1970 Triumph TR6 Restoration

If the gas tank looked like that, chances are good that the rest of the fuel system, especially the carburetors, could also use some attention.

The “Resources and Guides” page on this site has links to a series of carburetor related articles written by Nelson Riedel of Buckeye Triumphs. I highly recommend these to anyone who plans on rebuilding their carbs.  Since these cover carburetor theory, I won’t go into much detail here.

Both Carburetors (Air Cleaners Removed)

A bit grimy. It’s best to work on these one at a time so that you’ll have a model and parts won’t get mixed up. All of these pictures are of the rear (left) carburetor.

Intake Side

This is where the air cleaner attaches and fresh air is drawn into the carburetor.

Front (Closest to Grille) Side

This side has the Temperature Compensator and Bypass Valve attached to it. Both of these help to regulate airflow in the carburetor.

Manifold Side

This side bolts to the manifold and is where the fuel-air mixture leaves the carburetor.

Rear (Closest to Boot) Side

This side has the clutch (cold start valve) on it. Notice the classy screw-in-tubing replacement for a cap on the left.

Alright, time to start taking this thing apart and cleaning it. First up is the damper assembly:

Diaphragm and Spring

Damper Assembly

All the pieces laid out. I took the diaphragm off the damper to replace it with a new one after everything was cleaned. The needle was cleaned but not removed.

After that, I flipped the carb over and took apart the float chamber. This is where the fuel comes in to a reservoir prior to being mixed with the air.

Float Chamber

Once this was disassembled and cleaned, I pulled the rest of the components off the sides of the carburetor.

Choke Assembly

Temperature Compensator

Bypass Valve - Front

Bypass Valve - Rear

The bypass valve opens and closes based on air pressure to adjust the fuel-air mixture in the carb. The once flexible diaphragm in this one had become completely stiff.

Old Bypass Valve Diaphragm

All parts were cleaned thoroughly and all the diaphragms, o-rings, washers, and seals were replaced. Here’s it all put back together and ready to go:

Bottom

Choke (less blurry)

One Down, One to Go!

When I did the second carb I soaked it in a degreaser that turned it dark gray and left crystals all over it, no matter how many times I rinsed it. I don’t think it will affect performance, but it was a bit unnerving.

I also flushed the metal fuel lines with lacquer thinner and replaced the fuel filters (one was added between the fuel pump and carbs at some point) and rubber portions of the fuel line. The fuel pump looked like it had recently been serviced, and was working, so I left it alone. There’s enough to fix as is, no need to go looking for more.

I still need to finish tuning the carbs, and from what I understand this can be a perpetual process. There is also something funky going on with how they are hooked up. I don’t think these were the original carbs, and believe that they may even be from two different years. The vacuum advance/retard lines may also be swapped, which may mean that the carburetors themselves were swapped. Sometimes there is more work in un-doing than doing.

This is a writeup I did last fall when I restored the fuel tank. It was a lot of work, and it seems to be holding up well so far.

One of the first things I did after receiving this car was to restore the fuel tank. The tank had gas sitting in it for a long time, and was very rusty inside. There was no way to try and fire up the car with this crap in the tank, so I set about cleaning, sealing, and painting the tank to prep it for fresh gas.

The Gas I Drained Was Rank

The gas had been sitting for a long time and was full of gunk, rust, and water.

Outside of the Tank

A little dinged and definitely needs a cleaning.

Tank and Rust

The pile of rust in front of this picture was what I shook out before I even tried to remove rust.

The Rusty Innards

I bought a fuel tank repair kit made by POR-15, which included a couple bottles of Marine Clean, a bottle of Metal-Ready, and a can of fuel tank sealer. It also came with a jug of fuel stabilizer to use if the car is going to sit with fuel in the tank for a while.

I started out by alternating between rinsing out the tank with water and dropping a couple lengths of chain into it along with a handful of rocks and shaking it around like an angry ape. I’m glad we have tolerant neighbors because the sound was horrific. It did a good job of knocking the rust loose though.

After most of the loose rust had been rinsed out I sealed up all the holes on the tank and dumped in the Marine Clean, an industrial strength degreaser/cleaner. This time I alternated between letting it soak in various positions and shaking it like an angry (though much quieter) ape.

After shaking/soaking for 24 hours I did a bunch more rinsing until the water ran out clean. I let the tank dry, then plugged up the holes again and dumped in the Metal-Ready. This stuff dissolves any rust in the tank, etches the metal, and coats everything with zinc. I did the usual shake/soak for about 2 hours (I have never seen something listed as fast acting live up to its claim), then drained off the Metal-Ready (it’s re-usable if you filter it) and rinsed out the tank a bunch more.

Here’s what the inside looked like after the Metal-Ready treatment

After getting the tank bone dry and once again plugging all the holes, I poured in the can of tank sealer and slowly tilted the fuel tank to make sure all of the insides got coated. The tank isn’t just empty space inside. It has two vertical panels with a slot down the middle of each that separate the tank roughly into thirds. These are there to cut down on sloshing fuel while driving and also to make repairing a tank more difficult. I turned the tank around a few times until I thought everything was coated, then unplugged the top, flipped it upside down, and let the excess drain off. The sealer looks like a clear viscous resin with silver particles suspended in it. It behaves much like superglue.

The Inside, All Coated

The sealer doesn’t give the most beautiful or even finish, but it’s tough. I thought that I had missed some areas of the tank, but it turned out that they were coated with just the clear part of the sealer and didn’t get as much of the pigment.

Finally, I cleaned the outside of the tank with this rust remover that takes forever and is a huge pain to rinse off, and then painted it.

The Finished Tank:

For Comparison: