[dniksich]

I'm working on this for a friend and can't figure it out. It's a 2005 Ranger 500cc 6x6 and I can only barely get it to start with starting fluid. It tries to fire but just won't unless I spray some in it, just backfires out the exhaust. This is the second carburetor and the problem persists. Things I've tried/checked.....New carb, plug, adjusted valves(camshaft is fine), checked the fuel pump, pulled the flywheel cover off to check the key to see if it sheared and messed up the timing. Did a compression check and it's 75psi which is within specs with the compression release. The engine only has 700 hours on it. Only thing else I can think of is the cdi box maybe? It does get spark but does look kinda weak. Only thing else I can think of is the cdi. Anyone know of a cheaper 8 pin cdi? I see a ton of 6 pin boxes that are supposed to fit but this one's a 8. I really don't wanna spend 400 bucks on a oem box if I'm only guessing at the solution. Any one have any ideas on what I can try next besides a cdi? Thanks for any suggestions! This is driving me nuts! lol

 

[yooper265]

Backfiring is usually indicitive the valves are not adjusted correctly ...

Are you sure of the year of the rig ?
Here's a 8 pin , for a 2003 ,-

QuadBoss High-Performance CDI For Polaris Ranger 500 4x4 2003

QuadBoss High-Performance CDI For Polaris Ranger 500 4x4 2003Description: Raises rev limiter by 1,000rpm over stock boxes All boxes have monocurve technology Brand: QuadBossPart Number: 160-02120Fitment: 2002, 2004 Polaris ATV Pro 500 4x4 PPS 2002 Polaris Big Boss 500 6x6 2002-2003 Polaris...

lionparts.com

 

[dniksich]

I'm sure it's not the valves. Set both to .006 and yeah, just talked to the owner and he said it's a 05 Not sure if there's a difference in cdi's between 03/05?

 

[dniksich]

Backfiring is usually indicitive the valves are not adjusted correctly ...

Are you sure of the year of the rig ?
Here's a 8 pin , for a 2003 ,-

QuadBoss High-Performance CDI For Polaris Ranger 500 4x4 2003

QuadBoss High-Performance CDI For Polaris Ranger 500 4x4 2003Description: Raises rev limiter by 1,000rpm over stock boxes All boxes have monocurve technology Brand: QuadBossPart Number: 160-02120Fitment: 2002, 2004 Polaris ATV Pro 500 4x4 PPS 2002 Polaris Big Boss 500 6x6 2002-2003 Polaris...

lionparts.com

Any other suggestions on what I can try? I'm still stumped.

 

[yooper265]

Any other suggestions on what I can try? I'm still stumped.

Did you order this one ?

I;m guessing if you run the vin number it;s a 2004 , there's no 8 pin modules listed for 2005 ?

 

[dniksich]

Did you order this one ?

Not yet. I just messaged the owner asking if he's positive it's a 05 and not a 03 cause I do see 03's had 8 pin cdi's like you shared. If it is a 03, I'm gonna get one. I'm guessing if it's a 8 pin for a carb setup, then it should work.

 

[yooper265]

Not yet. I just messaged the owner asking if he's positive it's a 05 and not a 03 cause I do see 03's had 8 pin cdi's like you shared. If it is a 03, I'm gonna get one. I'm guessing if it's a 8 pin for a carb setup, then it should work.

Run the vin on one of the free online sites

 

[dniksich]

Run the vin on one of the free online sites

It's supposed to be in the front left wheel well correct? It's so muddy, it's hard to see anything under it. lol

 

[yooper265]

VIN Search | Polaris Sportsman

Enter your 17 digit VIN number to find important information about your Sportsman or Scrambler ATV such as engine serial number, model number, factory warranty, extended service, guides, manuals, product recalls and safety bulletins.

www.polaris.com

 

[dniksich]

I think you're right about the year. I can't get the vin cause the frame is rusted where it is and he has a push bumper on the front so I can't open the hood. I don't know if this matters but the manual has a copyright date of 2002 in it. I'm gonna order the cdi you shared and hopefully this fixes it since I think I checked everything else out now.

