Fuel pressure related 2004 RX1

[Rusty1-ton]

I recently had someone tell me that the RX1 has a very bad fuel system problem, one the fuel pump sits higher then the tank so you definitely can't run it less then a 1/4 tank of gas or you'll lose all pressure and never get it running again, idk what he was talking about, but is this true and is there a way to fix the problem if there actually is a problem

 

[Redbeard]

The fuel pump(s) on the RX1 are pulse type, triggered by vacuum from the intake. They suck and blow like all traditional pulse pumps. When the engine is running, they're pumping, assuming all internal check valves, vacuum lines and fuel supply lines are working correctly.

They will lose prime when sitting for an extended period, but their high placement will not cause them to quit pumping when the gas tank level is at 1/4.

Even a tunnel mounted fuel pump would have to suck fuel up and out from the top of the fuel tank.

 

[Rusty1-ton]

The fuel pump(s) on the RX1 are pulse type, triggered by vacuum from the intake. They suck and blow like all traditional pulse pumps. When the engine is running, they're pumping, assuming all internal check valves and vacuum lines are working correctly.

They will lose prime when sitting for an extended period, but their high placement will not cause them to quit pumping when the gas tank level is at 1/4 or below.

Even a tunnel mounted fuel pump would have to suck fuel up and out from the top of the fuel tank.

I would say your informant is mis-informed.

Yeah that's kinda what I was thinking but yeah he did mention after seat a long time it will lose prime and that I'll never get it running again until I hook up a vacuum pressure type cap the hooks to your air compressor but that sounds a bit ridiculous, unless you have a problem somewhere else in the fuel system

 

[Redbeard]

Yeah that's kinda what I was thinking but yeah he did mention after seat a long time it will lose prime and that I'll never get it running again until I hook up a vacuum pressure type cap the hooks to your air compressor but that sounds a bit ridiculous, unless you have a problem somewhere else in the fuel system

When they lose prime, it's basically the same as running them out of fuel. It takes forever to pump fuel from the gas tank to the carbs by cranking the engine alone.

There's a handful of ways to re-prime the fuel. Yes, you can pinch the fuel tank vent and pressurize the gas tank with compressed air, but I prefer to pour gas straight into the fuel line with a mini funnel (fuel supply line between fuel pump and carb). The fuel pumps are very accessible on the Rx1. Open the hood and they're right there on the left side of upper delta box frame.

When I pull my Vector and Warrior out of storage each fall, I pour fuel into the lines, as described above, and they light instantly.

Long story short...saying you can't run them below 1/4 tank of fuel simply is not true.

 

[Rusty1-ton]

When they lose prime, it's basically the same as running them out of fuel. It takes forever to pump fuel from the gas tank to the carbs by cranking the engine alone.

There's a handful of ways to re-prime the fuel. Yes, you can pinch the fuel tank vent and pressurize the gas tank with compressed air, but I personally find it easier to pour gas straight into the fuel line with a mini funnel (fuel supply line between fuel pump and carb). The fuel pumps are very accessible on the Rx1. Open the hood and they're right there on the left side of upper delta box frame.

When I pull my Vector and Warrior out of storage each fall, I pour fuel into the lines, as described above, and they light instantly.

Long story short...saying you can't run them below 1/4 tank of fuel simply is not true.

Oh alright that helps me out a lot thanks at least I know what to expect I Appreciate that info

 

[RobX-1]

When I would disassemble the carbs to clean throttle bodies and jets and such in my RX-1, it would result in the bowls being emptied upon reassembly. How I would prime the carbs was to take a piece of tubing (e.g. fuel line tubing) and place it partially into the fuel tank opening and then used duct tape to seal as good as you can around the tubing and the rim of the fuel tank. Blowing into the tubing, it would pressurize the tank and force fuel to the carbs. This always resulted in the RX-1 staring within 3-4 cranks and you don't have to worry about draining your battery.

 

[Rusty1-ton]

Nice I'll keep that in mind I just thought the guy that was telling me this was a bit crazy, I mean why wouldn't you be able to run something less then 1/4 tank or it would lose prime that sounds nuts so I had to ask

 

[maim]

part of why we start our sleds every month in the off season. never had to pressurise the tank on our rx sleds. a lazy way is to hook the boost leads to a car battery and crank until it fires. as long as carbs are good, it will fire off.

 

[Fortress]

You guys should just pop the top off air box and squirt gas into carbs, it primes right away.

 

[RobX-1]

The only reason I have to prime the carbs on the RX-1 is because I take the carbs off each year, disassemble, clean, reassemble, and sync. I also drain/siphon the gas from the tank during the off season so that after all the work of cleaning the carbs, only fresh fuel is introduced. I'm sure there are other ways to prime the carbs but what has worked for me is using a tube and some duct tape and blowing into the tank. Once the carbs are primed and the sled is running, the carbs are ready to be sync'd.

 

[Fortress]

I have 2 2004 rx1s,don't have time for doing that, but I do run them every 6 weeks or so to keep the fuel moving,they are parked in a really hot sea can all summer

 

[smallheadz]

After I clean or drain carbs I just remove vent line (down at the footwell) , blow in it (to pressurize tank a little), pinch off the line, cranks 5 seconds max and fires