Fuel pump??

Just curious I took off my fuel line at the carb when I'm cranking it shud fuel be pumping out of the line?? 
My rhino died on the trail after riding a long time has spark but when cranking no fuel out the line the crappy part was getting towed back by a XP!!!!

Also does anyone know what kinda fuel pressure that pump is suppose to put out??

Djbison wrote:

Just curious I took off my fuel line at the carb when I'm cranking it shud fuel be pumping out of the line?? 
My rhino died on the trail after riding a long time has spark but when cranking no fuel out the line the crappy part was getting towed back by a XP!!!!

You should inspect the fuel system as a whole. I'm assuming that you have a stock pump. The pump is a strictly mechanical thing that uses pressure pulses from the intake manifold to operate a diaphragm which pushes and pulls fuel within the body of the pump. There are check valves at the inlet and the outlet of the pump that let the fuel only pass in one direction. So, when the diaphragm is pulling fuel it enters the inlet (while fuel at the outlet cannot get back in) and fills the innards of the pump. When the diaphragm pushes fuel, it cannot go back out of the inlet, hence it has to go out of the outlet check valve.

The very first thing to do is to replace the fuel filter and try starting it. Filters are notorious for plugging up and putting you out of action. It will take a lot of cranking to prime the pump even if everything is working well.

Then, if that did not do the trick, check the condition of the small hose from the intake manifold to the pump. It should, of course, be tightly connected at both ends. There should be no cracks or hardness in the hose itself. Push and pull on the hose to check the connections. Just to be sure that there are no engine valve problems, unhook the pump end of the hose and crank the engine. You should feel strong vacuum pulses with your finger over the open end of the hose while cranking.

If that seems OK, carefully check the hoses and fittings on the intake side (fuel tank to pump). Check for overly stiff or cracked hoses. Check the fittings and dip tube in the tank for cracks or leaks. The tank fitting is notorious for getting cracked if the seat is pushed into it while installing the seat. Carefully check the hose attachments to their fittings, the tiniest leak of air will prevent enough suction to be developed by the pump to actually lift the fuel to the level of the pump.

Good luck, and get back to this thread should these things not be your problem.

Everything Steve said, If it's the pump I have a stocker that I bought last season. Has less than 100km on it. I put on a high output pump. If you want the stocker cheap PM me.

Hey thekrust are u in bc Canada??

I will never have a stocker again on mine. I had nothing but problems. The clear fuel line that come in the high volume kits are awesome. My fuel pick up cracked and I new right away that I didn't have any fuel. Steve got most of it covered. Make sure the vent line coming out of the tank is not sucking against the roll bar or cut it off at an angle. We just put a billet fuel pickup on from axia alloys because it was cracked. Hope you get it fixed!

Yep, close to Osoyoos

Yeh I'm thinking of getting the high flow pump it has been taking a few cranks to start lately

Does anyone no what kinda pressure it is that goes to the carb??

I think its like 1.5 to 4 psi.

Djbison wrote:

Does anyone no what kinda pressure it is that goes to the carb??

Not very much at all. I would venture to say less than 1/2 PSI at the inlet fitting to the carburetor.

The carb on the Rhino is a motorcycle carb at heart. The float valve is designed to work being gravity fed from a motorcycle gas tank just above it, certainly within a foot of it. That amounts to very little actual pressure.

The fuel system in a Rhino has a crude pressure regulator of sorts. The fuel line from the pump has a Y fitting in it before the fuel reaches the carburetor. The hose branching off of that Y returns fuel to the tank. That return line should be aimed upward from the Y fitting such that the top of its arc is above the carb inlet by a fair amount. This increases the pressure at the carb to something similar to the gravity fed tank that I mentioned before. If the return line is aimed downward the pressure can be below what it takes to feed the carb and there will be starvation issues at speed.

One thing that is very helpful in troubleshooting is to re-plumb the hoses with fuel resistant transparent tubing. That way, you can actually see the fuel flowing and determine where the fuel problem lies. I have transparent lines and I temporarily rigged up a very long return line that went up and over the roll cage. This makes for a very handy low pressure gauge in that the fuel rises to a certain level and does not have enough pressure to make it all the way up over the loop. This makes for a pressure measurement of 'inches of gasoline' similar to the 'inches of water' or 'inches of mercury' (used for barometric pressure, air pressure being around 29 inHg or 14.7 psi). These 'inches of ....' differ due to the different densities of the liquids. All said and done, I was measuring around 18" of gasoline in my setup. That works out to be 0.5 PSI.

Actually "head Pressure" is .434 PSI per foot of elevation at sea level.

Sorry SteveS....Had to quote you something technical for once.......lol (Probably will never happen again!)

4x4ff wrote:

Actually "head Pressure" is .434 PSI per foot of elevation at sea level.

Sorry SteveS....Had to quote you something technical for once.......lol (Probably will never happen again!)

Ahhh, someone who knows what pressure head is! The number you mention is for water, much more useful for dams and water tanks of course. However, to make it applicable here, the density of gasoline is only 74% that of water so that has to be factored in as well. I must add that one has to be a bit careful with gasoline manometers, as not to set it on fire (especially when it is over your head).

Thanks.

Touche my friend......touche

Steve
(The other Steve)

4x4ff wrote:

Touche my friend......touche

Steve
(The other Steve)

We had both best wear our fencing helmets if we keep doing this, eh?

Lol......I have no objection to bowing to the master.

4x4ff wrote:

Lol......I have no objection to bowing to the master.

Oh, this 'master' DOES fall upon his face periodically!