08 and 09 Dragon 8 owners news.

[mountainhorse]

Ski Breeze...very methodical as usual...

I really don't hear much of the 800's going down WOT... even on long hard pulls with boxes that are adding lots of fuel on hard, turbocharged, pulls.... Maybe you have a defective fuel pump that fatigues after some time... maybe a defective pressure regulator in the PFA. Maybe something else is causing the lean condition.

Most of the siezures seem to be happening from high-midrange operation without varing the throttle (like you would do in a mod sled). I'm sure there is someone on here that had there "pinch" happen somewhere else in the RPM band, but that does not rule out damage from midrange operation.

And yes, There DEFINATELY is a problem with these sleds... it is NOT "rider error".

These same fuel pickups, Walbro "smart valves" are used in all the Polaris CFi and Cat EFi sleds without issue.

Skibreeze: I think that if that hole was eliminated in the front pickup, this reason for burndowns could be eliminated.

If you want to test your theory... Replace the MP-17 in the front pickup position with an MP-16 (non bleed, 90 degree) and lest use know the results... no "smart azz" reply intended towards the you or your evaluation.. just a check and see approach.

You can purchase the MP-16 at http://www.autoperformanceengineering.com/html/pickups.html

2008/2009 Polaris RMK CFi PFA and hose assy.

Front valve MP-17, bleed
Rear valve MP-15, bleed

2005, 2006 and 2007 CFi all. (and some of the 2008/2009 CFi sleds depending on tank/seat combo.
Front and rear are bleed type MP-15 smartvalves.... no aeration/cavitation problems.

In fact, the 2008 and 2009 700 RMK's use the same fuel pickup assemby and PFA (pump, flange assembly) as the 800's... the same part, same pump same fuel pressure regulator, same hoses, same tank.... none of the problems that are the main topic of this thread with the 800CFi sleds.

There is a lot more that could be going on than to just lable it as the pump cavitaing and not being able to suck enough fuel (or sucking air). It may be, but that is not the only possible explanation for your AFR's going lean.

When was the last time you replaced your lambda sensor (O2 sensor) in the pipe?

Walbro SmartValve fuel pickups.

From autoperformanceengineering.com: These fuel pickups were originally developed for snowmobile applications [in the early EFI snowmobiles]. . The original Walbro pickups were the MP-10 [in the early EFI snowmobiles]. Those pickups had a 30 micron screen. With fuel formula changes in recent years, the snowmobile manufacturers were noticing a type of goo building-up on the pickups. That goo was the new fuels reacting to the plastic fuel tanks. Walbro changed the mesh to 70 microns and there was no more buildup on the pickups. The new part numbers are MP-12, MP-13, MP-14, MP-15, MP-16 and MP-17.

How they work:
Have you ever sprayed water on a window screen? Recall that the screen will actually hold some of the water. These pickups work the same way. When the pickup is submerged in fuel, gas will pass through the mesh with ease. When fuel sloshes away from the pickup, the mesh will hold enough fuel to fill all the tiny holes. That mesh full of fuel acts like a solid. At this point, the pump, sucking on the outlet will cause the mesh to suck shut, preventing the pump from sucking air. When fuel covers the pickup once again, the valve will open up and transfer fuel.

These pick-ups have one or two 5/16 fittings. The pickups with two fittings can be used to connect pickups in series.

Walbro suggests that at least one pickup in the system should have a bleed hole. If your system doesn't have a bleed hole, it can become totally closed if all of the pickups close at once. If that happens, the closed pickups can take several minutes to re-open, depending upon how much vacuum the fuel pump has pulled.

The inlet side of the pickup has a 70 micron mesh. The pickup is just under three inches in diameter and just under two inches tall. These pickups have been tested in gasoline to -40 F and in diesel fuel to 0 F.

Note:
If the fuel pickups are completely dry, the pump will suck air. The pickups won't close unless they have been initially immersed in fuel [the mesh is wet].

Bottom and top of a MP-15 smart valve... MP-17 is a 90 degree model.

