Carburetor Tuning Updates and New Clutch Master Cylinder

Cleaning up the spark plugs early in the morning

Normally, the engine runs a rich air-fuel mixture due to the poorly tuned twin side draught Mikuni PHH40 Type T's. I've been struggling with the carburetor balance and pilot screw settings, which results to a dark sooty layer on the spark plugs. But when I inspected the plugs this morning, all the plugs had a tan to light brown color. This indicated that the air-fuel mixture was balanced and the Mikuni carburetors were at the optimal air-fuel mixture settings.

I hope this air-fuel mixture tuning can be sustained for better fuel economy and performance.

When I was driving last night, I did notice an improvement in engine performance especially with regards to torque. The engine "pulled" better, which meant faster acceleration on the highway. I really hope this optimal air-fuel mixture setting doesn't change at all!

Finally, a light brown color on the plugs, which indicates a balanced air-fuel mixture.

Surprisingly, the spark plug in cylinder two also indicated a clean burn, since it was always fouling due to a rich carburetor setting. I'd always clean the plug, since it was covered with unburnt fuel and wouldn't fire at all.

New Sam Clutch Master Cylinder (Japan made)

I also recently replaced the clutch master cylinder, since it was always leaking at the fire wall. Being that brake fluid is highly corrosive this is really bad, since the fluid will literally "eat-away" on the metal parts especially the left inner fender and the firewall. So far no signs of leaks with the new Sam clutch master installed. Pedal feel is still light, which is good for stop-and-go traffic.