 

[CrazyElecE]

I would do a leakdown test, it will tell you more than compression test.

ETA - if it runs on starter fluid I would focus on the carb, not the ECU.

 

[dniksich]

I would do a leakdown test, it will tell you more than compression test.

ETA - if it runs on starter fluid I would focus on the carb, not the ECU.

If the cdi doesn't help, leakdown is about the only thing left. It starts on fluid but won't stay running unless I'm holding on the throttle. On gas it tries to start but just can't catch enough to start. This is the third carb(including the original) I've tried and they all do the same thing.

 

[CrazyElecE]

Have you verified the timing on both the crank and cam? or spark plug gap?

 

[dniksich]

Have you verified the timing on both the crank and cam? or spark plug gap?

Haven't verified as far as timing marks cause I didn't pull the flywheel but the chain is tight so I'm guessing it didn't jump time and the flywheel key is ok so that didn't move. Plug gap is .28 The owner said the problem just started out of the blue. One day it was good and the next day it wouldn't start.

 

[CrazyElecE]

I haven't worked on a 500, but the ones I have worked on it's actually fairly easy to get them to jump timing. It's a known issue with Polaris and the hydraulic tensioners. Should be timing marks on the flywheel and cam gears that all line up at TDC of the compression stroke if it's like the others.

 

[dniksich]

I haven't worked on a 500, but the ones I have worked on it's actually fairly easy to get them to jump timing. It's a known issue with Polaris and the hydraulic tensioners. Should be timing marks on the flywheel and cam gears that all line up at TDC of the compression stroke if it's like the others.

I'll look into that and see where the marks are. Hopefully I don't have to pull the flywheel off to see the mark. Thanks.

 

[dniksich]

Checked the timing marks and they're lined up. I'm lost.

 

[TexasDave]

I'm working on this for a friend and can't figure it out. It's a 2005 Ranger 500cc 6x6 and I can only barely get it to start with starting fluid. It tries to fire but just won't unless I spray some in it, just backfires out the exhaust. This is the second carburetor and the problem persists. Things I've tried/checked.....New carb, plug, adjusted valves(camshaft is fine), checked the fuel pump, pulled the flywheel cover off to check the key to see if it sheared and messed up the timing. Did a compression check and it's 75psi which is within specs with the compression release. The engine only has 700 hours on it. Only thing else I can think of is the cdi box maybe? It does get spark but does look kinda weak. Only thing else I can think of is the cdi. Anyone know of a cheaper 8 pin cdi? I see a ton of 6 pin boxes that are supposed to fit but this one's a 8. I really don't wanna spend 400 bucks on a oem box if I'm only guessing at the solution. Any one have any ideas on what I can try next besides a cdi? Thanks for any suggestions! This is driving me nuts! lol

When you say you are on your second carburetor, is it a genuine Mikuni carburetor or a Chinese knockoff? I have an 03 (series 11) that had similar issues and it was the carburetor. Tried the knockoff and like 90% of the people they don't work or don't work for long. I had to get a Mikuni and it's been running ever since.

 

[dniksich]

When you say you are on your second carburetor, is it a genuine Mikuni carburetor or a Chinese knockoff? I have an 03 (series 11) that had similar issues and it was the carburetor. Tried the knockoff and like 90% of the people they don't work or don't work for long. I had to get a Mikuni and it's been running ever since.

Just a knockoff. I'm just guessing but I'm thinking it's not a carb issue since this problem started with his original carb and I've since tried 2 different ones with the same result. I can't think of anything to try next besides drain the tank and try fresh gas. He used it everyday so the gas in it now didn't sit for long so this is a stretch but at this point, why not.

 

[Rangerwhit]

Rebuild the OEM, which I hope you still have. I'm one of many who wasted money and time with a knockoff.