Slingshot pump in tank

[Mike750]

Hi all I'm in the middle of my 750 project and I've bought a external pump and malp regulator , but I'm thinking now besides using that pump and getting a return welded into the tank to get a damaged tank off something newer and cut the bottom plate out and weld it into my tank , witch would have the feed and return keeping it more tidy, I no it's been done but has anyone done it to a slingshot tank and any idea what newer Suzuki pump I could use in the k bike that could fit ? Thanks for any help thought it would be a nice tidy job

[Mike750]

Anyone out there gave this ago for there turbo application??

[Slabby11]

I think one of the problems is getting the in-tank regulator a boost reference.

[davecara]

It'll work if you still put a return in the tank. I've got the bottom of a K4 tank welded into my slingshot tank for when I was doing an N/A EFI conversion, Its all gone wrong since then.....

[Gixer1460]

49 minutes ago, davecara said:

It'll work if you still put a return in the tank. 

Why - Please explain? As the whole point of an in-tank pump is it doesn't need a return?

[vizman]

The return from the regulator?

[Gixer1460]

11 minutes ago, vizman said:

The return from the regulator?

The regulators are generally built into the in-tank pump assembly!

Edited April 23, 2020 by Gixer1460

[Arttu]

9 hours ago, Gixer1460 said:

The regulators are generally built into the in-tank pump assembly!

But for turbo applications you preferably need a boost referenced regulator. Regulators used on in-tank pump assemblies don't have that option. In theory you could use suitable regulator and still keep it in the tank but then you would need to route a boost reference hose inside the tank.

Or you could keep using a non boost referenced regulator and pressurize the tank by boost pressure. That should work too. Until the tank explodes

[vizman]

3 hours ago, Arttu said:

But for turbo applications you preferably need a boost referenced regulator. Regulators used on in-tank pump assemblies don't have that option. 

That’s what I thought but wasn’t 100%

[Gixer1460]

Yes I understand the boost reference thing but just adding an external regulator wouldn't achieve anything! You'll have to gut the pump of its integrated regulator and re-integrate the filters etc. They are complex pieces of packaging. If you are cutting a hole in the tank anyway i'd just use a std external pump but fitted internally, flow & returns and wiring pass through - sealing is the biggest problem though.

[vizman]

Again that’s what I thought.....I couldn’t get my head around fitting a non turbo applicable fuel pump into a tank that would be used on a turbo bike, just seems to be creating more work for yourself...

[ElBlandito]

I believe Luke tried this with a few different pumps on his turbo bandit, but towards the end it looks like he stuck with an external walbro. He may be a good resource for the challenges, but I'm not entirely certain he still owns the bike (as it was listed for sale some months back). Have a read through as its a great reference for Turbo/EFI.

https://oldskoolsuzuki.info/forums/topic/3123-turbo-bandit/

 

[davecara]

A walbro 255 pump fits into a L0/L1 750 pump housing and has the same mounting bolt pattern as a K4 1000.

Less plumbing = less pipe work full of fuel exposed to the heat of an oil boiler, its neater and takes up less room. 

[Mike750]

Thanks for the replies guys il do a bit more research on it but looks like I'll be making a lot more work for myself trying to fit the pump in tank , cheers 

[Mike750]

Been watching a few videos of these pumps and I think it's possible with some work to remove the regulator and pipe it straight to my external regulator , or like you said fit walbro pump that just has the pipe fittings rather than a o ring fitting, thanks again il keep ye posted 

[Mike750]

Roughly just looking at the pictures of most of those pumps is the sump part that that sticks out of the tank about two inches, doesn't look like I've got a lot of room between the bottom of my tank and the carbs bout a inch and half to be safe, if anyone has one and gets a chance to measure thanks 

[no class]

the pump housings are from a K6 1000 and K9 1000 .... both are identical bolt patern . the K6 has a 2” recessed bowl .

 

Edited April 24, 2020 by no class

[Mike750]

thanks for that il have a good look at it tomorrow see what can be done cheers for taking the time 

[badger]

On 4/24/2020 at 1:46 PM, davecara said:

A walbro 255 pump fits into a L0/L1 750 pump housing and has the same mounting bolt pattern as a K4 1000.

Less plumbing = less pipe work full of fuel exposed to the heat of an oil boiler, its neater and takes up less room. 

What I did on mine too. Mostly for the lack of room i have. External fuel reg still

[JK1]

I also cut the tank bottom from newer gsxr. I replaced the pump with  Wallbro, and made a "dummy" regulator with a  lathe. Then I used a external reulator and added a  return line . 

http://koti.mbnet.fi/jk11/kuvat/turbo-s/IMG_7931.jpg