2012 boondocker kit run problems

BDTURBO said:

There are a couple of different scenarios that could be causing problems

The first is a fuel pick-up issue. We have found that at around ¼ of a tank some Pro-RMK’s will sputter and pop. This problem seems to be more apparent while on an incline and when the engine is under full load at full throttle.

The second possibility is that the machine is over-revving and hitting the rev limiter. The rev limiter on the machine is at 8500 rpms and we have found that the tachometer doesn’t always keep up with the engine, so if your tach is showing 8450 rpms it’s likely that the machine is running at 8500 rpms and hitting the rev limiter.
We have found that the 2012 kits are building more power so rpm’s are higher. This over-rev condition can be fixed with clutching or by lowering boost.

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Mountainhorse: 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.

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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 let us know the results... this is not "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.

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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].

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

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Originally Posted by BDTURBO:

The first is a fuel pick-up issue. We have found that at around ¼ of a tank some Pro-RMK’s will sputter and pop. This problem seems to be more apparent while on an incline and when the engine is under full load at full throttle.

Click to expand...