viper motor locked solid

I do not know for sure but my hunch is that it's because the Viper's have ALOT of midrange timing. Holding them in the midrange too much is probably causing excessive heat and leading to detonation. 2 stroke motors are sensitive to heat and detonation.
 
Hard to say what happen then,if jetting AND wash was checked? then
bad fuel could be the culprit,just because the pump said premium doesn't
mean is was good stuff with no water..

post pics of the piston..
 
what i have concluded and gathered thru all of this is

1. vipers you have to RIDE them no cruising down the trail.

2. i would bump the needle up one notch on cylinder 2

3. I talked to SRXSPEC and he said to use srx lower gasket under the jugs on a viper, for some reason the port opening is bigger for the coolant passage. from the way it sounds with my sled is the #2 cylinder got to hot and cooked it self. sorry IMO viper is just not a womens sled :bash:
 
Everyone take a deep breath and step away from the motor.
Am I seeing things and could those pistons be intalled backwards? Do I see the ends of the rings? I can't tell but is that the intake hole on the piston facing the exhaust direction?
 
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Spring snow in the Hills pulls HARD, you need a lot of fuel to keep things cooled off. On a warm day with soft wet snow my egt's will run ATLEAST 100 degrees hotter in the midrange vs. a 15 degree day in powder. Crusing for miles on the needles up hills on the trails, most people dont know how close they are to a meltdown. Your jetting might be perfect on a flat section at elevation. Now check the plugs and wash on a half mile uphill section in some wet snow.....you might poop.
 
Get a rear cooler on her,that might have help this issue,heat causes
detonation so the cooler you can have the motor the better..

and what cacsrx1 said too...
 
Just curious fasttoys17........how many miles are on the Viper?

BTW, torque the clutch on at 80ft. lbs.......then loosen up again and re-torque to 43 ft. lbs. That's Yamaha's spec on the Viper primary.
 
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fasttoys17 said:
I talked to SRXSPEC and he said to use srx lower gasket under the jugs on a viper, for some reason the port opening is bigger for the coolant passage.
Click to expand...

I dont know if your getting the 2 gaskets mixed around but the coolant passages on a SRX base gasket are smaller slowing the coolant down. Which causes the coolant to take more heat along with it. Coolant passages are larger on a Viper base gasket.
 
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journeyman said:
Just curious fasttoys17........how many miles are on the Viper?

BTW, torque the clutch on at 80ft. lbs.......then loosen up again and re-torque to 43 ft. lbs. That's Yamaha's spec on the Viper primary.
Click to expand...


2200 miles and thanks for the heads up on the torque spec
 
ExpertXViper said:
I dont know if your getting the 2 gaskets mixed around but the coolant passages on a SRX base gasket are smaller slowing the coolant down. Which causes the coolant to take more heat along with it. Coolant passages are larger on a Viper base gasket.
Click to expand...

ill have to double check, i was told to use SRX gaskets
 
fasttoys17 said:
ill have to double check, i was told to use SRX gaskets
Click to expand...

As you should, I was just letting you know that you had your info mixed around with the coolant passage size from a Viper(Larger) and SRX(Smaller) and the reason why Spec told you to do so.....I have one installed on my stock Viper right now, put it on when I was thinking of running pipes but went back to stock cause I like riding alot more than tuning the clutchs and jetting.
 
SRX Coolant Passages:
PTO: .787" x .358"
MID: .591" x .358"
MAG: .591" x .358"

Viper Coolant Passages:
PTO: 1.259" x .358"
MID: .432" x .358"
MAG: .591" x .358"

The SRX base gasket evens out the coolant flow and will keep the middle & mag cylinders cooler as it does not allow all the coolant to take the easiest path (which is the PTO cylinder on the Viper base gasket).
 

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Srxspec said:
SRX Coolant Passages:
PTO: .787" x .358"
MID: .591" x .358"
MAG: .591" x .358"

Viper Coolant Passages:
PTO: 1.259" x .358"
MID: .432" x .358"
MAG: .591" x .358"

The SRX base gasket evens out the coolant flow and will keep the middle & mag cylinders cooler as it does not allow all the coolant to take the easiest path (which is the PTO cylinder on the Viper base gasket).
Click to expand...

Question Why did Yamaha change these gaskets? Was the PTO Cylinder overheating ?
 
Stevie Ray said:
Hey just to let you know this same thing happened to me and it was an engine bearing in the middle right side. There's only one way to find out for sure though......Tear it down....Good Luck
Click to expand...



took it apart today BAM we have a winner cyl 2 bearing
 
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