Several Service Bulletins were announced Augst 30, 2006, as well as a Team Tip for the 2006 FS/FST snowmobiles. The fixes apply to the engine packages, regardless of which model snowmobile they are installed in.


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S-06-06 Service Bulletin 2006 FST ECU reflash, Alternator Heat Shield Replacement.

1. This reflash is what we expected, it is the 2007 ECU programming fileset or reflash. This 2007 FST calibration will provide the 2006 FST with improved cold-weather starting, reduced plug fouling and improved fuel economy and performance. Reminder: the 2006 FST was rated at 135 hp. The 2007 FST is rated at 140 hp, so this should be a 5 hp. improvement.

2. The 2007 FST alternator heat shield has been redesigned to prevent engine and turbocharger heat from melting the alternator regulator / rectifier pack. This is most likely to occur at slow speeds in deept snow with ambient temperature above freezing. All the 2006 FST heat shields are being replaced with the 07 shield.

The fileset download has been available for a while, the 5250865 Alternator Heat Shield is also available.

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S-06-07 A/B Service Bulletin 2006 FS Exhaust Manifold Replacement (NOT FST)

A few 2006 FS exhaust manifolds had cracking, they are all being replaced.

the 1261726 FS Welded Manifold will be available 9/15/2006

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S-06-08 Service Bulletin 06 FS/FST Oil Cooler Sleeve Insert Update

To prevent oil dilution and rising oil levels, Polaris is installing an oil cooler sleeve insert to restrict the amount of coolant allowed to flow thru the oil cooler on all 06 FS/FST snowmobiles. Once installed the oil temperature will be maintained at the temperature required to "flash-off" any unburned fuel within the oil. A similar, but different (not interchangable) sleeve will be used in the 2007 FS/FST sleds.

2203426 Kit 06 FS/T Oil Cooler Sleeve will be available 09/08/2006

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S-06-08-01 Team Tip 06 FS/FST Erratic Fuel Gauge / Melting 4-way coolant tee

1. Fuel level sender and MFD display tolerance may cause erratic or incorrect fuel level reading on the MFD gauge. Intallation of the Fuel Sender Jumper will improve gauge accuracy by 1 to 2 gallons.

2. The 4-way coolant tee fitting can contact the exhaust silencer on 06 FS/FST sleds and melt. Polaris is recommending the use of 2 panduit straps (cable ties, etc.) to fasten around the metal air intake tube, and then pull the 4-way away from the silencer, but not so far that it contacts the steering drag link with the skis centered. Details and a picture are in the tip sheet.


2410580 Fuel Sender Jumper is available now. 2 14" panduit straps are locally available!

fyi... I spoke with a mechanic at my dealer and was told the 07's have alot of changes including different pistons.

0453178 is listed as the piston,ring & circlip for both 06 and 07 FST engines, EXCEPT for the 07 FST IQ LX, which uses a 0452993 piston,ring & circlip. There is no previous number listed at this time. They all list the same connecting rod.

thanks for the info Excursion.

I had the jumper installed in April when Polaris was testing it (you had to ask the dealer to call Polaris for the jumper). It doesn't really change the accuracy of the fuel gauge, it just reads at a higher level for a given amount of fuel. I did a lot of testing with and without the jumper adding 1/2 gallon at a time and checking the gauge reading. I will have to dig up the without jumper values but basically with the jumper my gauge reads as follows:

1 bar = 0 - 0.5 gallons
2 bars = 1 - 4.5 gallons
3 bars = 5 gallons
4 bars = 5.5 = 6 gallons
5 bars = 6.5 gallons
6 bars = 7 gallons
7 bars = 7.5 gallons
8 bars = 8 gallons - full

This will keep the low fuel level indication from coming on until you are a little lower on fuel than it did before.

The jumper is just a resistor, the problem with the gauge is that the number of ohms read from the fuel sender is linear with the tank level and does not account for shape of the tank. I also have the resistance values and the corresponding fuel gauge readings and I will dig those up as well. I have a friend who is an electrical engineer and he is going to try to come up with an electric circuit that will correct the tank level reading.

