Sled on side-flooded

[ReX]

Guys, I think the reason quads, bikes, lawnmowers, etc, have fuel shutoffs is because they use gravity feed to the carbs (no fuel pump). The fuel pumps used in most snow machines have a check valve that will not allow the tank to drain into the crank.

The check valves allow fuel to flow into the carbs. There is one at each side of the pump mechanism.

In other words, if the fuel level is high enough and there isn't an air lock in the line the carbs will be gravity fed - at least enough to flood the motor if the needle and seats leak.

 

[nhrxrider]

Exactly. T-rex, try removing a fuel pump. You can blow through from the tank to the carb side with your mouth, its so easy! Its the OTHER direction you can't blow through. If you have more than 1/2 tank of fuel, you end up with the same type of gravity feed system bikes, lawn mowers, etc. use, so by your reasoning, you agree with us that there should be shutoffs. I don't have any yet, but I hardly ever trailer, and you can bet that before I do I'll have some installed! I had to haul my sled Sunday and Monday in my pickup, and I made sure the tank was almost empty both times.

Jim

 

[PACMAN]

So if you keep your tank with less than half of a tank, it shoudn't be a problem, ?

 

[nhrxrider]

Correct...but how often can you really make sure your tank is half empty? I try to keep mine full, which makes it very inconvenient for trailering.

Jim

 

[Blue Me]

I think that since Yooper has been so fortunate to have no problems he probably poured a gallon of gas in the carbs to have a problem so he could chat it up!! Just messin with ya bud!! I wondered about that after we talked and think that maybe there could've been some type of uneven fuel flow. I don't know how or if but could that do it if it was tipped to one side and the fuel in the lines rushed into one or two of the carbs moreso than the others? That was really the only thing I could think of. That was strange. Did you change plugs since then? Ya KNow PLUGS MAKE A HUGE DIFFERENCE!!! HAHAHAHAHA

 

[nhrxrider]

I've had my sled on its side many, many times, for suspension adjustments, when I was installing my Cat skid, changing carbides, etc. and never had a problem starting it, even without shutoffs. I just hold the throttle open while cranking and it starts right up after a couple cranks. It takes a half second or so to clean out, and runs fine. I never have to change my plugs, and am only on my second set at 5500 miles (I changed the first set around 4000 miles, just as preventitive maintenance). I don't know why he would have such problems, unless he doesn't know how to clean out the carbs with the throttle while cranking.

Jim

 

[impalapower]

Had it on its side tonight, took a bit longer to start, had the throttle wide open.

 

[smokeless1]

Twice, I went up two times as well as trailered around here with out the shut offs and never had an issue. I have been up two times since installing them and it is just plain flooded out. Have to change plugs and everything. However I leave them in the on position on the ride home, and again it starts right up. Has me baffled.

Sounds like a bad connection to the hose. Air in hose will caust problems.

Re connect them. Fuel shut-offs will NEVER cause hard start issues but a bad valve will and a bad connection could allow air into the fuel line which also would create your problems.

 

[smokeless1]

If you turn them over, or on the side, You just grab the throttle and hold it wide open. Crank it and it will unflood, like every other carb machine in the world.

 

[smokeless1]

For the fellow who wants to put his fingers in a flooded carborator, and hold it open while his buddy cranks. Please give me your address and age and appropriate information, so that when you go to toast and your unrecognizable we will know where to send your ashes. Machine can and probably will burp and this will shoot flames out of there someday. You will hardly feel a thing tho if you survive the incident. Gas flash fires very quickly and doesn't leave much residue.

 

[nhrxrider]

For what its worth, we were wrenching on an RX today and had to have it on its side for well over an hour...I think it was more like 2, but I was a bit cold and wasn't paying attention to my watch. After dropping it back down and opening the throttle all the way it started in about 2 or 3 seconds of cranking and ran fine. Same results last night when I was working on my rear suspension and greasing everything and had it on the side for over an hour.

Jim

 

[T-ReX1]

nhrxrider: I agree it is very easy to pressurize the gas tank and force gas through the gas pump, but if the gas tank vents are correct there is never any pressure in your tank. I have rejetted many Yamaha 2-strokes and when you let the gas lines go from the carbs the tank never drains (even with a full tank). The only gas you get is what is in the gas line. This is because of the check valve in the fuel pump. I'm not saying that shut off valves are not worth installing, just that you should not need them.

 

[Sodes]

You're all nuts; I love it!

I have had a lot of fun reading the crap that comes across this board. Some of the info is great and some, well is crazy. The fuel shut off issue is one of those. There is no way a fuel shut off valve (with the proper ID) can effect the starting performace of a snowmobile after installation. I have ruined a sled vacation with hydrolock and learned to install them on every sled I own. I have an O5' Vector 05' RX-1 and and a V-Max; not a problem. Go too Dennis Kirk for a terrific, lightweight in-line shut off. Keep up the crazy talk. I love the commentary especially from the Fat/Lazy Bastard (Archie Bunker of sled boards).

Sodes

 

[nhrxrider]

T-Rex, while you had the fuel lines off changing jets, did you simulate trialering? Put a straw in a McD's soft drink cup half full of Coke. Nothing comes out, right? Now shake that cup up and down and see what happens. Once the fuel in the tank gets sloshing around, it puts quite a bit of pressure into the lines. Thats what happens to a sled in a trailer. Sled trailers ride VERY rough.

Jim