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Discussion Starter · #1 ·
I’ve tried everything to remove the power valve. Let it warm up. I’ve used penetrating oil. I’ve put on my big boy gloves and pulled and wiggled. What do I do next? Do I pull the head and start prying from inside. I’m assuming it’s bent.
 

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If it's bent, you have a lot more problems than a stuck valve.
What do the plugs look like??
Your probably going to pull the head at least.
 

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Discussion Starter · #3 ·
If it's bent, you have a lot more problems than a stuck valve.
What do the plugs look like??
Your probably going to pull the head at least.
Plugs look good. Not burnt but dark and running rich. I’m assuming the guy I bought it off of didn’t clean the valves often. The one I got out isn’t terrible looking, but needs cleaned. Not sure if it’s bent. There could be a bur on it. I’ll know more when I pull the head. If it’s bent what other problems could I be facing?
 

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Likely bent from being overheated. The valves on the 800 are poorly cooled since the larger bore of the 800 versus the 700 caused the need to eliminate the coolant passage above the exhaust valve. With the valves being aluminum, they overheat easier and can start to deform easily.

On an 800 I've had with bent valves, I was able to take the cylinder and head off and use a dremel to VERY carefully grind away the aluminum from inside the cylinder bore until the valve to slide out. I was parting out the sled, so I didn't care about the valve, taking the cylinder off made it easier. Could probably do it with just taking the head off, but then you have to worry about metal dust getting into the piston rings and crank.

Polaris knew this was an issue, there were a few updates to the valves - first they offered stainless valves as an upgrade to withstand the heat, but then also added a titanium option because stainless was too heavy for ideal operation.
 
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