Polaris 2000 XCSP 500 Very Thirsty

[tutone]

Polaris 2000 XCSP500 Idles fine, boggy on take off, seems gurgly about until about 5-6000 rpm. The sled is also using quite a bit of oil. I have pulled the carbs and gave a quick clean. Only 1500 miles on sled. Runs great when you pin it. it does seem to pop and backfire right when coming off of idle or just feathering the throttle at idle.
Any help?

 

[whitedust]

Next check compression. Rings & pistions can go at any time for a lot of reasons.

 

[jim_golding]

A friend of mine bought one new and it would consume about 1 quart of oil ever 75 miles. He took it back to the dealer and adjusted the oil pump. He then got about 1 quart every 100 miles or so. In terms of performance, it seams you are running rich. How do the plugs look? Black, brown or white? My guess is black. Check what size of jets you are running and compare to polaris specs and go from there.

 

[xcr440]

Had the same problem, I'll bet it runs a lot better when its COLD. For most riding, I found by dropping the needle one notch in the carbs that cleaned it up pretty good. Still "gurgly" as you say when its above 25 degrees, but managable.

 

[fredster]

Polaris sleds almost always come jetted rich. Both 600 VES twins I have owned, I jetted down from 440 to 410 mains, with the clips set to the #3 position. I ride in MI which isn't exactly high altitude but high enough to need a leaner mixture. I don't ride below -10 or so. If you ride when it's super cold you might need to go up one size or drop the clips one notch in order to raise the needles.

I would suspect the 500 motor is jetted rich as well.

Both 600's got 10-11MPG with stock jetting and 12-13 with 410's. Plugs show tan instead of black. Throttle response is waaaay better.

100 miles per quart for oil is still high. My 600 Indy triple used a quart every 100 miles. Both 600 twins are around 120-150 miles per quart with the pump set to the index mark (there is a mark on the pump arm that should line up with another mark on the pump body). Many times, the oil is set a little on the 'rich' side as well......

 

[sledder33]

thirsty 500

XCR440 is probably on track. Dropping needles [ raising clips] is what changes your mid range. I would do a mid throttle plug test after dropping needles to make sure your not to lean. That should crisp up your mid range.

 

[tutone]

This sled is stock, I will try dropping the needle (raise clip) one notch.
Where is the best place to get 410 jets?
Thanks for your help!

 

[tutone]

The plugs look good, cardboard brown.
I see that the 410 mains are for the 600, what should I get for the 500.
My wife rides this sled, we did ride on Thursday and Friday, 12 and 5 degrees out respectively. the performance was a little better when colder but not much.

 

[skeeter2010]

Does the sled seem to run good when the power valves open? if so I had a fuel mixture screw tip break off and it would burn twice the fuel as everyone else. If you adjust them frequently you may want to make sure that they are both the same length. If I remenber correctly they are in the right side of the carb infont of the slide near the split line for the bowl.
This was on a TSB and that is how it was found
Good luck

 

[xcr440]

If your plugs are cardboard brown, I probably wouldn't mess with the jet sizes. If you do, read the plugs often!

I'd try the needle drop and see what that does for you first.

 

[fredster]

I agree, try dropping the needles one notch and see if that cleans up the midrange.

If your plugs are cardboard brown, your jetting is not too far off.

I think the 500 came with 400 or 410 mains. I would not drop more than one size if you are seeing dark tan already.

Oil pump - you will need to pull the carbs to check the oil pump setting. Look for a mark on the pump cam arm, it should line up with a mark on the pump body, and the cam arm should move as soon as the throttle moves (no slack or lag).

Other suggestion: pull your carbs and go through everything - all jets - make sure they are all clean and not damaged. Maybe something came loose inside....

 

[Duffy]

I would not mess with the jetting, it's not that far off from factory settings. It sounds like the power valves are not working properly. Clean the power valves completely, totally disassemble and make sure the blue adjusters on the end are not broken.

 

[tutone]

I pulled the carbs again last night, dropped the needles on notch. I also checked the oil pump, marks line up perfectly. The carbs are very clean and everything operates as expected. I will pull the exhaust valves tonight and see how they look. I did check and clean them last spring. hopefully I can fire it up tonight to see the resuts.

 

[artic570]

this sounds like you need to change spring in secondary clutch.
when spring gets weak secondary shifts too early and will bog engine down.
i've been told by a polairs guy this is not uncommon.
i think spring is about $20-$25.

 

[polarisrider1]

Set needle at #2 notch from top jet at 410 no lower for MI unless you want a melt down. That is for a liberty 600 VES. trust me on this. you can adjust your oil consumption. 100 miles to a quart is fine and safe.

 

[tutone]

Well I just came in from the garage. I had dropped the needles (clip is now in #2 position). The midrange seems better but it still is not running correctly right off of idle.
If I barely squeeze the throttle, it really gurgles and bogs. I would say that it ran better with the clip in the #3 position (just off of idle). It does smoke more than my other sleds.
The jets are stock. This thing really rips if you pin it. Not sure where to go next......

 

[fredster]

The only other carb tuning suggestion I can make for off-idle is the idle air screws. I think they are on the RH side of the carbs, so the PTO side carb screw is difficult to adjust. My wife's 2005 600 is very picky about this. Too rich and it's boggy when above 20 degrees. Too lean and it has a stumble when the temps are colder. I've tried different settings with minimal improvement. Somewhere around 1.5 turns is the factory setting. You might try turning them in or out by 1/2 turn and see if you get any improvement.

If this has no affect then perhaps one or both idle circuits are partially blocked.....?

Does the sled also bog with the track in the air? If the problem is the same with the track off the ground that would suggest the carbs and not the clutch springs since the track doesn't create much resistance when off the ground.....

I agree, difficult problem to solve.

 

[tutone]

I have messed with the idle air screws a bit. it seems that they need to be turned out quite a bit (3 1/2 turns out). I thought that this was excessive.
the bog starts well before clutch engagement and I feel that the issue is most likely carbs. I have not taken apart the flat slides (4 screws for large plate). Do I need to take this off in order to clean the carbs completely?

 

[xcr440]

Just an FYI, my brother bought the '99 I have new, and I aquired it off him a few years ago. He had taken it to Polaris to figure this out the first two winters, and they could not get it right. I've learned to live with the off idle "gurgle" as you put it, and ride it like that. It's not bad like you say while your moving away from the idle, or WOT, but its just something I've come to deal with by feathering it a little as I get started. 98% of the riding I do I don't even notice it since dropping the needle a notch.

 

[fredster]

Definitely sounds fuel-related...

I have had one set of flatslides completely apart when I had a slide crack, and as I recall I was able to remove all the jets and do all the cleaning from the bottom - that is, remove the carb and flip it over to access the jets and passages. I also pulled the "idle/fuel" screws from the body and spray cleaned in that orifice, too.

Of course if you pull the body completely apart you can check for other issues.

The other "tuning" factor is to change the pilot air jets that are on the airbox side of the carb, they screw in the bottom area of the throat My 2000 motor's carbs has these, my 2005 goes not, and the 2000 definitely runs better off-idle.

3.5 turns for the idle screws seems really excessive to me! When I fiddled around with the 2005 600 and tried that, it idled poorly and had a bad bog. I think I would try to find out what the factory setting is for this and start there......