Bit of history,

2001 engine, running stock fuel pump fitted as per bike under throttle bodies, this takes it feed from a swirl pot on scuttle. As run perfect for 18 months in this configuration.

About 6 weeks ago I had a misfire under load which turned out to be 2 dodgy injectors, or at least changing 2 cured it may have disturbed something ? I believe it was fuel related as both plugs where showing as running very lean.

Well was at Anglesey yesterday, (great circuit) and the problem as reoccurred, definitely running lean looking at the plugs, on tick over you can hear each cylinder drop off when plug lead or injector lead is pulled definitely runs on all four on tick over, you can also see bucket loads of fuel going down each port when rev'd but engine temps have increased also indicating running lean ?

So question ?

Rather than keep chasing the problem with stock gear do I change the fueling set up and if so what to, recommendations please.

What's the cause, fuel pump, (not checked pressure) ? Injectors dirty ?

Do I ditch the stock pump, its big and ugly, also do a ditch the std fuel rail if so what do I replace it with ?

Jon, have you got a Power Commander or similar fitted, or are you running the stock fuel map?

Phil

Stock map, thing is it's been fine for over a year, am seriously thinking of a power commander but 1st want to get decent fuel system in place, pretty sure it's fuel related

Can you be certain that it hasn't always been running lean? Most BEC's do tend to run lean on a standard map..... Personally, if I had the Busa engine fitted, I'd go for an FI Tuner Pro from Healtech to enable fuelling to be adjusted. If it's anything like their other products, you'll not get better VFM.

Phil

If you are running the old style non tank fuel pump, there is a good chance that the filters in the pump need changing. this is quite common on the original pumps. the later type Busa's ran an in tank set up. which is what I have on my car. You could consider changing to this type but it would require changing the fuel line to a single flow with no return. The pressure regulator is also built in to the new pump so the engine end is much tidier with no other parts.

I assume you have no problems with this set up, air lock at end of fuel rail for example, like the idea of cleaning engine bay up this way.

eta

What sort of depth are they when fitted, is it obvious once you have a pump in your hand how to adjust the pick up to reach bottom of tank ?

Filters, guess there is one in pump ? Did/do you fit one externally in line also just before fuel rail maybe ?

[Edited on 5/4/11 by Jon Ison]

[Edited on 5/4/11 by Jon Ison]

When I spoke to Jack Frost from Holeshot about mine he expressed surprise I hadn't run into trouble with my '99 FI pump (like yours). He reckoned they often ran lean. He uses a separate Bosch pump + reg but I went for a stock in-tank pump in a swirl pot.

I think a pump swap is in order befroe I do anything else, like the single fuel line idea and for sure will tidy up things under the bonnet.........

So, as above how easy is it to retro fit the later pump into my "nearly new" tank, dont mind cutting a hole to mount it I guess in the top ? fuel pick up ? filters ?

quote:

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Originally posted by Jon IsonSo, as above how easy is it to retro fit the later pump into my "nearly new" tank, dont mind cutting a hole to mount it I guess in the top ? fuel pick up ? filters ?

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Later busa pump sounds like a decent plan. The only issue is that the filter is integral and I don't know whether they can be easily changed.

I went this route (gsxr1000 pump, but same principle).
I can't weld aluminium so made up a simple annulus of aluminium, which with appropriate grooves, 'O'-rings and tapped holes allows you to bolt the pump up to the underside of the tank (like this).




Just a thought. This isn't any better than a welded sump solution, but was a different way of doing it.

Thanks for all the info hints and tips, particulary one guy whom as helped via u2u and phone, I have sourced a new pump tank is out the car been modded will keep you up to date what happens from here......