Cylinder down, need advice

goforbroke · Nov 29, 2011

Purchased an 09 IQ 600 last April with 3000 miles and I've had 3 trips on it and I lost compression in a cylinder. pulled off the head and this is what I see.

see attachment

I'm no engine pro and I need some help. I'm assuming burn down on one cylinder as air is entering some where. What do I look for?

I see no scoring on cylinder so am I okay to replace just Piston and rings? Should I do both pistons?

Are these SPI pistons okay to use? http://www.ebay.com/itm/Polaris-200...Parts_Accessories&vxp=mtr&hash=item2a12e01724

skibreeze · Nov 29, 2011

Did it burn down this year after sitting all summer? Could be clogged jets, torn intake, these would be the most common culprits.

goforbroke · Nov 29, 2011

It is an 09' with EFI, I believe CFI4 engine. it ran about 60 miles this past weekend before going down. Seemed to run awesome and then started to run poor and withing 5 miles felt like on one cylinder.

Vertical Asshauler · Nov 29, 2011

Would be best to do both pistons with a cylinder hone at the same time, that way its not just a patch job. I've had great luck with SPI pistons (installed on dozens of sled). They are cast and will last MUCH longer then wiesco's in this machine.

Here are somethings to check for that can cause a burn down on this machine.

Check throttle body boot for breaks, cracks and if throttle body itself is correctly attached to boot. Make sure exhaust valves are clean and that both the valves and solenoid are functioning correctly. New fuel filter and fresh fuel in tank is a must also.

Pownar · Nov 29, 2011

Vertical Asshauler said:
Would be best to do both pistons with a cylinder hone at the same time, that way its not just a patch job. I've had great luck with SPI pistons (installed on dozens of sled). They are cast and will last MUCH longer then wiesco's in this machine.

Here are somethings to check for that can cause a burn down on this machine.

Check throttle body boot for breaks, cracks and if throttle body itself is correctly attached to boot. Make sure exhaust valves are clean and that both the valves and solenoid are functioning correctly. New fuel filter and fresh fuel in tank is a must also.

Have you had some bad luck with the wiseco's?

ezra · Nov 30, 2011

if nothing jumps out at you as to why could be crank seals.had that happen on a f7 with 600mi on it.figured it out after 2nd burn down.has burnt side ran hotter for some time or never payed attention?

PaulAnd · Nov 30, 2011

Waiting for my IQ to pop so I can put a Carls 660 kit in it...

KJAssault · Nov 30, 2011

first thought is fuel filter i say this because my sled made it 452 mile on first motor do to plastic filings in the tank. it was the mag cylinder too and according to my polaris tech buddy that side goes first in a lean out situation. just put a new one on and cut the old one apart and find out start with simple stuff. as far as the rebuild depends on how much you want to spend. to me the pto cylinder looks fine and lookes like the 600 is separate jugs so pull one hone it new piston base gasket and run it. thats my 2cents good luck.

thefullmonte · Nov 30, 2011

I second that you should replace the fuel filter. SPI makes an affordable replacement now and is available from WPS. With today's fuel you just don't know. Also, it is very likely that the throttle body boots could have de laminated. I caught this on my 800.
I would not have a problem running SPI pistons either.

Vertical Asshauler · Nov 30, 2011

Pownar said:
Have you had some bad luck with the wiseco's?

Yes, I have seen far to many locating pins fall out of them and have ring turns. They are forged which makes them softer then cast. Engine also do not sound as tight since they need more clearance for expansion. 0.005" compared to 0.003"

r.c.rob · Nov 30, 2011

That cylinder looks like it had coolant leaking into it the way it is washed
clean. like a blown head gasket.
Rob

goforbroke · Nov 30, 2011

r.c.rob said:
That cylinder looks like it had coolant leaking into it the way it is washed
clean. like a blown head gasket.
Rob

It hadn't lost any coolant, so I'm assuming this isn't the case.

goforbroke · Nov 30, 2011

Throttle body and throttle boots looked good. Reeds looked good. I will change fuel filter, but I'd like to test injectors, is there a way to do this?

skibreeze · Nov 30, 2011

KJAssault said:
first thought is fuel filter i say this because my sled made it 452 mile on first motor do to plastic filings in the tank. it was the mag cylinder too and according to my polaris tech buddy that side goes first in a lean out situation. just put a new one on and cut the old one apart and find out start with simple stuff. as far as the rebuild depends on how much you want to spend. to me the pto cylinder looks fine and lookes like the 600 is separate jugs so pull one hone it new piston base gasket and run it. thats my 2cents good luck.

