30-12-2021, 10:20 AM
With the 22FZ & 22 FZB carburetors I have found that a lot of the slow running screws are splayed out and split where they touch the slow running jet by being screwed down tight, replacements are available from Willie Mackenzie.
slow running jet assembly. I've yet to find a carburetor mounting flange and the manifold mating flange that are flat being bowed like this fuel pump flange.
. Then with these attended to I check the float chamber fuel level with a test rig like this
. It is easy on the mazak 22FZB to see the fuel level in the main jet cover by taking the top off the carburetor not so easy on the one piece bronze 22FZ, it should be 1mm mm below the top of the main jet cover as so
Carb Comp 1.jpg (Size: 32.79 KB / Downloads: 140)
and is adjusted by sliding the collar on the needle valve up to lower the fuel level and down to raise it. Due to the design a it is not a 1:1 ratio and the collar only needs moving a small amount. The collar is usually locked with solder so needs heating to release it. I should have added that to do this correctly the needle valve must seat and shut the fuel off as any leakage will confound the issue, I use T cut to re seat them never grinding paste,
Carb Comp 1.jpg (Size: 32.79 KB / Downloads: 140)
and is adjusted by sliding the collar on the needle valve up to lower the fuel level and down to raise it. Due to the design a it is not a 1:1 ratio and the collar only needs moving a small amount. The collar is usually locked with solder so needs heating to release it. I should have added that to do this correctly the needle valve must seat and shut the fuel off as any leakage will confound the issue, I use T cut to re seat them never grinding paste,