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Discussion Starter #1
I’m getting pretty close but need some confirmation. So, I’m out riding yesterday and after about 45 minutes I couldn’t throttle it over tip in without it bogging. Limped it back to the truck at about 25mph max. Got it home and it was still doing the same. I shut off the fuel and as the carb drained out it got way better and cleaned right up. Turn the fuel back on and it started to bog again. Turn it off and as it empties the fuel bowl gets right up again. Now I’m thinking the slide is hanging up. Easy to pull out the diaphragm and slide. Fiddled a bit and seemed to run fine. Could his be a slide issue? Can they be polished smooth?
Next issue. Spark miss throughout the range. It doesn’t matter cold or hot, idle or on throttle. New coil, and plug, no change. Anybody thinking pickup? Speedo issues? The rpm’s aren’t correct on the display and change when you turn the headlights on or change to high beams but, if I unplug the speedo it should eliminate it as a culprit, right?
Thanks in advance
Willshire


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Discussion Starter #2
One last thing on the bogging, has anyone had an issue with the intake boot leaking but only when its hot? I'm just wondering if this is part of my problem. Although i mentioned above that it cleared up when i popped out the slide and put it back in, the engine was i bit cooler when i did so. I guess the easiest way to find out is to ride it until it starts to fail and spray some brake cleaner at it?
 

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Discussion Starter #3
Well, vapour lock sounds like the issue I’m having so I will give that a go first with some exhaust wrap and heat shied for the gas tank. Especially since the tank was half empty when it started and we stopped for a minute and it started right after we got going again. Let you know what I find.


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So, vapor lock isn’t the problem, lol. I was leaning toward fuel pump but it only seems to do it when it’s hot. Then I went into some water, I doubt it even got to the spark plug boot but maybe. Then it got real bad. Cleared up back to the normal “hot bog” on the other side of the water. I noticed my vacuum to my fuel pump is erratic which on cars is a vacuum leak but, not sure on a cv carb. Anyone? Replacing fuel lines and carb vent line today. I’ll pull the carb if I have to. Maybe the intake boot has a leak? I will check that too. Maybe it leaks after the head gets hot?


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Discussion Starter #5
Fuel pump is pushing out a steady 1/8” stream and then burps out a larger quatity when you increase the throttle. It still has the miss through the rpm range. I put on a timing light and the light doesn’t flash during the miss. It does it through the rpm range. Also, if I soak the header and first joint of the exhaust with water it bogs down. Anyone experience this? Anyone? beuhler?


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Discussion Starter #6
Ok then. So the idle rpm seem fine on startup and for about the first minute or 2 then they seem to drop off without any change in engine rpm. It pretty much has a constant misfire throughout the rpm range and about 40 minutes of riding it falls flat on its face. Still charging to 14.4V. So I’m going to have to lean towards cdi and possibly the trigger coil but I would think the trigger coil can only trigger if it sees voltage from the cdi so maybe it’s charging up and then every so often it doesn’t charge/discharge. The stator is in spec, the trigger coil resistance is in spec, looks like I’ll have to bite the bullet on a cdi unit. Has anyone had these issues? Has anyone had a cdi slowly fail during a ride and then come back after the bike cools down? I can’t be the only one!!!


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I dont have a 500 so can answer the question specifically for you machine.

However, it is possible for electrical parts to fail intermittently when hot.

I'd hate to suggest buying a cdi before you test all ekectric components first.
 

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Discussion Starter #8
I dont have a 500 so can answer the question specifically for you machine.

However, it is possible for electrical parts to fail intermittently when hot.

I'd hate to suggest buying a cdi before you test all ekectric components first.
Thanks Mike. I guess I’ll have to run the bike with all of the front end off until it starts acting up and hopefully then I can get closer to the solution. It misses through the entire rpm range, after it starts to act up it idles fine but bogs on acceleration. If it does die, it starts right up and idles fine just no jam when you hit the throttle. I thought it might be the stator but it doesn’t matter if lites are on or off that’s how I got all the way to the cdi or trigger coil


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Discussion Starter #9
The dangers of reading too much. It “could” also be the stator. At $300, this isn’t a decision to be taken lightly. Not to mention the oil change that comes with pulling the flywheel. Ahh this is so irritating because other than the pickup coil (which you can get included in the stator package) is like $23. Other reasons to lean toward the stator: gets worse when the bike is hot and sat for a few minutes., has a constant misfire. And it’s attached directly to the hot engine. Really the only thing I could test was output voltage to VR, pickup coil resistance, and charge voltage to battery. All seem good. But as I have learned there are more coils in the stator that control ignition, than just the charge coils. Oh, balls!


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Discussion Starter #10
To you guys fighting this issue. If your battery is charging fine. It isn’t your stator. I read the wrong diagram in the manual and thought there was a source coil in the stator. There isn’t. Only charge coils. Move on to cdi or voltage regulator. Lol


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Discussion Starter #11
Another quick little update. It’s hard to see what is actually happening during the miss with an ohm meter on the trigger coil. My DMM has an analog sweep on it but it’s hard to follow.
Coil sees 140vdc with PVA
Stator puts out 18VAC at idle up to 80VAC at WOT (roughly)
Rectifier/reg output is 14.5VDC
I changed the float height on the carb and will install it tonight.
I will run it up until it is hot when it starts to bog and sputter usually 30 minutes of run time.
I have 4 digital volt meters back probing (MIG welder wire gets in behind the seals) the stator output, the cdi voltage input, peak volt adapter onto the coil, and an ohm meter on the trigger. Electrician not electronics tech lol
I will check all of these items referenced from cold checks to hot/bog/sputter checks. If they all check out the same, I’m stumped lol.
Note to you 2010-2013 sportsman ho guys, nobody makes an aftermarket CDI for these. Not sure the difference between 05 and 10 as they are physically the same with the same pin outs.
I will report back and let you know what I find.
As for the rpm gauge? Only the regulator or display could cause the faulty readings
Cheers
Adam


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Discussion Starter #12
Ok so, I put a Offshore carb on and my problems have disappeared. I swapped the jet needle from the mikuni and had to change the choke valve to the Chinese one. Set the needle to second from the top and now it goes like a scared cat. The float system on the offshore unit is a standard drop float with the main pickup tube as part of the carb not the float system. I thought it was electrical because it would miss even with a timing light. I guess I learned something. The rpms are still wonky without the lights on but I can live with that. If you are having the issues in this thread, try a carb. $75 cdn to your door from amazon. Cheaper than any electrical part so a good place to start. If that’s not it, you can return it or be out $75. I drilled out the slide lift holes to 7/64 instead of 1/8”. Works like a champ!
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