Why not fix the issue of gas getting in the oil instead of trying to cover it up by boiling it off???? Getting the feeling we're in for another dissapointing year of troublesome riding.

Hope I'm wrong

Bluetoy,



Do you think this engine management recalibration will reduce gas in the oil?

Excursion,
Thanks for the heads up. I called my dealer this morning to check out the service bulletins. I'm optimistic that the FST will be a better sled this year. And now with the updates for the '06's, it's sure be the sled we all expected it would be.
Do you mention that an engine/ tank heater was to be available for the '06 FST?

Once again I appreciate keeping us informed on the latest and greatest.

I am not an engineer, but the very poor fuel economy (rich run) issue surely would contribute to, if not be the problem with the fuel getting into the engine oil, thru all the modes it can get there. So reprograming will do all the things that everyone wants as far as increased horsepower, improved mileage, hotter running engines, etc.

I am sure getting the engine to proper engine temps would also help, but it seems that the fix is one that is very labor intensive (replace thermostat) and probably is not something Polaris wants to do without trying the aforesaid first.

As far as the fuel gauge issue, I think that is a pure cop-out on the part of polaris and clearly a bandaid on a fracture process. For those who need to be reminded, one of the MCS members took the time and trouble shot the fuel sender finding that the float does not cover the distance it needs to cover to give an accurate reading of the actual level of the fuel in the tank. That member found by bending the fuel float rod to the correct bend, does make for accurate measure and will be the ONLY way to actually cure this ill. Adding a resistor to the reading only tricks the gauge into reading a level of fuel that doesnot exist, either too much or too little. The result will be a sender that says you have lots of fuel and then within miles you will see a gauge reading the opposite and warning of too little fuel.

And I am willing to bet that the 2007 units have the correct bend on the rods right from the get go. Either way, the only way to correctly reflect the proper level of the fuel is to pull the tank, and the sender, and correct the bend on the float.

I will also be looking for a good inline thermostat to supliment the one in the engine to get the machine up to 180 degrees as quickly as possible. That will take care of the too cool of coolant issue also and is a fairly easy fix.

The 2007 FS/FST models have a redesigned, larger fuel tank and a different sending unit and float, to go with the larger tank. Polaris says this 2007 tank will not easily retrofit an 06 FS/FST.

The snowmobile Engine Block Heater is not an update, actually more of an accessory. It comes in two flavors:
2876168 Engine Block Heater for 110 volts available 9/22/2006 $70 list
2876200 Engine Block Heater for 220 volts available 10/02/2006 $85 list


Also a note about the S-06-06 reflash.

It is only needed for the 2006 FST to get it to the 2007 FST calibration.

The 2006 FS should get the S-06-02 PERC-4 reflash (announced February 10, 2006). For the 06 FS, that is the same as what the 2007 FS have from the factory.


And a note about S-06-08 oil cooler sleeve.

The function of the oil cooler sleeve is not so much to restrict the overall coolant flow, as it is to prevent coolant from flowing into all the SIDE PASSAGES in the cooler where the coolant would actually remove heat from the oil.



Smokeless1,

As you know the engine coolant manifold is 'plugged in' to the engine via two nipples with o-rings. It has an outlet on the right that goes to a very short fat hose elbow and into the front tunnel heat exchanger. This is what gets most of the flow when the thermostat opens at around 160F.

The 'bypass' labeled outlet on the left, goes to the front radiator and oil cooler. This receives all the flow until the thermostat opens, then it receives some flow.

Where do you plan to install an inline thermostat?

ON both lines.

We have the benefit of others who have not waited for polaris to fix this issue. Those who have extracted the 150 degree thermo and put in 180 (which is no small task), have already indicated their results. This upgrade to the thermo, also lets the engine run at optimum temps instead of having it continueously running in warm up mode for improved fuel economy, (not running on the warm up portion of the ecu), and letting the motor run where it should run which is between 180 degrees and 220 degrees. This temp will take away lots of the "other issues" which the Polaris engineers are reverse engineering to on this sled.

