[ultraflo]

Dittos on the refill when it's half full... no prob.

IMHO, one step colder plugs should be fine w/ a 75 shot... but by all means you could try 2 steps colder, motor will idle a little richer... just be sure to check one or more plugs when you get to the end of the track (shut the motor off when you cross the 1/4 to get an accurate reading)... you could also invest in an EGT gauge to monitor your exhaust temp.

Plug gap? I run .035, haven't tried any larger... If .041 works for you then keep it there.

If you followed the Zex's instructions to the "T" then you should be fine as far as following their recommended tune-up... I'm not familiar with the Zex kits. I wouldn't run any less than 10* and run 93 octane pump gas or better.

Have fun!