size. Eventually I did find a Monobloc with the very similar type number, 376/231. On the face of it that would seem a likely replacement for the correct thing with such similar numbers, but before parting with a sizeable wedge I thought I’d try to check out what the numbers actually signify.

Long story short, I referred to the Triumph Owners Club forum and received some helpful answers. It seems that the Concentric I have was originally the right-hand carb of a bank of three on a T150 Trident and the Monobloc on offer is from a James or Francis-Barnett 200cc two-stroke. Where things get really heavy is that on on 2-stroke carbs, particularly the Concentric, the spray bar has a different cut-away for some applications which can cause running problems if used on 4 strokes.

So I guess I’ll just have to bite the bullet and go for new. But that’s for another day

 

Yes. I’d pretty much decided to go that way. It is more expensive but i suppose that at least it’ll minimise the likelihood of any further problems due to incompatibility. The Concentric I’ve got is pretty much junk anyway. It’s badly corroded inside and the centre body broke up when I tried to get the main jet out. It’s Venturi size isn’t quite the right size 1” anyway.
Dave.

 

Yes. I’d pretty much decided to go that way. It is more expensive but i suppose that at least it’ll minimise the likelihood of any further problems due to incompatibility. The Concentric I’ve got is pretty much junk anyway. It’s badly corroded inside and the centre body broke up when I tried to get the main jet out. It’s Venturi size isn’t quite the right size 1” anyway.
Dave.

Btw. I’m cleaning out the tank atm. Were you being serious when you mentioned that you used a cement mixer ?

 

Right, thanks.
Luckily the inside of the tank isn’t too bad for rust and the metalwork is quite sound.
I’ve offered up the tank and bolted it in place. I’ve just got to take a slight ‘shaving’ off the new (my) welded on plates where they just foul the frame bracket.

I’ve got a couple of gallons of vinegar on order.

 

I dug out the Speedo and the Rev Counter clocks to clean up a bit and assess. They aren’t quite a pair though. On most pics that I’ve seen the clocks have matched faces but on my two the rev counter has what looks like a decidedly faded face, almost a uniform grey in comparison to the speedo. In view of everything that’s occurred so far to the parts that constitute my ‘pile’ and I’ve already partly dealt with, this should come as no surprise.

In this case though I can accept that there might be a reasonable explanation. Going by what documents I’ve got on the bike it appears that T100’s were not originally supplied with a rev-counter as standard. If the bike was ordered up by the original owner with a rev-counter it was at that time common practice for it to be supplied with the bike as an accessory and installed by the dealer at Pre Delivery. The record of the delivery shows that the Rev Counter was ordered up as an accessory.

They are both intact otherwise but I can’t say if they are actually functioning. Most pictures show that the casings of both clocks are painted black, even those taken at around the time they were the current model. Needless to say my two are different. Both are unpainted and have a straight Nickle plated finish on the casings.

I’m afraid that repairing these is beyond my pay code so I’ve been looking for a man that can. I’ve found a gent with recommendations who is not too far away and have now taken the clocks to him for attention. He’s going to do what’s necessary including replacing one of the cracked glasses, paint the casings and keep the recorded mileage on the speedo. Apparently they should be ready in about a month.

Dave

 

I thought that I’d try something that should be fairly straightforward this week, that would be reasonably easy to do and would show some sort of progress with a minimum of effort while I’m waiting for the petrol tank to pickle. So, shock absorbers. Slide ‘em in, four bolts, bish, bash bosh, done. Easy. What can go wrong?

I’ve got three pairs of shock absorbers from ‘the pile’. First pair, which are possibly the originals, and have shrouds, which have been taken off, are greasy, dirty and probably seized. The shrouds and fitting bits are rusty and I can’t get any motion out of the damper at all. The second pair aren’t shrouded, the springs are exposed and rusty and also don’t move much. But they do have a set of bolts in the eyelets and I suppose may have been on the bike at some time. The third set are a pair that I replaced from the Bonnie about twenty years ago and they were a bit iffy then, so they’re not going to be much better now.

All in all they are too far gone to do very much with. Without a rig to strip these things down there’s no real likelihood of me refurbishing or calibrating their efficiency to an acceptable level, so I was always going to simply replace them with new. I was able to buy a new pair at a reasonable cost together with a set of new bolts to show them off and set about cleaning up the old bolts while waiting delivery.

According to my ‘Boy’s Own Book of Bolt Identifying’ the bolts turned out to be original equipment on a ‘66 Tiger and are apparently sought after by enthusiasts for their originality as the manufacturer’s name ‘Bradley’ is cast into the reduced size head. At least, three of them did when the muck ant rust were cleaned off, but the fourth was a fairly ordinary and similar sized 5/16 bolt.

Nevertheless I had cleaned up the frame fittings and offered up the new shockers into place. After a bit more cleaning up I got the bolt holes aligned and tried to fit the new bolts into place. They just would not go into the shocker beyond the threaded end. Back on the bench it was still the same although the original Bradley bolts went in quite easily. After measuring up the holes and bolts I found that the bolt’s shank were just about the same size and there was a slightly wider ridge where the thread finished. More cleaning up with a fine file and emery cloth got rid of the ridge and gave a clearance to the bolt in the eye.

It finally came together.

 

Thanks Baza . This would not come as any surprise. It would just be another gift from the restoration that just keeps giving.

Dave