Polaris Axys 800 Cold Start Flooding

[carstensnow]

I have a 2018 Polaris Axis RMK800 (original owner). In the last two seasons it has become increasingly more difficult to cold start the sled. Dealer made a TPS adjustment to the high side to increase idle RPMs (runs now around 1800rpm idle). Still ongoing cold start flooding issues. It did not do this for the first few years. Mostly occurs when temps drop below 30F. I typically do one slow pull to turn the engine, then try starting it. Typically after 3-4 pulls the engine is flooded and I have to pull plugs. Once running the sled runs great, zero issues when engine is warm or at high rpm performance band.

I have found some threads on "850s cold start flooding issues" that suggest trying different plugs. I am running BPR9ES. Some suggest going to BPR8ES or BR9EYA? Is there still any merit giving the airbox an Ether injection to help with cold starts? Any input is appreciated.

 

[BeartoothBaron]

Does it only occur when it's cold, or has starting gotten worse any time it sits a while? I'm assuming the TPS was adjusted to factory spec; if they had to run it outside of that range to "fix" something, you've got other problems, and will probably cause more. I run BR9EYAs - they come highly recommended for the 800s. I wouldn't bother with ether, other than a one-time situation where you've got to get it going for some reason. Does it fire at all before it floods out? If not, I'd look into TSS and ignition culprits first. If you can verify it's getting spark when it happens, I'd start by checking and cleaning the injectors, then verify fuel pressure, then start digging for electrical issues. Could maybe be reeds or due for a top end too. Diagnostics aren't always easy on these; sometimes it boils down to "check everything," because there's no obvious culprit. When everything is healthy, you should be starting in a few full pulls even well below zero. I just pull hard on cold starts: it takes some effort, and you only get a revolution or two on the first couple when it's cold cold, but it's always started.

 

[carstensnow]

That is very helpful, thanks for the input. I will keep diagnosing this and post an update.

 

[Perk]

I'd also consider the coils and stator/stator connections.

 

[HECKS]

Hopefully it's as simple as a different plug change. Check plug gap, should be 27 thou.
I use to have issues on my dragon like the flooding you described when cold. Eventually we would unplug the fuel pump and sled would fire right up and idle until out of juice. Ended up wiring in a switch onto the console to the fuel pump plug and when it wouldn't start after 3 pulls I would kill the power to the pump, then next pull the sled would fire up, then hit the switch to power again and good to go. Chaulked it up to leaking injectors.

Lots of factors as mentioned above, but an easy one to test is if it's still flooding to unplug the fuel pump. Plug is fairly easy to access on the Axys'
You could have a look at the reeds and ohm out the plug wires and caps to be sure as well.

I fixed a buddies '17 Axys where the coils were the culprit, but it would start and idle fine. They ohm'd out on the high side but still in range.
It would randomly shutdown on the trail at varying throttle inputs.
I believed once the coils were warm they were intermittent. If it sat for 10-15mins and cooled off, it would run for 1-15mins again before dying.
Service manual states to ohm test the coils at 68F, and note the coil connector colors for PTO/MAG side and be sure plug wires are going to the appropriate cylinder.
Below is from 16-17 Manual, but 18 should be no different.