EXCURSION
Keep up the good work I relate

No. Getting the engine up to normal temps might help. If the new reflash fixes this why is there a need to boil off the fuel? There's only one way to get gas in the oil, washing the cylinders down from running insanely rich.

Oh and bending the fuel level rod works excellent.

If the ECU remap changes the fuel ratio to 14.7 to 1 instead of the 12 to 1 it was set at... Won't that reduce fuel in oil?. I thought it was just putting more fuel in the motor than it could use.

If the Choke sticks on older cars it will fill the oil system with gas. Why would these sleds be any different?

There are two things which will reduce fuel in the oil.

1) lean out the burn mix. This is being done by the remap. This reduces the air fuel and the blow-by will not be so fuel rich. As the blow-by gets into the oil, the oil is relatively cool causing a condensation issue in the oil. If you get the oil temps up to 180 or more, then you will reduce the condensation of the gas in the oil where it can be reburned. This should also improve the life of the engine.

2) By increasing the engine run temps, the mapping will lean out the engine even more (just like your car or truck does) and this too will improve fuel consumption, and reduce the blow-by into the oil, but with warm oil, now will condense less and evaporate at a much faster rate that which does get into the oil.

Question??

Will getting the engine temps up AND the remap actually cause the engine to run too lien? I am hoping that the Polaris engineers flattened the curve to account for warm running and it won't. On the other hand, if they did not then the remap might be counter productive to engine life, and promote a lien burn issue.

Polaris needs to take care of both sides of the equation here. If they do not then running on an engine that is perpetually in a warm-up mode is not going to do anything to the longevity of these engines. I am beginning to loose that warm fuzzy feeling here.

Based upon the extremely poor fuel mileage for a 750cc 4-stroke that we've been getting along with the obvious gas in the oil, fouled plugs, etc.. i'd say that we have quite a ways to go before we start going the wrong way. I'll take that chance. Polaris has alway been know to run "a little rich" and i feel confident that they won't go overboard on this change. Why would they? I'm certainly no engineer so i'm only going by my gut on this one but knowing Polaris i doubt they'll make a desperate change to these sleds. They've had a year to work on these and i'm betting we'll be getting what we should have gotten last year.

Yeh, well since they are putting a different thermo in the 07 sleds, seems a bit odd that they are not retrofitting the 06 with the same thing, except that it is a not so easy fix by the dealer meaning more work time and more costly repair. Seems that we are being left behind on the obvious improvement.

Actually, if you look closely, Poo has addressed the fuel issues. They have issued the remap and in my opinion were clever to increase the oil temp in the oil cooler instead of the whole engine. (water temp)

We are all assuming that the remap will lean out the fuel mixture when in fact it may just be timing changes or lowering the warm up temp\mixture and changes to other perameters. I hope that it is a fuel remap, but only Po knows for sure.

Poo says it will improve cold starting, better fuel economy, and reduce amount of fuel in the oil. Thats enough for me to assume its a remap of fuel delivery. :beerchug:

Huh??

The oil runs thru a cooler which super cools it before it runs back to the tank, then the engine coolant circulates at 150 degrees which is where mine stays unless I am sitting at idle for 5 minutes; rest of the time it gets back to 150 degrees. In my opinion, Polaris missed the mapping on this engine significantly in the intro and that is why the fuel efficiency never reached expectations. But that same over dosing of gas, has keep the engine running cooler than expected, caused poor fuel economy, and is probably at least most of the reason the silencer glows with excess fuel not burning til it gets clear to the muffler. Liening this machine out is going to do all the things they say it will and cool things down a bit, but it won't be doing a dang thing about the engine temp thermo, since full circulation of the coolant will still be happening at 150 degrees regardless of the remap. That is why they put a hotter themo in the 07, which will help the engine get to a warmer state at normal operating temps. I think Polaris used the shotgun approach to this engine not being sure what would happen over a 70 degree variable temps....-30 to +40. So they riched it to be sure and then after finding out from everyone who has actually done the field testing, that they did not need to do that as it will most likely not overheat as was the issue of the 2 strokes and I think that is why they liened out the engine to where it should have been in the first place. Lien runs hotter but more efficiently and will keep the can from being a furnace.