I really don't think any plastic filings came from the tank. The tank pickups are a screen type and much too fine to pass that type of debris. I'm not saying that a clogged filter is an issue, just not from this type of debris.

skibreeze · Nov 30, 2011

goforbroke said:
Throttle body and throttle boots looked good. Reeds looked good. I will change fuel filter, but I'd like to test injectors, is there a way to do this?

Not without cutting them out of the harness, mostly removing the motor and removing them and sending them off.

Personally, I just parted my POS 08 out after repeated issues over a 3 year period.

goforbroke · Nov 30, 2011

Thanks for everyone's help. Tear down is down. I'm going to replace both pistons, replace mag cylinder, send injectors in for a test and replace fuel filter. Still havn't found the cause. The crank looked unusual to me, I think the sled set outside for a year plus as pipe is really rust, should I be concerned?

skibreeze · Nov 30, 2011

Check for any vertical slop in the rods, the last time mine went down it took out the mag rod bearing and punched a hole in the bottom of the block. On mine, we changed out everything, and the longest it ever ran was 800 miles between kabooms.

KJAssault · Dec 1, 2011

skibreeze said:
I really don't think any plastic filings came from the tank. The tank pickups are a screen type and much too fine to pass that type of debris. I'm not saying that a clogged filter is an issue, just not from this type of debris.

not saying thats his problem but thats what happened to me. perks of being good friends with polaris tech is i know whats going on at all times and i get to watch. my 800 burned down we cut filter apart it was full of plastic filings. 4 of us standing there.

BB454 · Dec 1, 2011

burn down

You have something else going on there. That mag side looks awful dry to me. Lack of oil. Note the oil film on the PTO side compared to the mag. Sounds like the cylinder was hurt if you are going to replace it. Maybe the failure is lack of oil not lean. Check for loose or plugged oiler line. If it sat outside all summer, condensation in the oil tank may be your problem. I would drain it. Oil floats on water and if it had some in it the it would get injected.
You can buy a plastic syringe at the WalMart pharmacy and fill it with injector oil. It will fit right on the oil injection line. Push oil through the line and fitting in the case. Those fittings are a check valve so it will take a little effort. If you can't get it to pass oil then it may be clogged or stuck. I had one like that and pushed some brake cleaner into it and it freed up.
I do the syringe deal on all of the lines and fittings when I do a rebuild. Gets all of the bubbles out of the lines and lubes the bearings well. Easy insurance.

thefullmonte · Dec 1, 2011

Unless the picture is deceiving it looks like you have some rust formation in there. That may or may not have damaged the bearings, but that type of stuff always throws a red flag for me.

Pistons, you are always going to get varying answers on pistons. I have tried a lot of different stuff. Not because of a failure, but just general maintenance. I have never had an issue with any of them. I use my stuff, not abuse it. Always give a proper warm up. Stuff seems to hold together just fine.

Forging actually creates a very strong material, but it does have a higher expansion rate. Wiseco combats this by adding different materials during the forging process. Same materials that are used in cast pistons. I have seen Wiseco actually using tighter tolerances than stock and cast pistons in the Polaris 800 motor. I haven't heard of a single failure in those. SPI has come up with a new piston design in the last couple of years that appears very strong and is 50% more heat tolerant.

I'm not trying to start an argument about pistons. Just want to pass on more information. Either way I have more faith in the aftermarket pistons than I do in the stock ones.

Cylinder down, need advice

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