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Discussion Starter #1
I have an old Polaris Big Boss 6x6 that keeps dying on me. It started happening slowly over time, weeks, now every time. I have to keep revving it to prevent it from dying at idle. . . So, it seems the natural / obvious cause is the idle jet in the carb. However, wondering if I should also be looking at the ignition / spark system(capacitive discharge system, components) too? OR, something I have yet to consider. . . before I start tearing into things. Thanks up front folks!
 

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It may just need a carb adjustment due to a change in fuel - alcohol blended fuel raises octane by emulsifying a hard to ignite cool burning fuel with a fast burning hot burning fuel - Polaris calls for 87 octane non ethanol gasoline or 89 octane 'oxygenated' (alcohol blended) fuel at a minimum, but a higher octane will not harm the engine unless you go to the extreme - anything over 95 octane will cause a loss of power and high exhaust temperatures - you might even experience a loss of power with 93 octane, so try to stay around 89 to 91 octane non ethanol for best results.

When I said a change in fuel; just filling up at a different retail location in the same community is a 'change' in fuel. If you gas-up from a gas can and the gas in the can is over 3 weeks old, it's stale or becoming stale - I always try to buy gas from a busy station - the gas will deteriorate in the underground tanks - if a station is 'slow' and does not refill their tanks for months, you can get bad gas right from the pump. Alcohol blended fuel has a 100 day shelf life under ideal conditions - non-ethanol fuel had about a 2 year shelf life.

So, if your fuel changed (brand, age, alcohol, non-alcohol, octane rating, additives (by you or retailer)), the fuel screw may need adjusted to compensate for the change in fuel - it is possible the pilot jet is gummed up from gasoline residue or algae (the ethanol producers are making ethanol from algae instead of corn or other grains) - the process of making alcohol from algae does not kill the algae and if a small amount of water (.04% by volume) is absorbed by the ethanol from the atmosphere, the algae starts to grow and clings to parts inside the float bowl and fuel tank. The pilot jet is somewhere in the neighborhood of .0018" - a coating of algae or varnish 5 ten-thousandths of an inch thick can reduce the size of the pilot jet by approximately 50%.
 

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Discussion Starter #3
Man, detailed information, THANKS "late bird"!
You must be an engineer(like me).

Ok, so here is an update:

-- Since original post I charged up the battery, I was able to get the Big Boss started and drive 'er up to the house. After that, next day, zip. Won't even start even with fully charged battery.

-- I brought battery into O'Reilley's and they told me the battery is "Good" based on their battery charge meter.

-- Since then, I cannot get it to even FULLY turn over the engine: the starter solenoid clicks and then I get a bit of a Whirr, but the engine is not likely being turned enough to allow a cough! The "pull" cycle might be lasting a second and a half before it stops. Sounds like the starter does not have the amps to crank.
-- I then tried pull starting a few times to no avail. However, two days ago pull-starting successfully got 'er going when the click and whirr symptom occurred.

Here is a link to my Dropbox for a MP4 sound file of the starting process earlier today:

This next link sounds similar but is from AFTER I again FULLY charged the battery. Charging took over an hour. I was surprised at that. Head lights shine brightly.


So: 1st thoughts coming to mind are. . . drum roll please. . . bad starter, CDI unit or associated coils dead.

I have scoped out the Resistance values and harness locations to assess the CD system.

It appears we are not even to the point of carb coming into play here so I am prioritizing the sparky and turn over parts of the equation. Just the same, how could the sparky stuff impact ability to idle. . . Is that a possible contributor to poor idle too?!

thanks for your high end expertise in advance!
 

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Starter first:
Sounds like a bad battery - try a car battery and jumper cables (do not have the car's engine running if the battery is still in the car) - connect the jumper cables to the ATV's battery leads with the ATV battery disconnected - try starting, if it sounds the same then I think the starter might need to be replaced.

No, I'm not an engineer - I'm a mechanic and a shop owner with a degree in electronics, a business management background and some machinist training thrown in.
 

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Discussion Starter #5
What I love about somebody that has REAL experience is that it does NOT matter that, for example, an auto parts company used their under counter whizz-bang tester that brightly displays "GOOD BATTERY!" HA! Just dispassionate assessment with simple logic to arrive at a concise understanding and MORE real assessment.

I will check 'er out. thanks again.
 

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Discussion Starter #6
Well. THIS is not good news. I used my truck battery (Truck starts fine, 5.7 Liter V8) and bypassed the ATV battery and sounds the same, barely cranks. I again tried to manually start and got a few "puffs" out of the engine, more than any elec. starter attempts. Whatever the case. . . a new starter. I see the CLUTCH must be removed FIRST and after reading the service manual on that it is quite a Pandora's box and I don't have the tools to hold the spring pressure. NOT a job for me! Any idea how much a dealer is likely to charge, ball park even? It may be time to part this thing out.
 

