Cleaning the Carburetors

Objective:

(post written on the 14th April, encompasses 4 sessions of around 2 hours each)

As written before, the car had issues on high revs and did not reach it's maximum speed. The most probable reasons where old gas (95 octane with almost 2 years mixed with new one half/half), clogged fuel filter and/or dirty carburetors.

Throughout 4 sessions I took care of draining the fuel system and cleaning the carburetors. The fuel filter was not changed as I didn't get a replacement timely. Started by pulling the carburetors out of the car, repeating what I did to remove the vacuum pipes, but this time also taking out the throttle cable and the gas pipes. Took it to my work bench, covered with an old towel. The idea was that if any small part was to fall, it would stay on the bench instead of ricocheting and rolling away.

Following step-by-step the instructions on the Haynes manual for the Fireblade bike, I took away the plastic cover from one side of the first carburetor. Pulled the diaphragm out and disassembled it also.

Then turned the carburetors around, took the metal cover on the other side, exposing the floating bowl and the needles. Removed everything.

Using the carburetor and injector cleaner from Wurth, and following the instructions on the can and scrubbing with a toothbrush and using compressed air to blow dirt around, got it all cleaned up.

Then it was just a matter of reassembling and moving to the next carburetor. The book clearly recommended doing one at a time to avoid mixing parts. Each one took around 1h30m to do... I did this without buying a new rubber kit to replace existing rubbers, o-rings and seals. I should be able to reuse them, no? I was... But carburetors 3 and 4 missed a specific o-ring on the idle needle. Well... If it was working without them there, it should keep working, no?

When all were clean, reassembled the carburetors on the engine. Before connecting the pipes, used the fuel pump to drain most of the deposit, throwing the gas on the deposit of the tintop. All connected, more gas on the deposit, this time 98octane quality fuel, started the car... It works! But the choke now floods the carbs; can't use them. Seems those missing o-rings are needed and all worked before because the clogging prevented the flooding... Did a couple of other odd jobs and added a second jerrycan of fuel on the tank. Put gas until the Digidash said it was 100%. Don't know how "full" that actually is but I didn't want fuel spilt on the floor... The tank should take 23 litres and I dropped there 22 litres. I was ready for the next track day. And it was just in time!