I just got an 04 SX Viper Mtn. from a friend. It has 7k miles, but it is in great shape. It starts great, runs great, but when it gets to around 6k rpm, it starts cutting out. I posted an earlier post, he said that it was cutting out at around 4k rpm, but I took it out today and it cuts out at around 6k rpm.
The TORS is disconnected, one plug wire had a gouge, so I put on a new coil. I removed and cleaned the carbs and both jets. I removed and cleaned the power valves. The kill switch was broken and I put on a new throttle block. The throttle cable is adjusted correctly, not too tight. The choke cable is adjusted so that the choke is not partially engaged.
I took it out today and when it gets to 6k, the tach starts jumping up and down and it starts cutting out and backfires. This happens at about 35mph. I drove it for a while, cruising at around 30-35mph and slowly it started running better. Eventually I got up to about 70mph and around 8200 rpm. I stopped and shut the sled off and sat awhile, and when I started back up, it did the same thing at around 6k, but after driving for about 10 min, it would open up to around 8k, but it would still cut out a little.
Compression on all three cylinders is good. I have the air screws on the carbs at 1 3/4 turns out from lightly seated. Plugs are a nice light brown color.
Could this be the CDI or stator? Does it make sense that the problem gets better as the sled warms up? Could this be a fuel problem?
Thanks
The TORS is disconnected, one plug wire had a gouge, so I put on a new coil. I removed and cleaned the carbs and both jets. I removed and cleaned the power valves. The kill switch was broken and I put on a new throttle block. The throttle cable is adjusted correctly, not too tight. The choke cable is adjusted so that the choke is not partially engaged.
I took it out today and when it gets to 6k, the tach starts jumping up and down and it starts cutting out and backfires. This happens at about 35mph. I drove it for a while, cruising at around 30-35mph and slowly it started running better. Eventually I got up to about 70mph and around 8200 rpm. I stopped and shut the sled off and sat awhile, and when I started back up, it did the same thing at around 6k, but after driving for about 10 min, it would open up to around 8k, but it would still cut out a little.
Compression on all three cylinders is good. I have the air screws on the carbs at 1 3/4 turns out from lightly seated. Plugs are a nice light brown color.
Could this be the CDI or stator? Does it make sense that the problem gets better as the sled warms up? Could this be a fuel problem?
Thanks
Viper Treats
New member
Did you check for electrical shorts? Harness under the motor?
Skidooslayer687
Member
My buddy had a 98 srx that would do the exact same thing, run good for awhile and then run like a bag of crap, some days it would run real good, others it would be mixed and it ended up being a weak stator.... not saying this is your problem but it'd be worth checking out imo for the amount of time it takes, search for testing a stator. theres some really good writeups on how to test it... or you could pm mrviper700 and he could tell you bang on more then likely
I removed the stator to check for any obvious loose wires, etc. Everything looked good. The inside of the flywheel was dirty so I cleaned it up. Next step is to check the stator.
What is the best way to test the stator with it removed from the sled? I also Pm'd Mrviper700.
Thanks
What is the best way to test the stator with it removed from the sled? I also Pm'd Mrviper700.
Thanks
xsivhp
Active member
Do a search on here - you may be able to check the resistance, but I would think you almost need to load test it.