Britbike forum Forums Projects started by Britbike forum members Members bike projects 1966 Triumph T100SR Project

It's a small thing but it's progress. I finally got my 2BA tap in the mail from Steadfast Cycles. I cleaned out the rusted tank threads and mounted the right side Triumph emblem. It changes the look of the whole bike! The left side is a bit more fiddly. One hole has to be carefully drilled out. I have drilled and tapped it for a metric screw but the OEM chrome 2BA screw would look ever so nice.

The seat saga continues. The seat was on the schedule for June the 3oth and when that date came and went I decided to pay them a visit. I knew that they had this coming week scheduled for vacation so I was a bit apprehensive that they would even be open. They were and I actually talked to the owner. He was apologetic, knew where the seat pan was and I did check the instructions and they seemed correct. He put me back on the schedule for July the 7th. I would not have used them but they do such fantastic work I just can't help myself.

I think I am going to use the time to pull the tank and rear fended and possibly give them a light coat of dusty blue keeping the rusty blemishes if I can.

I used my 2BA tap to clean the rusty threads for the tank badges. I still have not put a lick of paint on the tank but the badges make it look better. Oh. . .and I got the bike out and it started first kick and idled too.

I didn't believe that the top end was getting oiled sufficiently. Of course I used assembly lube when assembling everything and I did squirt a bit of 10W40 on the rockers before the first start BUT, when I pulled the inspection caps after the first run (or several runs) I didn't see evidence of oil splash. I pulled the over head oil line back and it too seemed dry. Tonight I cranked the bike, stuck my finger down its oil tank and forced return oil back into the over head feed line. I did get an ooze out of the oil line seal so I know it's getting something. I also know I need better oil line clamps.

The seat is done and I have mix feelings about it. First the positive. It his very comfortable and at the right height for the controls. It is very well made and it is probably period correct for any off road race bike of that era. The negative is it just looks square and a bit slab sided compared to the rest of the bike. The narrow wasp wasted tank doesn't flow into it. It looks a lot like the seat from Steve McQueen's Great Escape Triumph but I seem to think that his tank was a bit wider at the back. I am sure I will get used to it.

It has been so hot out in the shop that I have been neglecting all outside projects. Tonight, as the sun went behind my neighbor's house and it became tolerable outside I got the T100 out. I added a little gas, aired the front tire and took it for a spin. In a surprise, given all the Monobloc carb troubles I have had, the bike fired first kick and idles sweetly. I didn't go far, just up and down the block about 8 times. I am getting used to the shifting. I started off in second gear a couple of time and I might have started in third once as well.

The seat may be ugly but it is really comfortable and makes the foot controls fit wonderfully. My wife, who was watching thought I was going rather too fast. I do not know how fast I was actually going since I have no speedo fitted as of yet. The bike did come with one but it had been sitting outside with a broken glass for over 20 years or more. It's going to need a replacement.

Now that I have run it up I want to go over it and tighten nuts, bolts and screws. I also want to check for leaks and I want to check and make sure the top end is getting some oil.

I took the bike out again today. I got some pictures and a video or two of me making a couple of passes by the camera. I am going to declare the build done. Sure it needs a speedo, a side stand and the tin work needs paint but as far as having a running riding bike it's complete.



Now comes the endless tinkering that is the hallmark of all British bikes of this age.

Well, I said I was done but as we all know that was a lie. I have been riding the bike further afield and waiting for leaks to appear and for items to loosen or fall off. I have not been disappointed. The bike has been reluctant to relight when warmed up and I have discovered that the carb is overflowing again. It's making the bike very rich. The carb has to come off again and I will have to see if there is anything I can do to improve the sealing of the needle seat.

I finally got around to pulling the carburetor back off again. Bear in mind that this is a AMAL Monobloc. The bike starts and runs fine but the last few sessions it is been overflowing. by overflowing I mean it has started dripping, which is something it never did. Before I opened up the side cover on the float chamber I removed the needle seat. The first think I noticed was the float could moved from one side to the other as much as an eight of and inch. This was enough to disturb where the needle was riding on the float ramp. I opened the carb side plate and found the float pivot pin was sloppy lose.. I fixed this by pulling the pivot pin and dinging the hole with a punch.

I have been fitting a small spring in place of the float spacer to keep it in its place. I hope this all works.

A few things I noticed as I went through the float/needle seat with a fine tooth comb. As I mentioned before, when I pulled the needle seat and looked down on top of the float I noticed that the float could moved from one side to the other as much as an eight of and inch. I don't think that this was a show stopper but the needle rides on a specific point on the float (as evidenced by the worn divot) and lateral movement can't be helpful. I am going to use a very light but nicely fitted spring on the float pivot shaft in place of the spacer. This will keep the float from shifting without hindering its movement.

