What would cause this engine damage???

BC_mtn_rider · Mar 3, 2016

13 Pro 2400 miles. Stock with Hps can.
Cracked Crank & hole in top centre of Piston above it. Sled was running excellent then RPM's died pulling a hill then limped it out on 1/4 power. This doesn't look like the typical piston problem. Please help fellas!

Hardass · Mar 3, 2016

that is a case of detination big time

Blk88GT · Mar 3, 2016

x2!!!

COP-OUT · Mar 3, 2016

What octane fuel were you using

BC_mtn_rider · Mar 3, 2016

COP-OUT said:
What octane fuel were you using

94 no ethanol Chevron only.

LoudHandle · Mar 3, 2016

I'd be finding a different gas station. Or at least checking for water and cutting it with AVgas or race gas, if that is the only station in town.

smokindave · Mar 3, 2016

http://www.pure-gas.org/index.jsp?stateprov=BC

This site lists all gas stations in Canada and US that has pure gas,no ethanol.
I have read a few stories on Chevron getting ethanol mixed in 94 by accident more than once in the last couple of years.

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diamonddave · Mar 3, 2016

We stopped using 94 octane in BC and went to 91 octane because it was reported to be highly oxygenated and the 91 was not.

After situations like this...

BC_mtn_rider · Mar 3, 2016

Ya that's 2 recent Poo's I've blown up now. Regardless of what caused it....its still disappointing. Shouldn't cost you an

Reg2view · Mar 4, 2016

Deto sensor must have been on break. That kind of damage is a downer. Good luck.

BC_mtn_rider · Mar 4, 2016

Anyone have a good crank for sale!!! Lol.

geo · Mar 4, 2016

The pics of that one BMR are worth printing and hanging on the shop wall.

As mentioned before, don't know how "DET7" didn't stop this many times (first thing to fix before you run it again), but I also godda say that HPS can must be pretty loud.

BC_mtn_rider · Mar 4, 2016

Yes, I'll be keeping my piston as reminder of why I should never buy a Polaris product again.
Starts to get old when it's the 3rd time. Pretty sure the E-tech won't let me down.

Snowmow · Mar 4, 2016

BC_mtn_rider said:
Yes, I'll be keeping my piston as reminder of why I should never buy a Polaris product again.
Starts to get old when it's the 3rd time. Pretty sure the E-tech won't let me down.

Keep your Pistons as a reminder of what fuel to NOT run.

Pretty amazing it made it over 2000 miles on that fuel.

Not to sound like an azz but do you know the signs and sounds of a motor that's detonating? Appears to have been ran awhile while detonating......

LoudHandle · Mar 4, 2016

BC_mtn_rider said:
Yes, I'll be keeping my piston as reminder of why I should never buy a Polaris product again.
Starts to get old when it's the 3rd time. Pretty sure the E-tech won't let me down.

If you run that same fuel in the E-tech you'll have the same results. Of course the current (pre-850) E-tech's rods are weaker so they may go before the crank. But either way It will cost you pistons and a crank at a minimum, if you ignore the signs of Detonation.

BC_mtn_rider · Mar 5, 2016

Snowmow said:
Keep your Pistons as a reminder of what fuel to NOT run.

Pretty amazing it made it over 2000 miles on that fuel.

Not to sound like an azz but do you know the signs and sounds of a motor that's detonating? Appears to have been ran awhile while detonating......

Really hey? What fuel should I be running because every sledder in my region has been using this chevron 94 for years with no issues. I'm all ears on why I should switch fuels stations or grade. My partners E-tech has 5500 miles & its all he puts in his sled??? This DET has nothing to do with the fuel. The mag side piston was in perfect condition.
As far as how the sled sounded...it ran as strong as it ever has & sounded like it always has since new. The day before was in 3ft of fluff all day & was awesome. The 2nd day we were still in the pow in the morning then it blew on our way back.

eddy · Mar 5, 2016

Deto

Ethanol is 113 octane, so easy to see why they cheat.
Impressive the crank and rod bearings did not fail sooner.
Solution: More and Better fuel, check ignition advance (retard slightly), check compression to make sure its not to high for some reason, may want to run the stock silencer (and airbox) as well. The eroded piston means it saw over 1300 degrees F for an extended time with a high shock load to break the crank.

That motor was designed to run 300 hours before a major overhaul with 92 octane and everything stock, including the can, using proper oil. Something caused a failure that is in your control.

sledheadd · Mar 5, 2016

Seeing as the mag side piston is fine could a dirty or faulty injector cause something like this? I have not seen a piston that bad in a long time.

LoudHandle · Mar 5, 2016

Another possibility is the crank out of phase. Would make sense the mag side survived and the PTO did not. Do any clutch work lately? Blow any belts? Etc.

bailer · Mar 6, 2016

LoudHandle said:
Another possibility is the crank out of phase. Would make sense the mag side survived and the PTO did not. Do any clutch work lately? Blow any belts? Etc.

I should understand this....but nope, please explain.
I hate not figuring this out lol.

What would cause this engine damage???

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