Air in fuel system - Snowmobile Forum: Your #1 Snowmobile Forum

dhodson2004 · 02-11-2008, 08:58 PM

'79 Arctic Cat Jag 2000

Hi. I cleaned the carb, rebuilt fuel pump, and replaced all fuel lines. How do I get the air out of everything? Thanks.

**smallengineguy** · 02-11-2008, 09:00 PM

The air should purge itself after it runs for a minute or two.

dhodson2004 · 02-11-2008, 09:13 PM

I've pulled it over a lot. It isn't sucking gas into the filter. Does it possibly need to be primed?

**smallengineguy** · 02-11-2008, 09:15 PM

It could be. Can you suck a little up into the line?

dhodson2004 · 02-11-2008, 09:22 PM

I've got a small plastic bottle with a strawlike nipple on the cap. I could fill the lines, pump and filter with gas.

**smallengineguy** · 02-12-2008, 07:21 AM

I htink there is a check valve in the tank to keep the fuel in the lines. Yours may be missing?

dhodson2004 · 02-12-2008, 11:09 AM

The fuel hose in the tank has nothing on it. Since I got this sled in December, it has acted like it starves for fuel. Give it gas, and it bogs. Slowly give it gas, and it is fine. Sometimes I don't see any gas in the filter when I try to start it up.

BC_Dan · 02-12-2008, 11:24 AM

I would definitely get a check valve/filter on the hose end in the tank. If you pull the plugs and add a bit of gas into the cylinders, the engine will usually start and run long enough to help fill the fuel lines and float bowls. You may have to do it more than once. When I do that, I add some oil to the gas that I am putting into the plug holes to make sure there is lubrication.

dhodson2004 · 02-12-2008, 11:28 AM

What would the check valve/filter look like? Not sure where I would be able to get one.

**RJ Gleason** · 02-12-2008, 12:36 PM

Online microfiche:
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Arctic Cat E-Parts Catalogs -- EMPARTweb Version 5.2.2

dhodson2004 · 02-12-2008, 04:12 PM

I primed the fuel system and put some gas in the cylinders. It ran long enough to burn off what was in the cylinders. When I had primed it, I saw gas coming out of the fuel pump around each screw. Kind of hard to pump fuel if it is sucking in air. I'm going to replace the pump tonight. It is in rough shape. Someone has had it apart many times. I've got to wait till 6. That's when the used snowmobile parts guy gets in. The woman at the desk said they carry the in tank filters. I'll pick one of those up too. Am I going to have to jack it up to replace the old pump? Or will I be able to just hook the new one up for now? We've got 6-10" of snow coming tonight and I just want to get it off of my lawn for now. It is going to get burried again where it is. Thanks.

dhodson2004 · 02-12-2008, 11:08 PM

Installed the "in tank filter w/ ball check". Hooked up the new (used) fuel pump and primed the system. It ran long enough to use up the gas in the lines. That was about it. Everything is all air again.

BC_Dan · 02-13-2008, 12:04 AM

If there are holes anywhere in the system, it will suck air. You may have a hole or crack in the line inside the tank. Those are a pain to get to and are not replaced as regularly as the lines that are on the outside. Start at the fuel filter inside the tank and examine every hose and connection, there has to be a hole somewhere.

tckitt13 · 02-13-2008, 04:47 AM

Ditto BC Dan. Your system is sucking air somewhere between the fuel pump and the fuel tank. Or else the tank is empty

in which case you're gonna feel really stupid

I won't tell you how I know

dhodson2004 · 02-13-2008, 07:22 AM

Quote:

Originally Posted by tckitt13

Ditto BC Dan. Your system is sucking air somewhere between the fuel pump and the fuel tank. Or else the tank is empty

in which case you're gonna feel really stupid

I won't tell you how I know

lol. No, there is 3/4 of a tank. I had to put all that gas back in after the tank was cleaned and put back on. Haven't been able to run it yet.

dhodson2004 · 02-13-2008, 11:09 AM

Tomorrow I am going to replace the fuel hoses and get 8 clamps. I take it that the previous owner didn't think it needed them. I'll see how that goes. Today is snow blowing and roof shoveling. If this ice storm keeps up, I'll have to dig out the generator. Fun, fun...

tckitt13 · 02-13-2008, 01:09 PM

One hint with the hose clamps: Don't go too tight! Sometimes people tighten the clamps too far and that will make the lines leak too.

dhodson2004 · 02-13-2008, 01:25 PM

Seen that problem before. I was planning on getting the type that are on my snow blower. You squeeze them with pliers. I hate the typical hose clamps that are the screw type. The hose in the tank was already replaced when I had the tank off. There was some crud that got picked up and stuck in it. The hoses are pretty loose on the fittings. So maybe clamps will do it... Still going to do the other hoses to be sure.

dhodson2004 · 02-14-2008, 05:33 PM

I picked up some clamps and put them on. Put a little gas in the cylinders, and git it started. Sucked the gas out of the lines again. I heard air coming from the gas cap. It was tight. I tightened it as much as I dared to. Tried starting it again. It attempts to, but you can't get to the throttle fast enough. There are two types of fuel hoses on it. The hose from the pump to the carb is hard plastic. All other hoses are soft rubber. What type is correct?

tckitt13 · 02-14-2008, 05:49 PM

Take the fuel line off of the fuel pump that comes from the gas tank. Take the gas cap off and blow air back through the hose. You should be able to hear plenty of air bubbling in the gas tank. Hook the hose back up to the pump and try to start. If you still have problems, take a hose off from the carb and put it in a can or jar. Pull the sled over several times to see how much fuel the pump is pumping.

There is nothing majic here, either you're not getting fuel to the pump (clogged or collapsing hose) or the pump isn't pumping it to the carbs.

Good Luck