Arctic Chat

tazzij · 11-08-2006, 10:20 PM

Any help would be greatly appreciated. I will do the best to describe the problem. I have a 94 zr 700 approximately 4000 miles on the sled. Heres what it is doing. The sled will start fine but is only running on one cylinder. Sporadically it will gain power like the other cylinder is kicking firing but not often. Messing around with it in the garage I pulled one of the plug the left plug wire off while the sled was idling, and the rpms picked up, I then put that same wire back on and removed the other plug wire, the sled stalled so I know it is running on the right cylinder. The left plug is also wet when removed after letting idle. Both plugs show visible spark. Left pipe was getting filled with fuel from left cylinder. Compression is at 117 and 118 left and right cylinder respectively. Carbs have been gone through and are at stock settings. A new external coil was installed last year as thought to be part of the problem, however problem still persists. I am not sure what else it may be. Last year I was told by a local sled shop that a cracked piston skirt may could be a cause does this sound correct? I was told there was an internal coil on the stator but not sure if this would cause this problem thought i would get some input before i go replacing good parts. Any help would be greatly appreciated.
Thanks

**kev** · 11-09-2006, 09:03 AM

I know you said you went through the carbs, but what you describe sounds like it could be a stuck choke plunger. On mine the pipe would fill up with gas and there is just too much gas for in to ignite. You need three things, spark, fuel and air, and you got them. So my guess is too much fuel drowning it out.

Good luck!

SPDFREEK · 11-09-2006, 10:25 AM

Exactly what kev said. Make sure they are adjusted properly and make sure they're clean. Check the rubber seal on the bottom of the plunger as well.
Let us know.

94ZR580 · 11-09-2006, 11:23 AM

So, you have a new igniton coil, so we should assume it is making spark. Both plugs fire at the same time, so you need to swap the caps to see if the problem follows the wire. Put the MAG side plug cap on to the PTO side plug and vice versa. If the problem follows the wire, then you know it is in the cap and wire and not in the carb. If the problem does not follow the plug wire then you need to look into the carb on the offending cylinder. It could be a stuck choke like the others have said, or the inlet needle and seat, or the floats, etc. The first thing to do is to determine if the problem is spark or fuel related by swapping the plug wires side to side. The plug caps are only friction fit onto the wires, so a loose connectin there can cause problems like you have.

Jeff H · 11-09-2006, 12:19 PM

maybe check your reed on the cylinder with the wet plug too.

Auggie · 11-09-2006, 04:22 PM

I think that Jeff is on to something. I had a 700 in the shop with the same problem and it turned out to be the reed cage gasket. Part of the gasket was missing. Before you remove the cyl. though remove both spark plug caps and cut around 1/2" off of the end of the spark plug wire and check the caps resistance. Around 5000 ohms. Spray the wire ends with WD-40 and screw the caps back on.

auggie

tazzij · 11-09-2006, 04:51 PM

"Both plugs fire at the same time, so you need to swap the caps to see if the problem follows the wire. Put the MAG side plug cap on to the PTO side plug and vice versa. If the problem follows the wire, then you know it is in the cap and wire and not in the carb. If the problem does not follow the plug wire then you need to look into the carb on the offending cylinder.I swapped the plugs wires last year and the problem"

I did swap the plug wires last year and the problem remained in the left cyl. I do not think the sled has reeds, I am pretty sure it is port carburated. I will go through the carbs and take a closer look at what you guys mentioned. Any thoughts on the possible cracked piston skirt?
Thanks

Auggie · 11-09-2006, 05:01 PM

If its the 700 twin I am thinking about it has reeds and they are bolted to the bottom of the cyl.

Auggie

mopar · 11-09-2006, 07:55 PM

Yeah that engine was the same one in my '99 700 (I had a '94 also) and it is case reed inducted. The reeds are on the bottom of the cylinders.

tazzij · 11-10-2006, 12:31 PM

I guess it does have reeds then. I thought I was going crazy not seeing them at the base of the carb. Anyway I will go through the carbs first then if the problem is still there. I will pull the jugs and check out the reeds. Appreciate the help.
thanks