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The clutch comes off as an assembly - only a puller is required - take bolt out of the center, insert puller and pull the clutch off - remove inner belt cover - remove recoil cover if necessary, remove starter motor, install new motor, replace recoil cover and test starter - if all is well reinstall all parts removed and go back to joy riding.
 

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Discussion Starter #8
OEM Polaris starter is $420 vs $80 for Quad Boss delivered to my door.

. . . While looking at pricing options I noticed Quad Boss's website also offers starter clutches. . . I recall hearing the clackitty run-on whirring sound that is likely the gear kicking out and spinning. . . So, I figure I need that also. Do you agree? Any chance THAT could be the only problem, not the starter? Is there anything else inside in this area I should consider replacing also since it will be all apart?
 

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OuadBoss are Firepower both re-branded Arrowhead starters - all are good quality Chinese units - it's always a good idea to install a new Bendix - they run dry on the Polaris and wear quickly - the only other parts under the recoil cover that is involved with the electric starter are the bushings the Bendix is carried in - if visibly worn, you might consider replacing them too.
 

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Discussion Starter #10
I was reading over the service manual and came on a picture of the puller required. Not like anything I have. I have a couple of traditional pullers with 2 or 3 jaws. This thing looks like a specialty bolt. Having 2nd thoughts on doing this myself. attached the relevant manual pages. Is this puller highly special? OR, am I missing something?
 

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It's actually pretty simple - bolt with an un-threaded shank threaded portion screws into the clutch - un-threaded portion pushes against the end of the crankshaft - thread size is 3/4 - 16
 

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I have an old Polaris Big Boss 6x6 that keeps dying on me. It started happening slowly over time, weeks, now every time. I have to keep revving it to prevent it from dying at idle. . . So, it seems the natural / obvious cause is the idle jet in the carb. However, wondering if I should also be looking at the ignition / spark system(capacitive discharge system, components) too? OR, something I have yet to consider. . . before I start tearing into things. Thanks up front folks!
Inside the throttle assembly there are electrodes just need to adjust to increase the gap and bring your idle up
There is adjustment under the boot leading into the throttle
Had the same issue on my 500 sportsman last year
 

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You tube
Polaris sportsman no idle fix
1:57 minute video might save you lots of time, money, and aggravation
 

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Discussion Starter #14
It's actually pretty simple - bolt with an un-threaded shank threaded portion screws into the clutch - un-threaded portion pushes against the end of the crankshaft - thread size is 3/4 - 16
So, I just need a machinist to turn down the lower end of a 6" x 3/4" bolt. . . I can do that. THANKS!
 

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Discussion Starter #15
Inside the throttle assembly there are electrodes just need to adjust to increase the gap and bring your idle up
There is adjustment under the boot leading into the throttle
Had the same issue on my 500 sportsman last year
thank you. I probably have that problem also, which is the main subject I started with but this situation changed to not even being able to start the thing. Regardless, I will check that out right away. Such a simple thing to mess up. . . hmmm.
 

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Discussion Starter #17
I jumped with my truck battery(bypassed old battery, including the starter solenoid) and got it started actually after holding the jumper cable ON for about 10 seconds. Still, the whole time it sounded like the thing was really laboring and then finally started coughing semi-continuously so I let go and . . . it continued to run. take away here is the thing "seemed" like it was trying to start from a nearly dead battery. Truck battery is fine. This is different from two days ago when I did the same thing but did NOT go around the solenoid.

Idled slow, but uniformly. The neutral light blinked ON/OFF and when I pressed for a bit more RPM it went steady. This may be an indication that the idle is, in fact, too low-- not enough alternator juice being produced to keep an idiot light lit.

However, my throttle control does not look like those in the U tube videos. See attached. It appears the "ETC" is a simple micro-switch that is reversed when throttle drops to idle and flips position when throttle pressed. Simple ON/ OFF, no spaced gap or electrodes. From service manual the only thing I see to adjust carb is AT the carb, using the idle adjust screw for my 1999 Big Boss. Again, this is NOT the big problem: Simply starting is.

The fact that it actually started may mean the starter is not(?!) the problem but, regardless, I shut it down and tried starting a 2nd time and after 3 pretended cranks and no coughing I pulled the jumper cable. So, no start now. hmmm. Possibly just more affirmation that it IS the starter.
 

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Discussion Starter #18
I jumped with my truck battery(bypassed old battery, including the starter solenoid) and got it started . . . Possibly just more affirmation that it IS the starter.
Followup detail:
on 2nd try to start it went like this: a very slow grinding crank lasting about 1.5 seconds, 3 sec of silence, then repeated this sequence twice more before I pulled the cable off.
 

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That throttle switch is strictly a safety. If the throttle cable freezes or siezes when you let off the throttle, that switch closes and kills rpm on the motor instead of staying open and potentially creating a runaway atv. You can test it by revving your engine then grab the cable in there with your finger and then let off the throttle. The switch should close and the rpm should cut out like the reverse limiter. I don’t think it kills the engine, just limits it.
 

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Starter is a good start haha. They aren’t the toughest thing on the planet.
 
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