TimeBomb
New member
i believe this was a topic on here before but i can't find the thread. i've noticed lately when i race my viper from a dead stop, if i just bar it it takes off screaming like normal, normal peak rpms but then it suddenly sounds like it drops on 2 cylinders and will only hit 7,000-7500 rpms. then when i let off and get back onto the throttle it is normal again. anyone have any ideas?
yamaholic22
Active member
it was my buddies viper that you are referring. We cleaned the powervalves real good again and he rode it 600 miles this last weekend and he said it didn't bog once. Must've been a sticky valve.
yamaholic22
Active member
bypassing it did nothing. It would be revving perfect, and then just bog down about 1,000 rpm until you let off, then if you would get back on it it would be fine. The TORS will take it right down to idle.
blueblooded
Member
My mach z use to do that and it turned out to be the fuel pump.
TimeBomb
New member
i bet it has something to do with the powervalves, b/c i get the powervalve code when i start it up. engine diagnostic light flashes 7 times
yamaholic22
Active member
based on what i have seen i would say that that is the best place to start. rx1yama18 thought that his valves were fine because he had just cleaned them about 1000 miles before that, but sure enough he took them out and they were real gummed up, cleaned them, reassembled and it has been good as new for 600 miles so far.