View Full Version : Electric Fuel Pump

tri dee
01-11-2008, 12:32 PM
to cut a long story short... bought my Zee without an engine or pump. I've installed the Xt 600 engine & have also fitted a Cbr 600 fuel pump to get fuel to the carb. I'm starting to think this pump might be to powerfull & possibly push fuel through the float & into the barrell - my question is - how does the original Z fuel pump work, is it mechanical or electrical or vacuum(what operates the vacuum)?

With the Cbr pump do you think running a return fuel circuit back to the tank & Tee'ing of this circuit to the carb(a bit like a car system) stop fuel being pushed through the float? any help appreciated :confused:

01-11-2008, 01:07 PM
the fuel pump works with a pipe connected to the cylinder and works off crankshaft pressure, it feeds the carb but there is a t piece in the pipe to return any unneeded fuel to the tank.

tri dee
01-11-2008, 01:27 PM
many thanx, can't tell you how much that has helped me out. do you know where it returns on the tank, is it on the top or side & which attachment? - cheers

01-11-2008, 02:06 PM
the speed, and the fuel pressure, of the electric pump can be reduced by putting a resistor in the power leads to the pump.

Auto systems DO NOT just use a tee to return fuel, they have pressure regulators that set the inlet pressure, then send the excess back to the tank. A simple tee wont work.

Be careful screwing around with things you dont understand, especially when they can get you set on fire.

tri dee
01-11-2008, 02:35 PM
err I do understand what i'm doing, just trying to firstly understand how the Zee system works before modding - this is experimetal hence posted in the Lair :rolleyes:

01-11-2008, 03:12 PM
I've found these on this site but i dont know if they'll help you, If no one has helped you by tomorrow i'll be able to look at my bike and tell you exactly which pipe goes where.

tri dee
01-14-2008, 03:36 PM
just won an original pump off good 'ole Ebay so i'll hook it up to one of the carb inlet stubbs & see if that works before rigging up the leccy pump - still need help working out which pipe connects where..

01-14-2008, 03:43 PM
As you look at the pictures i posted above, the one at the bottom of the fuel pump goes to the breather on the cylinder/barrel. the other one with the t piece on goes to the carb and the other pipe that should be on the t piece but is not shown in the pic is the return to the tank, ( i cant remember exactly where the return goes on the tank) but as you look at the tank from the back of the bike there is 2 outlet pipes on the right hand side, the bottom one is for reserve and the one just above it is for normal. I've tried to help from memory but if this doesn't help you I could go and get some pics.

01-14-2008, 03:53 PM
Ive just been out to check but my camara is acting up. what I wrote above is ok and the return from the t-piece goes to the pipe at the top near the filler cap (its a bigger diameter pipe than the other fuel pipes) as you look at the fuel tap on the pump, the 2 fuel pipes going into the tap are both the feed pipes from the tank and the bottom pipe needs to go to the bottom one on the tank and the top one on the tap goes to the other one on the tank thats higher up, I hope this helps you out. If it doesn't let me know what else you need.

tri dee
01-14-2008, 04:54 PM
that was a spot on description bud, I wasn't sure if the larger dia pipe was the return or breather. I'm presuming the breather is the smaller pipe on the very rear of the tank? getting closer to firing her up now :Bounce

01-14-2008, 05:03 PM
have you got any more pics

tri dee
01-14-2008, 05:09 PM
last ones are here http://www.3wheelerworldforums.com/showthread.php?t=78033

i'd take some more but it looks just the same only covered in wires & pipes :lol: