SeX Viper
Member
I was riding WOT a couple weeks ago in the UP and my viper simply shut off. I rolled to a stop and was able to restart but the engine was making all kinds of clanking so i shut it down. The center piston is melted on the top and the rod bearing on the crank is gone. When I took everything apart I noticed the exhaust donut between the manifold and pipe was in very bad shape and even completely gone in one spot.
My question is do you think this was enough to cause the burn down? I have ridden over 1000 miles this season and 160 the day before and 100 the day of so I do not believe it was a carb problem but I will take them a part as a precaution. I am running a completely stock sled with Mr Viper recommended raised needles and fuel screw setting. Always run non ethanol premium. I do have a rear cooler and there was plenty of snow, the temp light did not come on at all. The motor does have 11,000 miles on it, I did the top end around 7,000 miles.
My question is do you think this was enough to cause the burn down? I have ridden over 1000 miles this season and 160 the day before and 100 the day of so I do not believe it was a carb problem but I will take them a part as a precaution. I am running a completely stock sled with Mr Viper recommended raised needles and fuel screw setting. Always run non ethanol premium. I do have a rear cooler and there was plenty of snow, the temp light did not come on at all. The motor does have 11,000 miles on it, I did the top end around 7,000 miles.
yes, likely the donut being bad did it, its a straight shot to the center cylinder from the manifold donut. Its when the exhaust return pulse is brought back into the cylinder, it stuffs the cylinder for more efficient packing of the cylinder, kinda like a mini supercharger if you will but pulls the air from a leaking donut into the cylinder,adding more air with less fuel = lean=heat. The whole process usually takes awhile to do the damage.
It first adds heat, then comes detonation which is actually what pounds the rod bearings out of them, then once all that shrapnel gets going around, it damages piston top and edges and that material ruins the rings, or the piston crown will get burnt back exposing the ring to the flame front, gets orange from the heat and bends/melts... and its all over.
It first adds heat, then comes detonation which is actually what pounds the rod bearings out of them, then once all that shrapnel gets going around, it damages piston top and edges and that material ruins the rings, or the piston crown will get burnt back exposing the ring to the flame front, gets orange from the heat and bends/melts... and its all over.
Lil' Mtndreamer
New member
I had a 600, my exhaust donut was leaking so i guess it was bad too... same thing happend to me.
SeX Viper
Member
Thanks, that is what I figured but wanted some reassurance. I dropped the crank off today and the guy said parts are hard to come by for them now so we will see if it can be fixed or not. I already bought a new sled but hate to see this one go even if I do only ride it once in awhile.