Pictures and videos of my fuel injected 1978 XS1100

[Snow]

So in addition to needing an electric pump and regulator, I'll also need a return line to the tank?

I have a standard, so the tank has two petcocks... would it be prudent to hook the fuel pump inlet to one, like the left petcock and hook the pump return line to the other (right petcock) and set both petcocks or just the right to prime?

[Hobbit]

return

First, as far as I know (I no expert on all fuel pump systems by any means.) most electic fuel pumps need to return fuel back to the tank after the pressure regulator.

As far as using the prime setting for a return port....interesting idea. As long as you could pick up enough fuel for the pump to run it wouldn't matter how the fuel returned. I like that idea, but you would probably want to pick up the fuel from both sides of the tank.

[TheDjost]

There is also the flow rate through the petcock to check. Granted the pump will pull the fuel through, I would think the best (and simplest)solution for the fuel return is a simple tee fitting between the fuel pump and the fuel tank. That way, the flow through the petcock is limited to what the engine consumes. also, if you hit the kill switch, and the fuel pump stays on while the petcocks close due to loss of vacuum, you won't burst or pop off a fuel line(or fry the pump).

-Justin

[Hobbit]

That would work, but with fuel injection there is no need for the fuel to be shut off. When the injectors lose power and the fuel pump is off the fuel flow would be stop. No other fuel shut off required.

[TheDjost]

Well, even a small leak can fe fed by GRAVITY. As long as the tank is mounted higher than the engine, there is a possibility for a leak. And I'm not talking about those pesky float valves, fuel lines can crack, come loose... even the slightest weep can be dangerous if the bike is parked in a shed. The petcocks can turn off, they are already there, and they are automatic, so why not use them. They certanly can't hurt.

Think safe, when designing things.

-Justin

[Hobbit]

I agree. They would also be helpful when removing the tank for any other reason.
The fuel lines themselves will be stronger due to the higher fuel pressures on the high side.

[mainlylinux]

I've thought about this too, and another thing to consider will be fuel pressure buildup caused by the relatively restrictive petcock. hopefully if I feed from one petcock I can return in the other; I also thought about returning the fuel via a vent. Do any XS tanks have a vent feature?

Dan

[Bill__Woods]

WOW, I am blown away with the megasquirt F/I on the xs11. Good work Dan!
A few points...

....Dodge trucks use a returnless fuel system, you may want to look into that for ideas.
....I am considering building my own megasquit F/I controller for my streetbike powered Quad project!
....I would still rather have a Mikuni Carb problem,then a F/I problem, if broken down on the side of the road 200 miles from home on a 20+ year old bike.

I work on Fuel Injection for a living (ASE L1 tech), So if I can be of any help Dan - Just let me know.

PS, I have been drawing up some ideas on adapting 1996 GM DIS coils & module from a 2.2 chevy cavalier. Anyone up to testing it on thier bike?

[Bill]

mainlylinux wrote:

...hopefully if I feed from one petcock I can return in the other; I also thought about returning the fuel via a vent. Do any XS tanks have a vent feature?

• The XS11 has two petcocks because of the tank design. It has two low points and can't deliver all the fuel from either one. Suzuki managed to design similar tanks, but with one low point and one petcock. Go figure!
• The gas caps are vented. Plugged cap vents are one of those nasty problems to find when you've been riding steadily. The bike stops, you can't find the problem, and then it goes away on its own.

[TopCatGr58]

First of all, fascinating discussion!!

Second, for a possible return sight, the fuel gauge plate on the underside of the tank bolts in!! You could probably drill a hole and mount a fitting on this plate so you wouldn't have to damage the petcocks or other part of the tank. The gas caps are vented, but they are little pinhole vents, nothing you can connect a return fuel line to!!

Third, Bill, I thought most of these GM or other brands of cars use a crankshaft pickup/sensor type device for the distributorless ignitions?? It seems like it would still be easier to port a system made for another brand of bike onto ours, via adapting the Pickup mounts and such!? Just thankful both my carbs and CDI are still working!! Have fun you guys!
T.C.

[Snow]

After much thought, and a few headaches...I've come up with another idea to bounce off you guys

What about the stock GSXR600-1000 in-tank fuel pump? It is designed to be returnlineless, since it is already in tank. It's got a built in regulator that just releases directly back into the tank. There are plenty of them on ebay now.

The only problem is that the XS11 tank would have to be modified to mount the pump, which frightens me greatly.

[Hobbit]

pump

Could it be mounted on the removable plate that TC mentioned?
If so, then the stock tank would remain stock!
The most difficult part would be getting it to pick up the fuel from both sides of the tank. Perhaps just running a fuel line from one petcock hole to the other so that the fuel could balance?

[Snow]

I don't know how large that plate that already exists is, but I think the hole needed for the gixxer pump is a tad larger - it looks to be about just larger than the size of a throttle body.

I'd like to get ahold of one just to see if it might work, but can't afford to waste the money now if it doesn't.

If I had a spare tank, this might work out a little easier.

[Snow]

Oh no, the gears in my head started turning again. I remebered reading about the BGT (Big Gas Tank) made by Dave Hansen some time ago, so I pulled the page back up to take a look. It seems to me that it wouldn't be that difficult to actually custom fabricate a new gas tank specifically designed for an XS11 running fuel injection, utilizing an in-tank pump.

Certainly it must be easier to build a tank from scratch using fiberglass than it would be to modify an existing XS11 tank... or if not easier, then at least better? One benefit to fabricating a tank is that you could eliminate the need for petcocks completely.

Here's Dave's article: Big Gas Tank

[mainlylinux]

Hey pete, I got the throttle cable from motion pro. It fits great! I'll be getting the fuel pump after the holidays (read: when money isn't so tight).

More and more guys running megasquirt on their bikes!

Dan