The second thing I noticed was float was actually hitting the top of the float chamber at the point where the needle was supposed to be sealing. There is no adjustment for this other than a longer needle. I took a spare needle, drilled a very small hole on the base and added a drop of JB Weld. Then I sanded this down until I was close to the original float placement. I used a piece of paper, placed on top of the float, to draw out and make sure there was no resistance.So now, the float closes the needle seat without hitting the carb body.

the spacer on the outside , prevents the float from catching on the side-cover .
I seen that go missing on Monoblocs , glad to see that you have it covered , but don't think a spring is it all necessary .

The one monoblock I have works fine 90% of the time , but occasionally leaks , usually after a long layup .
my solution is to tap the cover with the handle of a screwdriver .

the leaks usually happen when the bike isn't running ... because , I suppose , a running engine
Provides enough vibration-wiggle to seat the needle .

There's actually a couple more ways to fix that problem besides your solution.

Machine the underside of the float needle seat where it seats against the top of the float chamber.

Or, carefully solder a thin piece of brass to the float right where it pushes on the needle.

I was just kind of shocked at the spacing between the top of the float chamber and the float. No wonder it had a dribbling issue and with zero adjustment capability. It has been my observation that, while the Monobloc has the metering capability of a tin can with a straw in the middle, great care must be taken to assess the details of the design. Any little thing can keep it from functioning as intended.

the original monoblocks fitted through 1967 do not use
A sealing-washer ... between needle seat and zinc carb body .

later reproduction monoblocks ( that are otherwise totally backwards compatible )
do use a sealing washer . ( and a rebuild kit may come with this )

Adding a washer to an older monoblock will screw up the needle seat level .
( incorrectly raising the needle seat , by the thickness of the washer )
If you've added a washer here , this could be your problem .

It has been a while. I think I have the Monobloc situation figured out. It still leaks a bit but only after it has been sitting and if I turn the petcock off before shut down it is minimal.

I changed the oil. This is the first oil change since rebuild. I also changed out the rubber oil feed and return lines. I had used plain fuel line but replaced this with transmission cooler line just to make me feel better. It's a much better fit and I used new hose clamps for a better seal. The oil ones were weeping a bit.

It runs great, fires right up without tickling and idles pretty good. The plugs look ashen grey after a putt around the neighborhood.

I am at a bit of a loss as to what to do now. I finally got the paper work on my Norton straightened up and I have a real Texas title and tag for it. I have been riding the Norton now. I guess I could tear the T100 back down but I have never been great with actual restorations. I get bogged down in the minutia and almost terrorized by the fear that I might be messing something up. I almost feel like it would be in better hands of someone whose passion was visual restoration.



I feel pretty good about the oil change and the oil pipe replacement. I seem to have contracted a case of bronchitis while I was a Barbe Vintage Days, two weeks ago, and today has been the first day I have felt up to doing much of anything. I have had a wicked cough that has made even sleeping very difficult.

It's nasty, iced over and cold out side. I am so bored that I am going out of my mind but something monumental happened today. My blue Texas title for the T100 came in the mail. It's like Pinocchio becoming a real boy!

I also sent the head off to have valve guides installed. It is the one thing that has been driving me nuts. (I knew how worn out the guides were.) I didn't want to drop a valve and ruin the work I had done since I actually want to ride the bike. I have no idea when I will get it back.

When it was a little warmer I wired in a kill switch. It looks horrible and modern but it can't be helped with the electronic ignition. I can't just ground the coils with a kill button.

I know I said I was done but are projects ever really done?

I got the head back from Randy Long in PA. He does a bang up job as quite a few BMW and Moto Guzzi owner will attest. He installed new guides and new exhaust spigots that replace my old rusted nasty ones. I have it together and it runs really nice and the top end is a lot quieter than before.

Now comes the tricky part. When the bike is running and I turn on the headlight the bike dies. In addition the horn stopped working. I thought it was a ground issue but I checked that and so far I have found nothing amiss. I will have to dig deeper.

Yes, the battery is fully charged. No, it never did this before I had the head off but of course I didn't touch the headlight so maybe it did and I didn't know.

Edit (A short time later) I lied. I cheeked the battery with the multimeter and I was showing just over 10 volts. The batter is dead or toast. We will see if it will take a charge. The reason I said it was charged is I had it on the trickle charger and it showed green.

I am going to need to investigate more thoroughly. When I left the bike, before the head work, I could swear that I had over 13V charging output. Now it seems that, after charging the battery, I have only 12.34V I had my daughter help me hold the multimeter and the test leads. The battery shows 12.34V with the ignition off. Running the voltage jumps all over the place from 9.52V to 10.37V. Honk the horn and the voltage shows a little over 14V. It's nuts.