2008 Polaris dragon rmk 700 injector help

[alaskanpower]

Good morning, I am asking for help in how to clean the injectors on my sled which is a 2008 Polaris dragon 700 rmk. I have narrowed it down to a possible clogged injector which is the bottom ones, I have watched how they cleaned injectors on YouTube but does not have anything for the dragon is detail, I know there are 4 injectors, it runs but but dies when on idle, checked fuel pump, changed fuel filter, psi is good, cylinders are good, just running on one cylinder, pto side is always wet, I changed the spark plugs a couple of times and would backfire, initially thought there was water in the tank but I emptied out the tank and put in fresh gas which ruled out water, any help would be appreciated thanks in advance

 

[sledhed]

I know on my Dragon 800 when I was having injector problems I had the injectors out of the sled, if I recall I applied voltage to it to open the injector and had a WD40 can spray tube in the fuel inlet and could see the spray coming out the injector. That way I knew it was not blocked. They aren't easy to get out by any means especially the bottoms.
Have you checked the fuel pressure itself, especially when the motor is running (or sort-of-running)?
Also the injectors are opened using current directly off the stator, sometimes a stator that is failing can cause issues...
You know, if you really think it is the injectors, and you just want to get riding again ASAP, look for a set of injectors of same color (and I think they have to be off a 700 as the 800 are higher flowing (or so I heard) but you can check polaris parts microfiche online to make sure they are the same part number) off a sled being parted out on ebay. My problem was some kind of wiring issue where it worked off the sled but not in, so I bought a complete injector harness with injectors attached, no splices or anything, and slapped it in and was riding... which I prefer riding to tinkering if I have a choice.

 

[alaskanpower]

Thanks for the reply

 

[alaskanpower]

Would a tps cause it to run on one cylinder also?

 

[retiredpop]

No, the tps would not cause that. Both plugs fire at the same time regardless of which cylinder is actually going to ignite the mixture. If the plug is always wet then that indicates to me that there is fuel but no spark or a very weak spark. You mentioned that with fresh spark plugs it would backfire which is probably that cylinder firing momentarily. Is it possible that the crankcase is full of fuel in that side so the plug immediately gets fouled? There should be drain plugs on the front of the engine block. I suppose you could always pull the plug on that side and ground it so it can spark, then start the sled to see if there is a good strong visible spark. It may blow out any excess fuel if there is any in the cylinder.

 

[alaskanpower]

I didn’t see any drain plugs on the engine, I know the earlier versions had them in the front below the y pipes but I don’t see any on this sled

 

[alaskanpower]

I seen spark when I checked for spark, tried switching the coils and still the same,(could be needing new coils cause there’s rust around where the coils are)pto side is wet, idk if it’s a mix between oil n gas, I’ll check the wire harness and the grounds to see if I can find any loose wires

 

[retiredpop]

How about if you switch the plug wires? If it still fouls the pto side then you can rule out the ignition circuit as the cause.

 

[alaskanpower]

Thanks for the reply I’ll try that and see if that’s the problem

 

[alaskanpower]

Dang still no luck, changed the coil wires, still nothing, going to look through the wire harness

 

[alaskanpower]

The pull start recoil busted before, would anything cause it to mess with the stator to get low spark?

 

[retiredpop]

It's possible. Is that when your trouble started? There are crankshaft position sensors under there so depending if some debris got under the flywheel it could have moved or dislodged a sensor.

 

[alaskanpower]

I bought it used and the starter rope busted and the guy I bought it from replaced the rope, when I started it the first time I needed to hold on the throttle about half way in order to have it stay running

 

[alaskanpower]

I’ll try remove the recoil and see what I can come up with after I get a flywheel removal tool

 

[retiredpop]

I bought it used and the starter rope busted and the guy I bought it from replaced the rope, when I started it the first time I needed to hold on the throttle about half way in order to have it stay running

So when you held the throttle open did it sound like it was firing on both cylinders? I may have been misleading you regarding it being an ignition problem. It is quite possible you were right in thinking it is the low speed injector on that side that is giving you the problem. It looks like quite a bit of work to get at them. Once they are accessed I would think you just have to supply voltage to open the injector and then spray some cleaner through them.

 

[alaskanpower]

Yeah thanks for the info

 

[05rmksteve]

There is crank case drains on the motor. They're on the very bottom of the case.

 

[05rmksteve]

Is there a programmer on the sled or is it completely stock?

 

[alaskanpower]

Yeah it has a power commander fuel injection module

 

[05rmksteve]

Yeah it has a power commander fuel injection module

Unplug it and try running it with out it. I had a 09 800 with power commander that would start over fueling and the sled would act like it was running on 1 cylinder. I would have to unplug the power commander and run the sled for a bit then plug it back in and it would be ok for awhile.