Has anyone taken an injection bike motor that normally requires a return to the tank and utilised one of the clever in-tank pumps from one of the other manufacturers (like Kawasaki) so that they only have to run a single fuel line?

Worth doing, if you have the pump already?

Ta

Edit due to grammmmmmaaar!

[Edited on 7/9/10 by TimC]

We run a Honda in tank pump and regulator in the Formula Student car. Seems to work a treat. Initial startup after it's been apart takes a little while as it clears all the air out as you might imagine but seems fine after that. Certainly far simpler to plumb, particularly if you are going from a carb'd setup to injection.

Only issue we had was it falling apart in our own little swirl pot thats bolts to the bottom of the tank having taken it apart from the fuel level indicator.

You don't have to use a special pump, you can rig it like this using a normal pump and reg. This is effectivey what the in-tank pump is doing anyway.


Feed only injection fuel sys

The above, or an in tank pump, would work fine with any injected engine which is mapped for fixed fuel pressure (i.e. doesn't have a vacuum line to the fuel reg).

[Edited on 7/9/10 by matt_claydon]

Regulators on the fuel rail are connected to manifold pressure and regulate relative to that.


In tank regulators regulate relative to ambient air pressure.

Changing the type of regulator will knck the fuel mapping a mile out, this will be compensated for by fuel trim when running closed loop, but not when open loop.

Tim,

I took a carbed bike and put EFI on it. Using the regulated pump in the tank. Works fine. I don't see why it would not work equally well on a motorcycle engine that had a more conventional return line.

Regarding regulating the pressure in the tank versus in the manifold. This may be relevant in some installations, but in ITB applications with bike engines you don't get much pressure variation (surprisingly enough maybe -5psi at idle, and atmospheric once the throttles are opened more than a crack) so (unless you have a turbo) this might not matter too much.

The only gotcha would be if you are running secondary injectors. In this case they only flow fuel some of the time, and you could get some overheating effects in that section of the fuel rail. For this reason you would want the secondary fuel rail to be "on the way" to the primary fuel rail. Perhaps not an issue.



The only problems with these in-tank pumps are the mounting (welding fuel tanks and such), and the fact that there is no facility for an after pump swirl pot. The pump itself includes a filter, and the pressure regulator is at the top of this filter, so that will help remove the air, but its the sort of thing that worries me a little. The benefit of simplicity is always nice though.

Matt

Cheers all - I shall be more explicit - 5VY R1 using an early ZX12-R pump (which I have, along with a nice ali flange to be welded to a tank)?

Tim, it might be worth checking which fuel pump you actually have. The early ZX12R's, (2000-2002) did have a fuel return system.

From 2002 onwards (the 'B' models) fuel pumps were re-designed to eliminate the need for a return feed.

Phil