Hi Guys,
My brothers 2002 Viper ER has been bulletproof until our first ride of the season this year. It wont rev past 7500 rpm now. Here is a list of what we did to it this year before the first ride...
New track and bearings installed
carbs cleaned
power valves cleaned - no pull throughs
It was also put away properly (greased, fogged and stabil)
The sled starts and idles great. Clutch is engaging at 4000rpm or around that. Stock clutching, pipe and everything else.
Compression test resulted in the following 110-125-125 so it should be good there. Plugs looked good too.
Any idea where to start looking to fix this machine so it has balls again?
It has 15,900km's on it. Maybe time to check the reeds??? I don't know what would make it run and idle normal but not rev up???
My brothers 2002 Viper ER has been bulletproof until our first ride of the season this year. It wont rev past 7500 rpm now. Here is a list of what we did to it this year before the first ride...
New track and bearings installed
carbs cleaned
power valves cleaned - no pull throughs
It was also put away properly (greased, fogged and stabil)
The sled starts and idles great. Clutch is engaging at 4000rpm or around that. Stock clutching, pipe and everything else.
Compression test resulted in the following 110-125-125 so it should be good there. Plugs looked good too.
Any idea where to start looking to fix this machine so it has balls again?
It has 15,900km's on it. Maybe time to check the reeds??? I don't know what would make it run and idle normal but not rev up???
super1c
Super Moderator
Were clutches cleaned and how old is the belt? Might just need a good cleaning. Check you rollers and weights for wear also. Also reed cages, did you check your reeds?
My srx 700 would not rev past 7900 no matter what,found out the crank had slipped out of phase on the pto end,it was off so far that the pto and center pistons were almost at tdc at the same time, had to retime the crank and weld both centers,yamaha welded the rod pins but not the centers and they slip.
staggs65
Moderator
I know you said powervalves were cleaned and no pull throughs. are they adjusted right, servo working? clutches like Super said.
did u put the power valve on the good side
staggs65 said:I know you said powervalves were cleaned and no pull throughs. are they adjusted right, servo working? /QUOTE]
eggsactly,take off the plastic servo cover(3 screws) above sec. clutch, then turn on your key and see if the servo moves??
report back.
The belt is mint (OEM), clutches are pretty clean. Didn't check reeds yet, I wanna test what I found below first...
The servo is working perfectly when I turn the key and there are no pull throughs. The valves are adjusted properly. But...
I did notice however that the MAG side power valve was put in upside down. I haven't had a chance to put it back together yet, but could something this simple cause this much power loss and low max rpm (7500)?
The servo is working perfectly when I turn the key and there are no pull throughs. The valves are adjusted properly. But...
I did notice however that the MAG side power valve was put in upside down. I haven't had a chance to put it back together yet, but could something this simple cause this much power loss and low max rpm (7500)?
That is possible, but I would definitely pull your reeds. My guess is you might have a reed petal missing. Something similar happened to me once and Vipers are known for reed issues.
bluebullet
New member
Does it rev up on the jack stand? Check belt, clutching.... One other thing to check is mice nest on pipe or can. I had a baffle drop ( Can) in my wife's 500 that would kill the sled above 5,000 RPMs but below it would run like a champ on the ground. On the jack stand ( No load) it would ramp all the way to 8000 rpms. Drove me crazy until one day I started without the can and ran great ( Loud) put the can back on and it would choke the motor at 5,000 rpms again! Crazy... I always I weird stuff happen to me!
Good luck, Blue
Good luck, Blue