Arctic Chat : Arctic Cat Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
I have a 2004 440 sno pro with a 2003 f7 engine in it. I have tried just about everything i can think of. (Checked fuel pressure, cleaned injectors, replaced ecu, replaced power valves and put the cables to spec, swapped out power valve servo, removed smart valves in tank and replaced with inline fuel filter, swapped secondary clutch, and im sure there's more im forgetting). The sled starts right up first or second pull and runs great at idle and low speeds. When i get going it falls on its face. I have had it run well but only a couple times very intermittently.
Seems like i am down to reeds (not easy to get to with the sled being a modded 440 sno pro) and stator. My next hypothesis is that the injector coil or fuel pump coil is going bad/ a bad connection.
Any other suggestions would be greatly appreciated. Its not my main sled but i would like to get it running correctly. 2 seasons of this and lots of troubleshooting.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
Thanks for your reply. I have already disconnected the TSS. Just got a new stator in, will try that next.
 

·
Registered
Joined
·
1,367 Posts
I would get a multi meter start to Ohm things out. I don't know how everything is put in the sno pro chassis. I would say a sensor. But you would have a check engine light on if it is a sensor if everything is hooked up right. When a engine is a transplant who knows what they did as far as the electrical hook ups.
I see you said you thinking reeds. Reeds usually affects down low the sled will flood out. They open up more throttle you give. Best way to know if reeds are out is fuel all over in the air box. Fuel will spray out on the compression stroke instead of sealing. Pushing the fuel back into the carb/throttle body throat. You get flooding out extra fuel sucks back in through your carbs or throttle body on the intake stroke. Really doesn't hurt to look at the reeds anyways. See if they lay flat and seal. Or no chips or cracks in the pedals. I highly doubt that is your issue.
Since you been through the TSS. I would think the stator not putting out enough voltage. Fuel pump could or fuel pressure regulator going bad. Throw a gauge on the line going into the fuel rail. Should have around 42 PSI. Fuel pump could be getting weak.
The other thing drain the fuel out pull the fuel pick ups. They are called smart valves. You could have water in the tank. Water wont go through the screen gas will. When water gets on the screen they suck shut. Not allowing water to get in the fuel system. Pull them out make sure the spring pushes out. Might have to pull the fuel pump out totally through the filler neck. If they are stuck there as been water. Could be letting just enough fuel in to idle but suck shut once you give it throttle. Water gets in the fuel from condensation. Constant heating and cooling water will get in the fuel tank. A long with gas station tanks may have it.
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #5 ·
So there is no speedo on the sled so i can't tell if im running any codes. Maybe I'll pick up a used one. As far as fuel pressure i did install an inline pressure gauge and pressure checks out. I did also pull out the smart valves and took the screens completely out and still no luck. Do you see any problem with completely removing the screens? I have installed an inline filter as a substitute. At this point with all this info i am leaning towards the stator injector coil. Will have to pull it and ohm it out when i replace it with the new one. Hoping that fixes the problem. Thanks for your reply and sharing your method of testing reeds, great info.
 

·
Registered
Joined
·
1,367 Posts
Did you look at your primary clutch? The spring isn't broke in it? I have seen that it will bog on load. Idle fine but you go to move the sled will bog out. Spring will look sort of fine until you really take good look at it. Could be as simple as a broken primary spring.
I look at it this way. If factory put those smart valves in there. Must be a reason. Its to keep the engine from sucking water. That is why a lot of carb sleds have water traps. Water in your fuel is a sure fast way to burn the sled down. Its EFI design of a water tap. That is up to you.
 
1 - 6 of 6 Posts
Top