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Fuel system design ?
mcerd1 - 29/9/17 at 03:58 PM

I'm about to order the last few odds and sods to finish my fuel system - after spending far too much time and effort building the engine it would be nice to get running
I'm probably over thinking this but here goes......


I'm going to be using ZX9R carb's (keihin CVR's from a model 'E' ) (Pic linky)
These seem to have two ~10mm inlets (one for each pair) linked together with a plastic Tee.

The pump I've got is also form a ZX9R (earlier C1 model) and also has ~10mm (maybe 3/8" inlets and outlets, but the OME filter fitted on the inlet side is only ~8mm (with the 8mm hose to the pump stretched over the pump inlet)
ZX9R Pump
ZX9R Pump


I was planning to use at least one of these filters before the pump, as it turns out these fit quite nicely in the ZX9R's OE mounting:
https://www.merlinmotorsport.co.uk/p/sytec-10mm-in-line-fuel-filter-ff-inl-6

Unfortunately the outlet on the tank I've got is ~13mm O/D - which is a bit much for a 3/8" hose to stretch over
Dax tank outlet
Dax tank outlet



So I was thinking about using a short length of 1/2" flex from the tank, followed by an adaptor down to 3/8" and them onto the filter and then to the pump (all 3/8" )

then I could run a 3/8" or a 5/16" flex from the pump to a copper or cunifer pipe (3/8" or a 5/16" to the engine bay - then another 3/8" or 5/16" flexi to the carbs


can anyone see any problems with this ?
would the 3/8" pipe be better than 5/16" for the main run down the tunnel ?
do I need to add a post-pump filter as well as the pre-pump one ?


r1_pete - 29/9/17 at 09:29 PM

Sounds fine, Ive done several now in 8mm cunifer 5/16 equiv. You can solder 8mm olives on the ends to prevent blow off or vibrations working the pipes off.

Id put a small filter close tomthe carbs, the little screw together alloy jobbies work well, and can be cleaned.