I have a 1994 mtn cat 580 and while running it it just died and won't start again. i have replaced the plugs and confirmed that there is a spark and that the fuel pump is working. also I took out the plugs and pulled the cord and put my finger over the pistons and felt compresion. Any ideas. thanks

Any chance you've got water/moisture in the fuel tank?

Perhaps dribble a small amount of fuel into the cylinders, reinstall the plugs and see if it will fire. That way you can decide if diagnosing the fuel system is in order.

Yeah that makes sence so I drained the tank and put new fuel in. same problem. I removed the sparkplugs and put a flame to the cylinder and one of them shot a flame like its soposed to and the other one just sat there and burned like a carasene burner. weird I thought so i pulled the handle a few times and repeted the process. same thing. I removed the head and found no problems. any sugestions, thanks

UPADATE.....

i took it to a guy who specializes in cats and he sais the computer unit is bad. i dont believe him since you can here the fuel pump pumping fuel and there is fuel flowing into the intake. I still have spark and fuel. any ideas..

your basic motor take fuel, fire, and air to run (with compression) I make the assumption you have air, your down to fuel and fire. When you put your finger over the plug hole and pulled the cord, you said you felt compression, did you get fuel mist on your finger?? Is fuel making it to the motor?? You may have spark, but good spark?? Is the spark blue or yellow? Timing issues??

Yes fuel is making it to the motor. and if the plugs are in they do get wet after a few polls. if I'm not geting enough spark would that mean it is as simple as the coil. I can't remember the color of the spark but i don't think it was blue.

Have you cleaned the carbs? Did you open the fuel shut off? The carbs should be disassembled and cleaned as part of pre-season maintenance. These sleds do not have a computer, so that can't be the problem, but the stator could be the problem, or the CDI. Confirm your compression with a compression gauge and determine if you have a problem piston/cylinder.

it is fuel injected. when i turn on the key i can hear the fuel pump turn on and it does squirt gas out if i remove the intake fuel line

You may be looking for specs on the coil and stator,,, could be your problem. Before you go replacing either, I would be checking your ground at the stator and coil or coils to see if that could be your problem.

What and were is the stator

I used to have a 1994 700 mountain cat with the battery EFI, and experienced the same problem you are having. Went round and round and kept coming back to the EFI computer. Finally, tracked the problem to a little black wire that came out of the computer and went behind it grounding it to the sled frame. This ground wire was broken inside the insulation so you couldn't really tell it was broken. May not be your problem, but your Cat expert could be right about it being the EFI computer.

Even if you are hearing the fuel pump going, the injectors are controlled by the computer. I do not believe the stator is your problem. If you are getting a strong spark, it seems unlikely the stator could be keeping you from starting

but if the computer controls the injectors but is possible defective :blush: why am I getting fuel in the cylinders

it is fuel injected. when i turn on the key i can hear the fuel pump turn on and it does squirt gas out if i remove the intake fuel line[/b]

D'Oh! I looked on Brown's and only saw the EXT 580 Mtn Cat. Today I looked again, and sure enough, just below is the EXT EFI Mtn Cat. I swear that wasn't there yesterday.

The stator is the electrical coils, for ignition and lighting. It is located behind the magneto, which is behind the recoil starter. If you are thinking that the spark might be weak, then pull the caps off the plug wires, trim the end of the wire and screw the cap back on. Over time and when removing the spark plugs frequently the connection between cap and wire can loosen and lead to poor sparking. Do all the cheap and easy thins first, before throwing money at replacement parts in hope of finding the problem.

DOH....forgot to mention. the plugs and wires are new

I remember hearing of fuse problems with those sleds,,,, I dont remember what the problem was, and the fuel pump is the only fuse I know of in that sled for sure,,, but it might be wise to look for some fuses for anything blown,,,,

you also said its and efi,,, does it have a battery or is it batteryless???? If you have a battery, you may have a weak battery,,,,

Good catch puree. On these old battery type EFI machines they are extremely sensitive to battery condition. It is the start of a new season, so it is a great time to install a new battery. The old battery could test fine, but the computer may not like it, so using a new battery is always the first thing to try on the old EFIès. There are many people who replace the battery every year just to avoid odd issues that can crop up. Try a brand new battery and see if that helps.

I finally got around to working on the sled today and it almost is starting. i have a good battery and the spark is strong. I'm almost thinking it is firing at the wrong time ie timing. how can this be corrected if it is a timing issue

I think it is a timing issue i can ge ###### to almost start. like it turns over once then i just get a bit of smoke out of the exhaust how do i set the timing?

the battery is new

I think it is a timing issue i can ge ###### to almost start. like it turns over once then i just get a bit of smoke out of the exhaust how do i set the timing?[/b]

The timing is triggered off of the magneto, which is keyed onto the crankshaft, so they don't go out of time unless something was put together wrong.

I took out the injectors today and cleaned them. with them out of the motor i pulled the rope and they had a great spray to them. still won't start though

Just because the battery is new, that doesnt mean it is good. I would still use a meter and test it. It will take you 2 minutes,,,, and then you can rule it out.

checked out the battary its ok. even put in another battery i had in a working sled. still no go

finally got around to buying a psi gage. checked both cylinders, got 110 on both

anyone know what 2 long and 2 short blinks on the computer light means???

i fixed that problem and now everything on the computer is normal. still won't start though. the battery light stays on unless i hook up a charger and set it to 50 amps. The battery is brand new

is it turning over?? is it getting fuel?? is it getting good spark. Figure it takes fuel, fire, air, and compression to run. You say you have compression and you should have air,,, your back down to fuel and fire.

is it turning over?? is it getting fuel?? is it getting good spark. Figure it takes fuel, fire, air, and compression to run. You say you have compression and you should have air,,, your back down to fuel and fire.[/b]
just a suggestion, how many miles are on the engine? had snowmobiles with 100 psi and wouldn't run, after pulling the jugs found the sides of pistons to be scored , causing loss of compression. pull the jugs look at the pistons and redo the top end, 2 stroke needs compression.

Good catch puree. On these old battery type EFI machines they are extremely sensitive to battery condition. It is the start of a new season, so it is a great time to install a new battery. The old battery could test fine, but the computer may not like it, so using a new battery is always the first thing to try on the old EFIès. There are many people who replace the battery every year just to avoid odd issues that can crop up. Try a brand new battery and see if that helps.[/b]

BINGO!!
IF MY 580 PANTERA HAS A BAD OR DISCONNECTED BATTERY=SHE'S NOT RUNNING.

no scoring on the pistons but I did notice that the crank case was filled with fuel

I had one of those sleds, and the steering shaft rubbed through the wiring harness. You might look there.

all the wiring is good. i check that a while back....still seems like its getting two much fuel. when i took off the exhaust manifold it was full of gass