I bet the most of that night time glowing of the can will disappear after the remapping is done and so will some of the melting issues.

Smokeless1, I've been reading your stuff and believe you have a pretty clear understanding of what Poo has done and will do with these sleds. I like your logic. I can also think of no other reason why they would change the thermostat model cept to run the sled at a different temp. Why else would they change? So it sounds like we really need to have the new thermo for our sleds and here's my question. Can anyone confirm the temp of the new thermo? and or is this new thermo number the "NEW" replacement number for our 2006 sleds?

Also, if the new thermo would help why not offer it to those that want to swap it out now instead of waiting until the season gets underway. Heck i wouldn't mind pitching in for the repair assuming Poo would give us a little break on the costs. C'mon Poo, step up here.

Yah, there is only one reason to change the thermo number...it is different and almost certainly hotter. But apparently they are not available yet. I suspect tho that if you want to dig way down to get it out and take it down to the parts store you could find one to fit. I think some have done that already, but you would have to go back to last feb or march HCS threads to find out where they found it.

Perhaps tho the easier way is to put an inline thermo in, such as they have on Motorcycles.

When I said Poo addressed the issues, I meant with the updates that have just come out, and have not been tried by us yet.
Small amounts of fuel in the oil is supposed to vaporize and get returned to the air intake. Everyone agrees the oil temperature has to be high enough for this to happen, not the water temp. They are raising the oil temperature in the oil tank by restricting water flow thru the oil cooler. Raising the water temperature is not needed. I am under the impression that the 07 thermostate is the same temperature, but has been improved to be more consistant opening and closing. If the fuel map reduces the amount of fuel getting in the oil, and the higher OIL temperature allows the small amounts of fuel to vaporize and get removed to the airbox, then I will be satisfied with the fix. It is also my opinion that the glowing pipes will still be there after the engine is leaned out. Time will tell wont it. :beerchug:

Well Beeler, as you say...the proof is in the pudding. We should know about the effects of the fix this winter. But here is what I am worried about.....(does it show that I am a glass half empty kinda guy??)

This Weber motor, is german designed, and was made to run in all sorts of applications, but mostly those where the engine will be run at higher temps, such as cars airplanes, water craft, as well as snowmobiles.

Running a super charged engine at 30 degrees colder temp MAY not be where it is the most efficient, but more importantly where it was designed to run at. You are forcing high charges of fuel into the engine by turbo, and common sense tells you that a warmer environment for the fuel will help in the combustion and do a more complete burn. If you are cooler then the burn is not going to be as complete and there will be more "washing" of fuel in the cylinders. This can't be good for the life of this motor. And the red hot muffler tells me that raw fuel is getting past the combustion process until it gets to the muffler where it gets enough oxygen to burn which is making it a small furnace and also leaving evidence in the blow-by into the oil.....lots of it. The fuel in the oil is indicative of this process. Can you flash off the oil by getting the oil hot enough...sure. But wouldn't it make more sense to get the complete burn in the cylinder and retrieve the energy that is stored there? Wouldn't it make more sense to keep the fuel from gettin diluted and washing down the walls of the engine?? Modern engines are designed to run in a full range of temps but just because they run there doesn't mean that this temp is at optimum for best performance. I know they can "trick" the prom into telling the engine that the lower temp is optimum, but that doesn't mean that the performance will follow at that temp, or that the gas washing will be eleminated. Running this engine at higher temps will improve the performance and prevent the washing process in the first place. It will also further reduce the burn in the muffler and reduce heat in an already hot engine compartment. Is that an improvement??? You tell me.

And that is why they put a hotter thermo in the new sleds but, does not explain why they did not call for the 2006 sleds to be retrofitted with the higher temp thermo. Seems to me that if you want the life of that motor to get where we all thing they will go, this temp increase will have to happen, or face the washing and burn off after the fact and the shortened life of the motor. The only thing I don't know about is how well the synthetic oil will hold back this thinned lubricant from doing damages. For that time will tell. In the meantime, I intend to fix this machine right with or without the help of Polaris. Clearly by putting the hotter thermo in the new sleds the engineers have decided that hotter is better. You figure out if your sled should have gotten the hotter thermo or not.

