F4 tank on F4i
 

I have an F4 that I'm contemplating converting to fuel injection (thus F4i head, TBs, and airbox). People keep saying the fuel injection conversion REQUIRES the F4i tank, but is this due to fitment or fuel pump?

If it's just because the F4i has an internal fuel pump, then I would really rather just keep the F4 tank (free) and use an external pump and regulator.

If it's because of fitment, what exactly hits? Would it be possible to "dent in" the fuel tank in such a way to make it fit?

Thanks,
Chris

anybody... ?

a month later and still nobody has any idea?

I haven't had access to an F4 to tear apart and compare differences.

Just thinking out loud here: So you will need a F4i ECU to run the fuel injection. The ECU is going to look for the F4i fuel pump or at least a fuel pump that is connected properly which most likely means you will use a F4i OEM harness. Wouldn't it just be easier to slap a F4i tank with a F4i fuel pump already in it and wired up on the bike rather than try to hassle with a exterior fuel pump? I know this mean you might have to get it painted but you can sell your F4 tank to recoop some of the losses and I think this would be a easier solution maybe? As far as space goes I truly have no idea as I have not worked on any F4's in my day.

Chris are you looking for a project to do or maybe do something that is different or do you just want a FI bike. If you want a project or want something different well then good luck to you, I wish you the best. If you want a FI bike just sell the F4 and pick up a F4i. Way easier.

You would need a different ECU. Otherwise what's going to get the pump and injectors to work properly?

And just sell the f4 and buy an f4i, 'tis easier.

Well in addition to the cost of buying a new tank, I'm also concerned about the stock F4i pump flowing enough fuel. The bike is going to be a turbo bike and as I can't seem to find stats on the flow rate of the F4i pump, I'm inclined to go with an external pump. The F4i computer does not "look" for the pump (it has no clue if the pump is present or not...), it only switches a fuel pump relay to ground.

The bike is a project bike. I got it for $200 (it was 50% apart due to sitting for 4 years). I have already converted to a 929 triple/K5 GSXR forks, a 600RR swing arm, and machined the rims to accept larger 25mm 600RR axles. The motor has been powder coated and I'm currently building a subframe to work with a K6 GSXR tail. I have my turbo so as soon as I finish the tail I'll start building a stainless turbo header. More and more I'm leaning towards a carbon fiber naked/streetfighter look (plan to wrap the tank in carbon and might copy the tail in carbon). So, just "selling the bike and buying a new" is NOT the "simple solution."

If it's a project bike in that sort of sense...you might as well just give it all a go and it if doesn't work, look for your solution. I sort of thought that was why people build custom bikes like you are doing.

You should have explained all that the first time around. How all the information regarding forks/rear suspension/tail is helping out I have no idea so here is :icon_bunny1:.

Your best best would be to look it up in the service manual or maybe ask around in the F4 forums since they are more likely to know. Regardless, if you're going to run a turbo, go with a pump that you know for sure is going to flow enough fuel since you have to get one anyway. If you know what you're doing, it shouldn't be a problem.

What are you doing for fuel management BTW? Some kind of standalone or just F4i stuff with PC?