I used the Mikunis too, they ARE cheaper.
However, I was concerned by the amount of fuel they could deliver and was worried about over-pressure..... so.....
I made a complex arrangement. The fuel flows from the tank to each pump in turn (not to each pump, separately). The exit from the 'fisrt' pump arives at a 'T': one exit of the 'T' goes to the first carb and the second goes to the other fuel pump. The other engine also has a 'T' but this time, one goes to the carb and the other returns to the tank. We thus have a full pump and return system.
I was also concerned that too MUCH fuel much return to the tank so I restricted that final pipe (the last pipe to return to the tank) by inserting an old carb-jet into the fuel line, thus allowing most of the fuel to return but making sure that pipes wsere slightly pressurised. This made sure that the fuel pump pressure would not not 'blow-off' the needle valve in the float chamber of each carb. You could simply put a small in-line-tap (Demon-Tweeks sell them) in that final tube to control, the degree of 'restriction, if you prefer.
The final tweak was a good one. Go to any boat 'chandler' (shops which sell boating equipment) and buy the strange 'bulb' they fit in the line between the fuel tank and the engine. This let's them pump the fuel from the tank to the carb once they reconnect the motor. It 'primes' the carb. Now, fit this bulb alongside YOUR tank in nthe frist pipe from the tank to the first pump. This ensures that, once you have changed a motor, cleaned the carb, run ouyt of fuel, etc., you can INSTANTLY return fuel to you carbs, even from a TOTALLY 'empty' system.
We learned that one from a VERY delayed fuel stoip, mid race when we had run out completely. Trying to get the fuel UP to the carb took MUCH longer than re-fuelling and cost us HUGE amounts of time! The 'bulb' pump eliminates that proiblme PERMANENTLY!
Out of interest, the bulb is quite strange.... it has ZERO effect on the fuel flow rate when the bulb is NOT being squeezed. Until you use the bulb, it has no effect whatsoever on the system.
Oh.... and buy a second bulb as a spare. Fit that in the middle of a spare fuel pipe and then you have the perfect 'siphon' for emptying fuel from you tank after a race..... or raiding someone else's fuel from their car while they are not looking......
Oooops... Doh!....what am I SAYING here.......
ian
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