I talked to a rep. at the Polaris booth at Heydays today. Seems Polaris is figuring out the ECU update will want a warmer operating temp and in fact if the thermostat is not replaced, the motor WILL stay in warm up mode and creat the same too rich fuel problem they had last year. I felt by his conversation there will probably be and additionial update this fall. (thermostat replacement) Hope so...

Let's hope so because I wasn't looking forward to changing it, as we have 2 sleds to do.

If I have to loose sled time this winter to haul the sled back to get this fix done, when they have already figured out NOW that the sled needs to be run warmer for the reprogram to be most effective, I am going to be bummed. Lost some sled time last winter with the starter fix, and that was enough. Winter is too short to wait. I hope your conversation with the rep was on target and they get on the stick and put the thermo on the list of things to do NOW. I am gettin it done by my dealer next month so I can be ready to rumble in November.

Why are you saying the 07 FST thermo is higher temp? I have not seen anything yet that says that. You may be correct, I just havn't seen any indication. FST mentions a rep says a higher thermo may be in the works. I find it hard to believe that if that is the case, why are they not already in the 07's.

I don't think that Polaris would put out a new thermostat number for the 07, unless they changed the temp. If they had a problem with the thermos with the old number they would simply swap stock and keep the same number.

FST more or less confirms the change temp by his discussions with Polaris rep. Finally last winter somebody on here reported changing out the thermo at great effort, to hotter running and reported good results, with unmodified program. Just because outboards run around at 150 degrees doesn't mean that you can do that with snowmos. Far different environment, with far different issues. If cars and trucks would run better at the lower temps, they would run them there too if they could. They don't even in winter the machine gets up to 180 degrees.

Got to be a reason for that besides just doing it. Bunch more testing going on in that arena so seems that this would have proven itself one way or the other.

BTW what would be WRONG with warming the engine up to 180 degrees anyway?? Nothing I can think of.

My first thought would be the temperature of the inside sheave of the drive clutch. It runs way hotter than the outside sheave which tells me that heat is comming from the driveshaft and transferring to the inside sheave. I think a lot of the blown belts were caused from this heat transfer. I do not have a clue what 30deg increase in water temp would translate to at the driveshaft, but it cant help. Otherwise, I am not against a 180 deg. thermo. I just don't think we have all the info Poo has. I trust they will get it right.

It is routine for Polaris to assign a new part number when a significant change or improvement has been made to a part.

As an example, the 600 HO rubber carburetor adapters have had problems and they are being replaced with a new number. The old numbers even in dealer part stock are being returned. This is the most reliable way for Polaris to know that the warranty work and any spares sold to people are the newer improved version. If the old part number was reused, I do not know how their computerized stock and warranty systems could tell a new version from and old one.

what I did was remove the front heat exchanger and the hoses and my sled runs at a nice 165 to 170 all the time and I know my fuel mileage went up a little and I never had any gas in my oil
runs great

Let,er Buck :div20:

Removing the front heat exchanger is a lot of work!

Do you still have the coolant radiator?

My first reply, hope it works! Did you connect the front hose directly to the oil cooler or totally eliminate coolant flow to the oil cooler? Did you happen to check oil temperature?

There seem to be some questions still remaining on these MY06 Four Stroke updates for the 06-07 season. We will do it like Jeopary: here is the answer, you guess the question.

1. All the warranty parts required are available as of Dec. 11, 2006, in the Polaris warehouse in Medina, North Dakota.
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2. FST Heat Shield, FS/FST oil cooler sleeve, FS Exhaust Manifold, all need to be ordered by the dealer, they are not auto-shipped by Polaris. Too many people take their sleds for warranty to a different dealer than they bought it from.

3. A letter explaining these updates was sent out to all U.S. and Canadian dealers Aug. 30, 2006.

4. To be eligible for maximum warranty reimbursement (Master Servicing Dealer), dealers are required to have currently trained staff, and appropriate service tools and manuals, which are automatically distributed.