2009 D8 with a fired cyclinder

[Jeff95]

2009 D8 with one fried cylinder

2009 Dragon 800 155.Last week I fried the stater side cyclinder. The PTO side looks bran new. I have put about 400miles since the 2010 update. My air box is sealed and very clean inside. I run a air filter like Timbersleds.
My buddy has a 08 and had the same thing happen to him last year.
Why would one side get fried and other side look new?
Is this a injector problem? The dealer can not explain to me how to prevent this from happening again.

Thanks
Jeff

 

[IDPOLARIS]

Is polaris going to fix it under warenty. A Lot people are running the pc5 .

 

[Jeff95]

Yes,
But how can I prevent it from happening again?

Why only one cylinder?

Jeff

 

[towngrunt]

As stated before, PCV.

 

[skibreeze]

Yes,
But how can I prevent it from happening again?

Why only one cylinder?

Jeff

Sell it.

There is a fine line between lean and too lean. I have been thru 10 pistons in mine over a season and a half. Each time it has been one piston and yes, it does switch sides. My next step is to swain tech the pistons to give it a little more protection from seizing.

 

[Jeff95]

Thanks,

I guess I don't understand how one cylinder could look new and one be fried. I would think the computer ouputs the same for both, but that fine line between OK and fried could explain. I Guess you just richen up the map to protect cylinder and loose the HP!
It's too bad the dragon went from a great mountain machine to a slow gutless machine. All dragon owner were sold a 150hp machine and now have a 140 ish hp machine. I have spen a bit of money tring to get the RPM. I guess if you don't have the HP you don't have the HP!!


Jeff

 

[gcmci]

If you had a carbed sled and you changed or modded the intake or exhaust would you not change the jets so with efi this still needs to be done the sleds are on the edge of lean with out any mods so get a pcv which changes the jetting electronically and and brings back the hp

 

[Jeff95]

Should you get the Auto tune with the PCV?

Jeff

 

[mountainhorse]

A lot of mag side piston failures, when the PTO is good, are related to cooling.

If the bypass hole on the thermostat is plugged on a Dragon (not a standard RMK)... there is no coolant flow to that cylinder until the thermostat opens up. The PTO side bypasses through the throttle body heater lines.

This COULD be your problem.

Other than adding more intake screens like the ones from Fire N Ice or others, and sealing up the air intake... other mods are a waste of time IMO.

 

[Jeff95]

I sealed up the air box. I added a filter like Timbersleds. I have done some RPM/Track speed test with filter on and off. The filter on didn't change RPM/Track Speed. I used the same air cone that is on the hood. Maybe I should change to a larger diameter cone or filter mount? If I put a SLP air intake kit in I will need to seal up the air intake on the hood. I get a lot of dirt/dust in that area. I also would like to make a cover for just the hood lights and air vents to help prevent dust when in shop and on sled deck.

I ride 6000+ and may get the higher Compression heads. I hate to spend any more money tring to get this thing to run better!

 

[Boston Racing]

Sell it.

There is a fine line between lean and too lean. I have been thru 10 pistons in mine over a season and a half. Each time it has been one piston and yes, it does switch sides. My next step is to swain tech the pistons to give it a little more protection from seizing.

There is no way a microscopic coating on the piston will help your problem Dave. We used swain tech coating on our drag bikes and on a good running bike it will wear off. We need to figure out the cause rather than trying to find a band aid.

 

[Boston Racing]

Another thing I was thinking of is doing a leak down test on the motors having problems. Maybe a crank seal is the culprit. Maybe the turbo poped one out. On turbo banshees they have to stake them in and sometimes superglue them to keep them from popping out.

 

[08Alaska800]

Does anyone know if the pistons are on backorder for the D8's? My motor
went down 2 weeks ago and the dealer hasn't brought it in to even look at
it yet. He keeps telling me there is no reason to because the pistons are on
backorder.

 

[OnlyPolaris]

just checked my polaris sight and they are in stock.

 

[hilinerider]

A lot of mag side piston failures, when the PTO is good, are related to cooling.

If the bypass hole on the thermostat is plugged on a Dragon (not a standard RMK)... there is no coolant flow to that cylinder until the thermostat opens up. The PTO side bypasses through the throttle body heater lines.

This COULD be your problem.

Other than adding more intake screens like the ones from Fire N Ice or others, and sealing up the air intake... other mods are a waste of time IMO.

the last 4 08 d8 10 update sleds that i know blowed up was the pto cylinder and all lost a piston skirt??????????
any ideas???????
2 of em are dumpin em and goin to cat, i am stuck and worried that when the warranty runs out i will be stuck with the bill, all were stock with only venting and cans, different elevations and conditions when the went??

 

[08Alaska800]

just checked my polaris sight and they are in stock.

Thanks for checking for me.

 

[Cardiac Kid]

A lot of mag side piston failures, when the PTO is good, are related to cooling.

If the bypass hole on the thermostat is plugged on a Dragon (not a standard RMK)... there is no coolant flow to that cylinder until the thermostat opens up. The PTO side bypasses through the throttle body heater lines.

This COULD be your problem.

Other than adding more intake screens like the ones from Fire N Ice or others, and sealing up the air intake... other mods are a waste of time IMO.

This has happened on a number of sleds. I would at least pull the Thermostat and check.

 

[KAWGRN]

does drilling the hole bigger in the thermostat help???

 

[Ron]

does drilling the hole bigger in the thermostat help???

Jack at Carl's told me the same thing mid season and I drilled my thermo hole bigger, ran without one last year. It takes a little effort to stabilize the parts so that you can drill. I used a screwdriver to open it enough to get shims under it and then gripped the plate with needle nose vise grips.
I think MH's post about plugging can progress another step at least in theory. The small hole (even if it's not plugged) may not allow enough flow so a burndown could happen on the mag side! At least 1/2 the sleds I see leaving the parking lot get too little warm up time.

 

[IceCap]

Does anyone know if polaris has a updated thermostat?

You would think that if there is a coolant flow problem to the mag side of the engine that someone (Polaris) would have a fix for it??

Is there any change made in regard to coolant flow in the 2011 800 engine?