i have an '05 SV. The motor is bone stock with the usual suspension changes. it ran perfectly three weeks ago. i trailered it home, put it in the garage up on the stands. i changed the front and rear sprockets. i get to the track last weekend (Nelson Ledges) and it won't run. sitting in the paddock up on the stands it started and idled perfectly. it rained in the morning, but the bike never got wet. went out for a praactice session and it was "missing" coming out of the pits. i wasn't on it hard b/c i was checking out the track conditions. when i hit the backstretch it would cut out at high rpms in 3rd gear. it would sputter intermittently but it got progressively worse as i shifted up into higher gears. by the time i hit the kink in the backstretch, it had nothing. i coasted down the backstretch and pulled off onto the access road and pushed it behind the tire wall. it had electical power b/c all the warning lights were on. it started up but wouldn't rev past 8k rpm without cutting out. i held the throttle steady at 8k but it would drop to 5k then start running and hop back up to 8k again. it owuld bounce betwen 5 and 8k when i held the throttle constant at 8k. when the practice session was over, i tried to ride it back around to the paddock and it died on me as i pulled out onto the track. i took the ride of shame back to my paddock. i get back to the paddock and checked all the electrical connections, kill switch, kickstand switch, battery connections, etc. nothing out of the ordinary. i thought maybe water in the gas (longshot). it idled and revved perfectly in the paddock. it never missed again. Went out for my race. gridded at the back in case i bogged off the line. it bogged off the line and continued to run erratically. every time i would put a load on the motor, especially in third or higher gear and really opened the throttle it would cut out. i'm not talking a loss of power (like a compression leak) but it owuld die like it had no fuel or spark. i ran 2 laps and pulled off before the leaders could get back around to me. i'm at a loss. the computer has no errors. it is clean. as it sits, it acts like it did in the paddock. starts and revs perfectly. i checked the plugs and they are worn a bit but not too bad. i've ordered new ones anyway. i am going to drain the tank and put fresh gas from another can. again it ran great three weeks ago. i changed sprockets and chain and now it is acting up.
I only have experience with 1st gen SV's, and my overall mechanical diagnostic ability is probably a tick above the average motorcyclist, so take this for what it's worth. When i had symptoms like yours, all signs pointed to a coil issue. Check the 12v leads that attach to the coil. Mine were loose. I simply had to crimp the little spade plug a bit and the problem went away. Is it one cylinder or both? Spark plug condition? Plug wires? Other than that, i got nothin'
my bike did the exact thing you're describing last year, i thought it was fuel, then i thought it was coils, etc....it ended up being a bad cell in the battery. changed that on the spot, and it never did it again. i've heard of it on several SV's. try that.
Ahhhh.. the dreaded PC. Disconnect it and run the bike stock. See what happens. Good idea on the battery. That's something i never would've thought. All seem simple enough to test at home.
On the first Gen SV's the drain hole from the front plug would get clogged and cause it to stop firing the front cylinder. There is a small hole that needs to get cleaned out. I am not sure if that is also an issue on the 2nd Gens.
i had a similar problem with a buddy's bike last season. it was a 1st gen, but there are some good suggestions and the ultimate solution in this thread. http://forums.13x.com/showthread.php?t=142779&page=2
That same thing happened to me at Summit a couple weeks ago. Unplugged my PC and it ran fine. So that means the PC made it one weekend and took a shitter on me. Quickest 300 bucks I've blown through since this one night in Okinawa when me and..... Oh never mind.
Well, our team bike is acting up like this now. '07 SV650, sat all winter in my slightly heated garage, installed a new exhaust and dropped it at our dyno guy's shop. He called back asking what did we do to this thing? He fired it up, let it warm up a bit and was able to make a run on the dyno. When he tried to make a second run, it would start cutting out. The tach would act up on the bike but not on the dyno. When the bike acts up, the tach on the bike would read about half of the dyno tach. He's tried connecting to both front and rear coils for the dyno tach pick up and both act the same. We've tried swapping tanks thinking it might be a fuel pump issue at first and removed the PC with no change. So I dropped off a left side cover with a crank pick up to try it out. At least the full system got us about 6 HP! Too bad it won't run for more than 10 minutes.
Well, it turned out to be something simple. The plug for the crank position sensor wasn't plugged in all the way. He plugged it in correctly, and it's running fine.
