srx engine down

[srx4ever]

i recently sold my srx to a friend and last weekend we went on a trip. We were riding really hard trails were smooth, straight and long. After about 60 miles my friend with my old srx wouldnt run. We got it to start and i began to check spark pugs. the first plug i checked i knew it was major trouble, tip had been hit touching electrode with shiny powder all around. i asked him what fuel did he put and he put the cheap 87 octane. Anyways a few days later, i helped him open up engine to see the extent of the damage. cylinder no 1 had piston worn at exhaust side, exhaust valve was broken( im guessing ring expanded hitting valve). almost no visible damage to cylinder except a tiny bit of mashed aluminum on top of exhaust port. cylindre no 2 has no damage but top of piston has been slighty worn on exhaust side. cylindre no 3 is hopelesly damaged real deep gauging, piston is missing chunks on top exhaust side, rings are missing on exhaust side, peices of rings looks like hit top of piston and cylinder head also shows sings of metal hitting the top.

My question is this, does running 87 octane create overheating in combustion chamber resulting in damage stated above. I have always run high octane when i owned my srx for obvious reason. I didnt tell my freind about running high octane cause i thought it was common knowledge. This is his first sled.
I want to make sure the fuel was the problem before repairing.

 

[daman]

sounds like detonation/jetting problem to me, not good, should have used premium gas, always in a srx...

$$ repair ahead for somone.

you should have told him about using premium and BR9ECS plugs in a srx.

 

[Turk]

You gotta run premium in those sleds. You detonated the motor from not using fuel with enuff octane. You can get lucky occaisonely running regular. Most often then not you detonate; especially on long hi speed runs.

 

[triple]

i recently sold my srx to a friend and last weekend we went on a trip. We were riding really hard trails were smooth, straight and long. After about 60 miles my friend with my old srx wouldnt run. We got it to start and i began to check spark pugs. the first plug i checked i knew it was major trouble, tip had been hit touching electrode with shiny powder all around. i asked him what fuel did he put and he put the cheap 87 octane. Anyways a few days later, i helped him open up engine to see the extent of the damage. cylinder no 1 had piston worn at exhaust side, exhaust valve was broken( im guessing ring expanded hitting valve). almost no visible damage to cylinder except a tiny bit of mashed aluminum on top of exhaust port. cylindre no 2 has no damage but top of piston has been slighty worn on exhaust side. cylindre no 3 is hopelesly damaged real deep gauging, piston is missing chunks on top exhaust side, rings are missing on exhaust side, peices of rings looks like hit top of piston and cylinder head also shows sings of metal hitting the top.

My question is this, does running 87 octane create overheating in combustion chamber resulting in damage stated above. I have always run high octane when i owned my srx for obvious reason. I didnt tell my freind about running high octane cause i thought it was common knowledge. This is his first sled.
I want to make sure the fuel was the problem before repairing.

My guess is yeah, the cheap gas caused it to detonate on all cylinders. It seems that if you had an isolated problem, only one would burn up. The real techs will chime in, but yes, that's my final answer.