 

[skibreeze]

Mountainhorse, The complete FPA was just replaced and it acts identical to my original one. They both have bleed holes in the front and rear pickups. My next plan of action is to replace the front with one that doesn't have a bleed hole. IMO the system only needs one and it should be in the rear. I have taken both FPAs and put them into tubs of fuel and the pickups with the bleed holes start sucking air thru the bleed holes after 9-10 seconds once removed from the fuel. I have also ridden the sled with both FPA's and have the same results with both. I can see no other reason for my sled to lean out, especially since it does not do it when full and won't do it on flat ground either. It only does it on long climbs and letting off the throttle a bit does not help, you have to get the sled leveled out for the AFR's to return to normal. So it is not just a full throttle thing. My question is, is it possible that the FPA's are only supposed to have bleed holes in the rear? Are some of them assembled with the wrong parts, and I just happened to have 2 FPA's with 2 bleed holes?
EDIT The wide band is new as of a month ago.
The only good news from this w/e's ride is that I didn't score the new pistons while troubleshooting this issue.

 

[mountainhorse]

All of the fuel pickups on the 2005, 2006, 2007 units that I have here have bleed holes on the both pickups...

I agree, there is no need for 2 pickups with bleed holes.. the link above will take you to the website to purchase the MP-16 90 degree NON bleed pickup...$26... cheapest I've been able to find.

Keep in mind, that once the gas drains off the screen, the smart valve will open and suck air... this usually does not happen in a closed tank with some sloshing going on.

Let us know how it goes.

Keep in mind that the majority of the engine claims are coming from flatlanders on their 800's so, although this may be an additional problem... I dont think it is the reason for the majority of the piston/cyl issues.

 

[skibreeze]

MH, you are once again, a wealth of information. Great link for those pickups. I have already ordered a sheet of buna-n rubber and was going to make a new stopper. I am not saying that there aren't other issues causing burndowns. In fact That has been part of my problem as I had a bad v.r. and ECU also. This is just another cause that I have and suspect that others may indeed have also. My take on the aeration of the fuel is that the leanout is a short duration for most riders. This short duration if done over and over will possibly score the pistons a little at a time, getting worse gradually.

The first time I actually seized mine solid, it had @900 miles on it. Since then I have pulled the exhaust valves during the day and after rides, so I was able to see what damage was done after every ride and never locked it up. I think that most guys are riding them until they lock up completely. I pulled my ev's today and luckily I didn't score the pistons yesterday. I credit the wideband for saving the pistons as every time it leaned out while climbing, I saw it and was able to let off the gas and turn out. This happened 5 or 6 times yesterday, so, this has been repeated over several rides now.

I don't think that there is a fuel flow (quantity) issue as the injector duty cycle has never come close to maxing out.

Thanks again for the link.

 

[Head West]

Skibreeze,
i am not familliar with the fuel pump setup on the dragon, i assume it is in the tank. is it possible that you have a some kind of leak on the suction side of the pump. maby it only sucks air when you have less than half a tank, climbing, and the pump is not submerged. just a thought, i wish i was more familliar with the fuel side of these 800's.

best of luck, keep us posted

 

[skibreeze]

The complete FPA was just replaced and it acts identical to my original one.

As I stated earlier, the entire assembly has been replaced. I also tested both assemblies in tubs of fuel so I could see exactly what was happening. Both assemblies, all 4 pickups will aerate fuel 9-10 seconds after being lifted out of fuel.

 

[irastroker]

Both my 08 D8 and 09 D8 is in the shop no fix for fuel map on the 09 and new piston and cylinders on the 08 still they have not got it right. But Polaris is doing somthing for Polaris boys take it easy.

 

[Daggerboat]

MH , nice pictures/info! I'm hoping that I'll NEVER need to run a fuel injected sled but I guess I better start learning about them now just incase...Keep posting CFI info for us old school carb guys !

 

[800poodragon]

Dropped my 08 800 Dragon off today for end of year servicing. Service manager asked if I had changed fuel filters...said some kind of bulletin came thru a bit ago recommending to change fuel filters....had not heard of that one. Of course so far I have 2500 miles on mine and it seems to keep running better.....knock on wood......

 

[frog]

May be old news but what I heard is that the mechanical side of the engines are fine, it is a software issue. local dealer has a few flatlander 800's that went south and Pol said to rebuild them with no worries about the hard parts and that there will be a new program out in the next 60-90 days to remedy all the issues of the 08 and 09 sleds. The season is overe her in MN and that is why pol is not hesitating to repair them cause they know that the sleds will not be used until next season and by that time the new program will be out.

 

[Cardiac Kid]

There are some problems with hard parts because after waiting a month for parts and writing letters, new cylinders and pistons finally showed up. They put them together and the piston clearance was out of spec with all new parts. Polaris told them to put it together so I could ride, (Yeah I'm finally ridding again). So just a note this maybe something to check on. I sure am looking forward to a full yr of riding without a problem, maybe in yr three.

