If you test for spark this way ^^ make FNGing sure your not going to blow a bunch of raw gas out of the plug holes that is puddled in the crankcase. Spark from the grounded plug turns the engine into instant flamethrower, very bad mon!!
One cylinder loading up on fuel 02 800 RMK
- Thread starter Damon8
- Start date
Plug the PTO side plug wire onto the MAG side plug. MAG plug wire to PTO plug. See if the issue follows that side of the coil. Or if a buddy has a similar sled you can swap his on and see if it's fixed. Most the Liberty twin motors had the same coil..
You're kidding me right? That's like changing the plug wires all around on your car, and see what happens. Changing to another coil, I can agree with. I even have one for sale for $40. Just PM me.
R
The coil fires both cylinders at the same time. It does not sense which cylinder is at compression. It is rare, but I have had one side of a coil fail.
I also have seen one side of a coil fail.
D
We did take the coil off the 700 & tried it, same problem. Also switched plug wires around and the problem did not follow to the other side so I think the coil is fine. tested the olms on the stator and all that is good as well. still scratching our heads on it..
R
Did you check/switch the reeds yet?
Yes, Switched reeds around and same problem. I just pulled the jug off to look at the piston/sleeve and everything looks fine. Pretty much out of ideas. One thing that does come to mind is that I did put silicon over the cracks in the airbox to seal it up tight (Cracks where they put the two halves of the airbox together). Would this somehow freakishly cause one cylinder to load up? We're out of ideas and do not know what to do. Never ran into something like this before.
So far we have:
Switched to a different set of carbs
Switched reeds around
Switched plugs
Switched plug wires
Checked the ohms on the stator
Switched fuel pump
Put new Float/seat/needle in bad side
Checked exhaust valves
Switched coil out with another sled
Switched jets around
Checked needles
We've had the carbs apart several times
Checked the Y pipe and exhaust for mice nests or anything else that could possibly get in there
Can It be something stupid like the fuel shutoff? The silicon in the airbox? Guessing not as this would most likely cause the other cylinder to act up but.. We're out of ideas. I'm willing to send some $$ to the person who figures this disaster out.
Thanks!
So far we have:
Switched to a different set of carbs
Switched reeds around
Switched plugs
Switched plug wires
Checked the ohms on the stator
Switched fuel pump
Put new Float/seat/needle in bad side
Checked exhaust valves
Switched coil out with another sled
Switched jets around
Checked needles
We've had the carbs apart several times
Checked the Y pipe and exhaust for mice nests or anything else that could possibly get in there
Can It be something stupid like the fuel shutoff? The silicon in the airbox? Guessing not as this would most likely cause the other cylinder to act up but.. We're out of ideas. I'm willing to send some $$ to the person who figures this disaster out.
Thanks!
I'd love to put my hands on this thing. I'm stumped as well.
D
compression was 145 on the pto and 150 on the mag.
R
Have you always owned this sled? Ever had the motor apart?
D
Yes, I've owned it for 4 years. Put new pistons in it a couple years back and now I have the one cylinder off.
Oh I don't kid when a guy is trying to trouble shoot a sled when there's good snow to be had. The coil has just two wires entering (and it's not grounded through it's mount), it can only receive one signal--fire, and there is no "switch" inside that directs electricity to each plug on every other fire. It's much simpler than a car with a distributor or coil packs. New coils are only $40 anyway: http://www.mfgsupply.com/01-143-69.html
To the OP, that's a tough one! I'm running low on ideas. I'd probably pull the jugs if it were me. Maybe a cracked skirt or something weird, that you would want to catch ASAP.
Edit: you posted that you have a cylinder off as I wrote this out. How's it look?
R
Crank out of phase? Did you swap carb boots side to side? Did you swap valves side to side?
N
Check your fuel delivery to carbs. Remove the fuel shutoff valve. Feed fuel into carbs by using another fuel contanier, bypassing the sleds fuel tank.
rdr99 might have hit it. Crank out of phase? Had any violent belt explosions lately?
You can try changing out the cylinder head O-rings to new Polaris high temperature O-rings. One side may be leaking coolant into the cylinder, which will screw it up fast.
L
Check the needle, the clip held down by the allen screw may be loose which will let the needle ride up out of position when you go anything over idle flooding the motor. Then shut it down the needle drops to where it belongs and it all starts over again when you rev it up.
R
He tried a different set of carbs, no difference. I'm thinking it is something internal.
