power valves

Ropin_tom · Jan 22, 2016

hey guys no sure if anyone else has had this problem, but my sled lost the pto cyl last weekend, i started ripping into see if i could find the problem. when i took the head off there was obvious damage tot he piston and power valve. after ripping it all apart it appears like the small aluminum stopper on the pto power valave had actually worn down causing the power valve to creep into the cylinder and they made contact.

2014 pro rmk
2500kms

jay_boom · Jan 22, 2016

Just had the same issue but mag side on my 2013.

volcano buster · Jan 23, 2016

I sent in a cylinder this fall to get repaired on my 600. When I was digging around it seemed that the pv shoulder would wear out the bottom of the hole in the cylinder and do the same thing. Is this Polaris' fix to that constant slamming? If so, is this a common wear item that should be replaced at a given interval? First I have seen of them but I don't own an 800.

Ropin_tom · Jan 23, 2016

i havent read anyother topics on this so it seems slighly rare, well rare enough that my polaris dealer cant even find the part in their system or maintance manual

any one have a part number for these?

diamonddave · Jan 27, 2016

Very interesting....have you found a part number for this?

Reg2view · Jan 28, 2016

Quite the little scheme by Polaris to sell more top end engine parts, pistons, cylinders, PVs, etc.

2500kms ain't that much - wonder why we haven't seen more of this. Gotta open up some PV assemblies now.

RHODESIE · Jan 28, 2016

pv

looks like a big bore with spacers to keep the guilatine from contacting the piston.

sledneck_03 · Feb 25, 2016

I just cleaned mine and no spacers. Must be an add on from the big bore kit.

gunnerthesnowman · Feb 25, 2016

RHODESIE said:
looks like a big bore with spacers to keep the guilatine from contacting the piston.

sledneck_03 said:
I just cleaned mine and no spacers. Must be an add on from the big bore kit.

If its a big bore and done right , the guilatine should of been cut down to match the cylinder bore .

The Bob · Feb 26, 2016

I think RK Tek uses spacers like that instead of cutting/grinding down the valve. Not positive, but I know where there is a RK Tek 858 kit for sale and it has those Iron Cross looking spacers.

My 15 doesn't have anything like that.

sledneck_03 · Feb 26, 2016

Sounds like band aids

Merlin · Feb 27, 2016

If those spacers are indeed add-ons to gain clearance for a larger piston in a big bore kit, I'd be speaking with the manufacturer. If an interval for replacement of the spacers is not specified at the time of purchase then this failure should be considered as a flaw in the design of the kit. IMO

High Voltage · Feb 27, 2016

Well does this sled have a big bore kit in it?:juggle:

DLynn · Feb 28, 2016

The exhaust valves have not changed for many years. 2015 back has used the same valves. The spacer is an add on. There are a lot of unanswered questions in this post that need to be answered before a judgment can be made. Once you MOD a motor all bets are off for motor longevity. You want more power you pay the price and take the risk of failure. Just my two cents.

gtwitch · Mar 7, 2016

Had the same issues with older CFI4 Engines and the gillotines were contacting pistons and same damages. I have a process whereby I take about .030 off the faces of the valves and have done this to all of my pro's (3) now and the 800 dragon and hopefully have no more valve to piston-interference. Hope this helps, Indy Dan can cut the valve faces for you also. I have spoken with him about this problem.

gtwitch in wyoming

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power valves

Ropin_tom

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jay_boom

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volcano buster

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Ropin_tom

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diamonddave

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Reg2view

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The Bob

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