 

[diamonddave]

Intersting info Mountainhorse and Ski Breeze. Both of your posts lead me to a couple of questions.

Ski Breeze, have you monitored fuel pressure also during your climbs when you found AFR's going down? How about operating voltages? Is it possible that during these WO operations that the operating voltage can't keep up with the fuel pump, injectors, ECM, etc.? If the stator can't keep up, then low voltage will cause all sorts of poor runnability issues, ie fuel pressure, injector pulse, ignition timing. Running extra items will only magnify this issue.

Has anybody had their injectors flow tested after their first burndown? An issue we had with the skidoo 1000 SDI injectors is that the location and design would allow carbon deposits and the injector would prematurely cause issues. Also, the SDI's had a low pressure pump that made sure the high pressure pump was always submerged in fuel, so no chance of airation.

How about adding a battery to a sled like Ski Breezes? Have E-start sleds been having any issues? Don't Struthers CFI Bigbores come with different injectors?

With issue to the same fuel pumps being used in 700's and not possibly being an issue, I wouldn't bet the farm on this one. The fuel requirements, timing, etc. have to be different and may make it perfectly adequate for a 700 and not for an 800. Remember, fuel injection runs alot closer to the edge than your daddys carbs so there may not be enough of a saftey net.

It's going to be intersting to see what becomes of all this.

 

[skibreeze]

Intersting info Mountainhorse and Ski Breeze. Both of your posts lead me to a couple of questions.

Ski Breeze, have you monitored fuel pressure also during your climbs when you found AFR's going down? How about operating voltages? Is it possible that during these WO operations that the operating voltage can't keep up with the fuel pump, injectors, ECM, etc.? If the stator can't keep up, then low voltage will cause all sorts of poor runnability issues, ie fuel pressure, injector pulse, ignition timing. Running extra items will only magnify this issue.

Yes, oddly the PSI stayed at 58 psi even with the AFR's going thru the roof. The voltages mean nothing as far as this problem goes. You can fill the tank and it will not lean out again until fuel level goes down again.

Has anybody had their injectors flow tested after their first burndown? An issue we had with the skidoo 1000 SDI injectors is that the location and design would allow carbon deposits and the injector would prematurely cause issues. Also, the SDI's had a low pressure pump that made sure the high pressure pump was always submerged in fuel, so no chance of airation.

How about adding a battery to a sled like Ski Breezes? Have E-start sleds been having any issues? Don't Struthers CFI Bigbores come with different injectors?

With issue to the same fuel pumps being used in 700's and not possibly being an issue, I wouldn't bet the farm on this one. The fuel requirements, timing, etc. have to be different and may make it perfectly adequate for a 700 and not for an 800. Remember, fuel injection runs alot closer to the edge than your daddys carbs so there may not be enough of a saftey net.

It's going to be intersting to see what becomes of all this.

...

 

[logger155]

Any one want to buy my 09 dragon. It runs bad *** no problems at all. I once heard to blurp the gas all the time on the trail like a mod sled and that solves your fuel problem. I've done that the whole time and mine works great. 1200 miles and counting.

 

[skibreeze]

After 2 months of tearing down my motor after every single w/e, I now have ridden it for 3 full days with only one small mark on one of my pistons. I have been watching O2 readings constantly and just like the previous rides, they only go lean while climbing and at 1/2 tank. Over the last 5 rides, it has probably gone lean 20 times. Since I am watching the wideband while climbing, I can let off the throttle and turn out when it has happened and this is the only reason that I haven't scored it again.

I have ordered another pickup w/o the bleed hole for the front pickup and I am convinced that it will solve the lean issues that I have been having. It was actually wierd not having to work on my sled after Sat and Sun rides.

 

[skibreeze]

I emailed my dealer to find out where my parts were at that were supposed to be shipped out on the 10th and he told me that the kit had been discontinued by Polaris. They now have to order the block and pistons seperately.

 

[hilinerider]

the block and pistons the same part numbers???



if your cylinders are good why the block change?? porting??coolant passages???

 

[skibreeze]

Polaris had a kit that included all the top end parts. The kit is now discontinued. I need a new block and pistons because of the scoring on them.

 

[Cardiac Kid]

I thought the kit only included the Pistons, Head, and Exhaust springs. The Cylinder was not included as far as I know, and has always had to be ordered separately.

 

[undergroundrmk]

Kit

I thought the kit only included the Pistons, Head, and Exhaust springs. The Cylinder was not included as far as I know, and has always had to be ordered separately.

Had mine done with the kit it was as stated above!