***UPDATE 2:***
sideshowBob said:
I have almost completed the offseason overhaul on my 2002 SRX[just waiting for a couple parts]
-fuel tank, lines, and carbs completely dry
-I installed the new Fuel Pump[no hole in bottom]
-elliminated fuel loop from tank to pump
-poured 5 gallons of premix in fuel tank
Intitially I left the carbs off to see how fuel flowed from pump:
-fuel was definately gravity feeding to fuel pump
-no fuel passing thru the pump when sitting static
I then pulled the engine over to watch for fuel pump action:
-no fuel flowed from fuel lines!
-checked pulse line - OK
-Checked fuel supply to pump - OK
-pulled engine over with + without plugs - NO FUEL FLOW FROM LINES!
-reinstalled old fuel pump - SAME THING-NO FUEL!
-put a fuel pressure guage on pulse line - when pulled over 2 - 4 psi
-reinstalled new pump
-installed carbs but left fuel lines off
I then decided to do just a short start on it as the pipes + power valves are not installed yet but everything else is completed:
- put a couple of ounces of premix done the spark plug holes
-gave it two pulls and it started right away
- it pumped fuel like mad out of the fuel lines until it quit
-pulled it over a few times and again - NO FUEL FLOW!
Conclusion:
On my SRX the pumps I have require more pulse action then the recoil can provide to flow fuel.
If the pump + lines + carbs are dry, no amount of hand cranking is going to fill those float bowls up! Fuel down the cylinders is going to be required to start it + provide enough pulse to run the pump.
Questions:
-My engine is trail ported[has been for a couple years], has this worsened an issue with crankcase pulse?
-I have after market reeds with spacers, again has the crankcase volume increase caused some issues?
-Is this an issue that only shows up on ported Engines or do the stock SRXs have this condition as well.
When I installed an SRX fuel pump on our Piped/Ported SX700 it developed a starting issue after a long sit as well, our other identical SX with its stock pump is much better
-Is this purely a fuel pump Issue?
I have seen on a previous post that someone installed a primer bulb in the fuel line...maybe I will do that as well, that would alleviate this issue on my sled.
***UPDATED INFO:***
Today I drained all the fuel from my sled again[2002 SRX]:
- checked the fuel filter - OK
Reinstalled stock fuel loop:
-had to add @7 imperial gallons[@28 litres/@9 us gallons] in my sled before fuel would gravity flow from fuel loop.
Installed 1999 SX 700 fuel pump[no vent hole in bottom, fittings all the same, + looks identical externally to SRX pump except it does not have rubber X-over line]:
-pulled sled over with recoil - instant fuel flow from all fuel lines!
-reinstalled New SRX fuel pump...still no fuel when pulled over!
Conclusion:
-either I am getting dud SRX fuel pumps or they require a fairly strong pulse to operate
-I have installed the 99 SX700 fuel pump and will be using it[it operated fine on our SX when it had a Bender 800 BB kit with TMX 38s]
-reinstalled stock fuel loop and when the sled has sat for a long period I will make sure I have more then 7 gallons in the tank so fuel can gravity feed!
Additional Info:
I hooked up a primer bulb from a boat tank to one of my hand held SRX fuel pumps to see how fuel would flow thru the pump:
-when bulb was squeezed fuel came out the oil line fitting only.
-if I held my thumb over the oil line fitting and squeezed the bulb, fairly hard, fuel would VERY reluctantly flow from the fuel line fittings
Hope this info helps...do with it what you may!! LOL!
Things that make you go HMMMMM ! Keeps it interesting!