03' Viper new motor rebuild after the sled runs for about an hour it will cut out but not die. When motor was out I checked wire harness under motor and even put it in wire molding, no signs of cuts. New Yamaha stater with rebuild. The motor feels like a coil is dropping out could this be the problem? How do I test for this? I have tested the following with no success:
1. Unplugged harness to hood gauges (motor runs problem still there)
2. Unplugged throttle safety switch.
3. Ran motor and moved as many wires as I could touch and not make it fail.
4. Check connections from stator, carb, head, others
5. Cleaned Spark plug boots and inspected wires put on electrolis (spell)
6. Spent 6 hours going through wires at stator location and at hood connections.
7. New plugs
This got worse at the end of the day would drop out 15 times, would come to a stop (motor does not die) rev up motor and go again. Happens at low speeds and high speeds. My rebuild was almost a success, Help Please.
Dealer will take back stator and ohm out and inspect so I ordered a new one. This is the only electrical item I changed on the sled at rebuild. How do I OHM out my stator? What are the spec's?
1. Unplugged harness to hood gauges (motor runs problem still there)
2. Unplugged throttle safety switch.
3. Ran motor and moved as many wires as I could touch and not make it fail.
4. Check connections from stator, carb, head, others
5. Cleaned Spark plug boots and inspected wires put on electrolis (spell)
6. Spent 6 hours going through wires at stator location and at hood connections.
7. New plugs
This got worse at the end of the day would drop out 15 times, would come to a stop (motor does not die) rev up motor and go again. Happens at low speeds and high speeds. My rebuild was almost a success, Help Please.
Dealer will take back stator and ohm out and inspect so I ordered a new one. This is the only electrical item I changed on the sled at rebuild. How do I OHM out my stator? What are the spec's?
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Anyone got ideas?
Just got off the phone with a Yamaha senior level tech. He recommended checking two places for wire damage. First up from where the stator connects, know rub location. Second, wire harness connector where it goes from hood to engine. Mine has pipes so a great deal of heat in this location. Will update in a few hours, got to get this one fixed for a ride to the flat tops this week.
make sure those spark plug cap are good ...
maybe ask to mr viper he know alots about viper
how can I tell if the boots are bad? Have not found any bad wires yet and have pulled apart lots of wires.... I am not having fun..
viperking
Active member
check the plug cap for corrosion like stated above. my viper would run good for a while and then would drop a cylinder and i would change my plugs and everything but it wouldn't help. it would run good for a while and then just lose a cylinder. scrape the insides of the caps with a pocket knife and put a little grease on the tips of the plugs and see if it still does it
4 + hours later now almost midnight and I found one chafed wire and the ones going to the hood melted together. Not touching copper but I am going to extend and cut out the bad section. Will re-route away from the tipple pipes so that will never happen again. Thanks for the plug recommendation I will clean caps and used the electric stuff on the plugs. Lastly I moved my wire harness from the pipes side of the tipples and ran the harness up by the clutch area. Don't worry Viper readers I protected the wires very WELL. No more heat problems with that section of wire. It started in 2 pulls. Thanks again for the assistance on this one.
I updated the first entry on this thread with more detail. I am going to pull the new stator off the motor and replace with a second new one. Yamaha will only warranty the stator if they can bench determine that the other one is defective. I am going to the Yamaha show in Denver tonight so will talk to the H.Q. men on site. I would like to ohm out my own stator if anyone knows the spec's and how to do?
Check the plug caps with an ohmeter (about 5K).
Then check all the rest of the electric components in an isolated fashion. Do this directly after a failure.
Specs are in the service manual and in the Tech Updates manuals.
Do a search, as this has been posted before. I have posted some of it myself.
Then check all the rest of the electric components in an isolated fashion. Do this directly after a failure.
Specs are in the service manual and in the Tech Updates manuals.
Do a search, as this has been posted before. I have posted some of it myself.
trail viper
New member
keep us posted with the updates. my 02 never did run right this year, eventually dropped #2and #3 cylinders. could not make them fire even with spark in those holes. new stator, cdi, flywheel, relays, moving coils and plug caps. tore motor down and it looks like new; ring end gap still within spec @ 8000 miles.