Hi guys,

I have a 2008 Polaris Sportsman 700 EFI X2 which won't run.

Back story - A month ago I sunk it. Puddle was way deeper than I thought. Wouldn't run afterwards, turns out the line that goes from the reed to the air box had a crack in it and sucked it full of water. Noticed low compression (120 and 90). Motor would fire and run for a few seconds, but then die. So, new top end, pistons, etc. Compression is now good (135, rings aren't seated yet, no run time). Spark plugs are brand new. Everything is dry. However, I can't keep it running. It will start and run for a second, then die. Every now and then, I will get a spectacular backfire (wife and dogs come running). Giving it a shot of ether doesn't seem to do anything, it won't stay running on it and doesn't seem to make it start any faster. It actually ran great with only the left plug in the motor while I was trying to clear the right cylinder for a compression check. Gas is good. Fuel pressure is good.

I believe I have a weak CDI box, but am unsure of how to test it. Any suggestions on how to test the CDI box or if I have another issue (stator)? The service manual had a blurb about how the ignition system gets its power from the battery and not the stator, but no testing information on the CDI box.

 

There is no test on the ecu,plus problem can be in the tbap or tps sensor harness connector or wiring,a crank position sensor harness wire grounding to the starter,etc can cause no or erratic spark. Rather then throwing parts at it since it was swamped and even if rebuilt,I have it on Digital Wrench to help trace the problem down the problem area. You could pull your hair out and just throw parts at one when Digital Wrench could possibly go right to the problem. Actually cheaper in the long run rather than guessing.

 

OPT, thanks for the info. The more digging I do, the more stumped I become.

My spark tester finally came in. I am getting spark... all the time. I cleaned out the fuel tank, blew out the fuel lines, cleaned the injectors. Fresh fuel. No dice.

Checked crank sensor, it is within spec (manual calls for 560, I was at 548 but it was a bit colder (50* vs 68 as recomm in manual).

Kill switch in handle bar and throttle safety is fine.

I don't have the fuel injector tool as required in the service manual, is there a way to test them?

Here is a startup vid:

http://vid140.photobucket.com/albums...psnsy8navd.mp4

 

Problem can also be in the tbap or tps sensor or usually the wiring and connector itself. You can do a visual check of the connectors,clean and reinstall to the sensors,plus check for any damaged or soft feeling(melted) wires from the tbap or tps.Any problem in either one can keep an atv from cranking.Better harness repair kits are available if needed.https://otbpowersports.com/products/ Again if you rule out either of these and the connectors and wiring,I'd give Digital Wrench a chance.Only so much you can check out with the manual.

 

Thanks OPT, I am familiar with OTB.

Question for you, is there an easy way to check the timing on these 700s? Or do I need to remove the flywheel and pull the cover off?

Also, is there a compression release/decomp?

 

You need to look at your manual.. The crank position sensor sends an ac signal to the ecu which which processes this and determines the ignition timing. And also no compression release. Again that's why sometimes it's hard to track down problem areas on efi machines without it being hooked up to Digital Wrench.

 

OPT, I was referring to the camshaft timing gears... I know the dots need to be lined up, but is there an inspection port/cover? I don't remember seeing one.

 

Nope.

 

I know it's a long shot but pull the flywheel nut and see if the woodruff key may have split and the flywheel may have moved. This can screw up things also.

 

OPT, my quad has been in the Polaris shop for over a month now. Seems it has been quite the doozy as everything I checked pointed to "OK." Their lead tech has finally advised that the oil pressure regulator is bad, causing over-pressurization, oil seeps past the rings, causing the valves to float. This sort-of makes sense to me, as it did blow out an oil filter seal when I was trying to get it running.

My question to you is, I'm being told that the oil pressure regulator plunger is seized in the block. Do you know of any ways to get it out? He's already tried a magnet hydraulically pushing it out with the oil pressure. Tech said that the next step is to pull the motor and either dril/tap a hole and use a slide hammer, or drill a hole in the block to push it out as he doesn't believe there is a way to get at the plunger directly.

Thoughts?