I have 3 updates under my hood of an 07 FST.

They read like this:

S.07-ABC
S.06-10
S.07-02A
Does anyone know if these are the latest?
I can't find anything online except for the last one.
They are all dated Oct 7, 2007

The 07-ABC is to correct the location of the oil cooler restrictor.
The 07-2A is the chaincase shim kit update.

Is the " '08 update" one of these, or do you just take it for granite that the dealer did them?

The 08 ECU update was not available before November 19th, 2007. So that suggests you do not have that update.

If you provide your dealer with the VIN # for your sled, they will be able to tell you what updates have been performed to that unit. Or at least what updates were claimed to be done to that unit. If you are unsure if the '08 reflash has been performed, I would run it into a dealer and have them reflash it with the new program again just to make sure.

A quick check is to look at the boost reference hose on the sled. The new update hose that should have been installed is clear (as opposed to the stock black hose). This hose runs from the blow off valve up by the intercooler to the fuel rail behind the motor. It runs between the engine block and the primary clutch and should be wrapped with reflective heat tape at that point. If this hose update was not done, I'd bet that the reflash was not done either.

I had my dealer check my VIN and they said it was up to date. However, the updates were performed prior to 11-19-07 when the 08 update came out.
I found this online and will show them as it is at the dealer now.


Technical Service Bulletin S-07-11: Polaris is updating all model year 2006 and 2007 FS and FST snowmobile models with the corresponding 2008 Electronic Control Unit (ECU) calibration. When the serviced bulletin is performed, the calibration in your ECU will be replaced with the model year 2008 calibration. The new 2008 ECU calibration files will optimize performance and eliminate a temporary false check engine light that you may have noticed when starting your snowmobile. If the service bulletin is not performed you may experience the false check engine light.


None of the update stickers have the S-07-11...................yet

Can a 06 fst be updated to 08 or 09 with no problems?

All FSTs get the newest ECU updates from Polaris no matter what the year. There are a few differences between the years regarding fuel tank design and wiring harnesses that are not provided by Polaris free of charge, but all ECU updates are as are any other updates for reliability (such as the new boost reference hose).

All '06 sleds get the '08 ECU reprogramming and the overboost function for 160hp.

Does the ECU control the boost and is the over boost the same as boost?

Yes and Yes. The "overboost" is an additional 10% of boost above the normal maximum boost. This "overboost" lasts for 4 seconds while the flipper is down all the way. You can get it again everytime you go below 6,000 rpm's.

The boost on the FST is electronically controlled by the ECU. This is done with the boost controller mounted to the inside of the stock airbox which is connected to the wastegate. The ECU allows you to have a normal ABSOLUTE boost pressure of 29.15 psia. What this means is that the ECU senses atmospheric (barometric) pressure, and adds boost so that you have a total pressure of 29.15. Sea level atmospheric pressure is 14.5 psi, so with that base line you would get 14.65 psi of boost through the turbo. At higher elevation, the ECU senses the lower barometric pressure and closes the wastegate less so that you get increased boost pressure through the turbo so that the engine is still seeing the 29.15 psia. Therefore you don't loose hp at elevation unlike a normally aspirated sled. At the elevations I ride at, I usually see around 18 psi on my manual boost gauge.

The overboost function (new for '08, and reflashed into the '06 and '07 FSTs) allows the ECU to exceed the 29.15 psia total for the first four seconds of full throttle operation. I think it is around an extra 1.5 psi or so through the system. In operation it gives you an extra 20 hp for those first few seconds. After four seconds, the ECU lowers the boost back to 29.15 psia. As 'beeler said above, you need to drop back below 6000 rpm to 'reset' ECU so that the overboost function will kick back in.

Now if only we could buy the Polaris Race only ECU programming that allowed for a much longer time span on the overboost.

It is very interesting on how this ecu thing works. Thanks for explaining it to me fellas!

my buddy is thinking on buying a dealer demo 08 lx is there anything he should look for before buying it, updates/recalls etc

'08's are good to go right out of the box.

Those of us with '06s and '07s just finished up all the R&D work for Polaris.

The updates/recalls just bring all of the '06 and '07 FSTs up to the '08 spec. IF there are changes to the ECU programming for '09 (and as good as the '08s run, I doubt it) there will be a notification in the fall and a reflash available sometime in late November. Most guys that have had an '08 and an earlier sled say that the '08s run better than the '06s and '07s even with all of the updates done.

If there is anything that is deemed by Polaris that is a necessity for the rest of us that is being implemented on the '09 model, they will let all of us FST owners now about it in November so that we can haul 'em all in for the round of 2009 updates. One thing I will give Polaris credit for is standing behind this sled for the majority of issues that it had when it was new. There are still a few odd things that Polaris has dropped the ball on, and the one big issue: the front arm failure on the M-10 suspensions. And there are still a handfull of sleds with some interesting one-off issues. However, I think the failure rate of the '08 FST is much lower than any other full size sled that Polaris sells other than perhaps the completely bulletproof 550 fan.

user Pete Z ran my vin and checked everything...VERY HELPFULL!
http://tinyurl.com/3ag3bk