Well this is a sticky problem!! I've been working on this thing for about 2 weeks now and it will not work for me. I have had many mechanics look at it and they've all given up on it, not to mention that my father is a great certified mechanic and he just cannot figure this thing out. well this is whats wrong with it
When you crank the key, it will just rev but it wont turn over. I threw spark test lights on the 2 of the 3 spark plugs. I find out that its sparking as soon as you let go of the key. sometimes it will rev up with right timing but no go. I ripped out the cdi box and found a small red indicator bumping out of the back side of it. I just figured it was shorted and I went and bought a new one. I have the new CDI box in it, and it does the same thing. I have the exhaust off right now so the exhaust is coming straight from the cylinders. If you crank the key too long it will shoot out flames every couple backfires. Also one other thing to mention that STILL boggles me is:
When i was working on it 2 days ago, My dad noticed the dash board wasnt lighting up with the key on. and so we disconnected the dash board and the thing started right up. It was running fine that day. We even connected back up the dash and the RPM and everything was fine. We turned it off. 10-20 minutes later we try to start it back up again and no luck. 10-20 minutes after that, it starts running again! but sometimes it shuts off after 15 seconds or so. It has a brand new battery in it, a jump pack is always hooked up to it, and i still cant figure it out.
I dont have any idea what it is, im still an inexperienced mechanic (Im only 14 and im posting this for my dad), but even when I have my pops and his mechanic friends look at it; nobody has any suggestions. Lately, I havent gotten it to run for a day or 2. I have fiddled with all the coils, all the wires to it and everything. Its just an ELECTRICAL MESS. That is why im coming HERE! lol
Also, just a couple minutes ago I read that the engine harness on the exhuast side can rub through the wires causing some to touch and screw things up.
Please any suggestions would be greatly appreciated. 2002 Yamaha SxViper 700. thank you
When you crank the key, it will just rev but it wont turn over. I threw spark test lights on the 2 of the 3 spark plugs. I find out that its sparking as soon as you let go of the key. sometimes it will rev up with right timing but no go. I ripped out the cdi box and found a small red indicator bumping out of the back side of it. I just figured it was shorted and I went and bought a new one. I have the new CDI box in it, and it does the same thing. I have the exhaust off right now so the exhaust is coming straight from the cylinders. If you crank the key too long it will shoot out flames every couple backfires. Also one other thing to mention that STILL boggles me is:
When i was working on it 2 days ago, My dad noticed the dash board wasnt lighting up with the key on. and so we disconnected the dash board and the thing started right up. It was running fine that day. We even connected back up the dash and the RPM and everything was fine. We turned it off. 10-20 minutes later we try to start it back up again and no luck. 10-20 minutes after that, it starts running again! but sometimes it shuts off after 15 seconds or so. It has a brand new battery in it, a jump pack is always hooked up to it, and i still cant figure it out.
I dont have any idea what it is, im still an inexperienced mechanic (Im only 14 and im posting this for my dad), but even when I have my pops and his mechanic friends look at it; nobody has any suggestions. Lately, I havent gotten it to run for a day or 2. I have fiddled with all the coils, all the wires to it and everything. Its just an ELECTRICAL MESS. That is why im coming HERE! lol
Also, just a couple minutes ago I read that the engine harness on the exhuast side can rub through the wires causing some to touch and screw things up.
Please any suggestions would be greatly appreciated. 2002 Yamaha SxViper 700. thank you
On some vipers the main wire harnass that runs under the motor to the front corner of the hood wears through. You have to unhook it in front loosen the tabs, and pull it out the back side too check it. One simple thing to do is hook a string to it when you pull it out so you have a string to pull it back through. It sounds like it might be the key switch too. Unplug the key switch behind the dash, it is like a 3 wire conector from the key switch, then with the kill switch up or in the on posistion, try and start it with the pull rope. It will run with the switch disconnected. Let us know if any of this works. I'd start with the key switch. Maxdlx
I Agree Go To The Harness Under The Motor Mine Was Rubed Through Causing Diffrent Come And Go Issues! Good Luck But I Would Say Harness!
hey, i just pulled out all those wires going under the harness and nothing looks cut but it did look a little smashed up. So far nothing is wrong with those wires under the harness but im just curious, what are those 2 small black wires on the ignition switch. Also, could it be that the crank sensor is causing this??
Last edited:
ok now I'm really confused!! I was foolin around and I thought to myself "i'm feeling lucky right now" I turned the key to start it and the thing prounced up with no problems!! The sled sounds FIERCE. What did I do!? While it was running, I got on the back pullbar and jumped up and down on it CONSTANTLY and no interuptions? I don't believe its anything sensitive. I just about wiggled any wire within my reach EVERYTHING. What did I do? Before when it would start every 1 in 50 cranks, sometimes it would just die out after 5-15 seconds. Now right now, it is running like nothing was ever wrong with it but I still dont trust to be out on the trails and have it die mysteriously like that and not be able to crank 50 times without a jumpstart. And not to mention I wouldnt be able to have the resources I have now to fix it on the trails. It looks like Ill just have to ride it around the yard a couple times to test it out. Any other suggestions other than the wire harness?