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Troubleshooting a bog

Snowbird11

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I've had an issue with my stock 17 axys 800 since new (now just under 600 miles). It has an intermittent bog in the 5800-6100 rpm range and again at WOT under load. The WOT one is more concerning since it happens on a steep hill and when I need it the most it stumbles for a couple seconds. Lately the sled has been inconsistent on how many pulls it takes to start. Previously it was 2-3 pulls when cold and 1 when warm. Now it will occasionally not start when warm or after a start to check miles, it won't start without throttle input. Sometimes it feels like it is flooded when restarting after a bog.

I'm concerned that I have two separate issues. Tps and fuel pump seem to be likely culprits. I haven't checked either since I don't have pressure gauge and am not sure I should tear apart the machine to check the tps.

I might take it to the dealer next week but am not holding my breath. When new, I was told to keep running it and it will probably resolve itself after break in. So far I haven't noticed any codes to diagnose with. Any other ideas?
 

AKFULLTHROTTLE

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Man. so many things that can cause a bog. There is the relay issue, Exhaust valves, reeds but no way those are bad.

Also EGT sensor, they cause bogs and all kind of weird runnability issues. If you can swap one with a buddy it is easy to try.

Have yet to see a fuel pump be bad on an Axys but I guess it is possible.

The dealer really needs to run a self check on the Exhaust valves, Check pressure on fuel pump, digital wrench the TPS, Check compression. Also make sure something is not wrong with your clutch, is there any squealing at idle?
 

Snowbird11

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Man. so many things that can cause a bog. There is the relay issue, Exhaust valves, reeds but no way those are bad.

Also EGT sensor, they cause bogs and all kind of weird runnability issues. If you can swap one with a buddy it is easy to try.

Have yet to see a fuel pump be bad on an Axys but I guess it is possible.

The dealer really needs to run a self check on the Exhaust valves, Check pressure on fuel pump, digital wrench the TPS, Check compression. Also make sure something is not wrong with your clutch, is there any squealing at idle?



the clutching feels strong and belt deflection is good. i have not heard any squealing. i am running 10-60's but only hitting 8200 from 8k to 10k.

the dealer can't look at it until january 3rd, which should be prime riding time but the weather will tell. supposedly the dealer has their best troubleshooter on it so, i'm hopeful.

aside from the trail bog at 5800 or so, the sled feels very strong. if it wasn't for the upper end stumble at WOT i wouldn't even worry about it. that one has me concerned since it can and has put me in a bad spot before.

all symptoms have been present since new, so i disregarded the relays and exhaust valves initially. i have always been skeptical of the TPS & worried about the fuel pump, especially with the high end stumble. when it happens at WOT i can get through it usually by letting off and pinning it again. as recent as three days ago it was happening when playing in the powder and caused problems on restart immediately after.

https://youtu.be/mLk6zUQj6_U

an hour after this video i could not even get it to turn over without throttle input. a day later it started like usual.
 
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S
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their is a great right up on how to set the tps hear on this form and I would guess that's 1 of the problems but I don't know how much or if at all it effects the top end ....as for the bog at 5800 don't quote me on it but I think that's around when the power valves start to open. I would follow ak's recommendation and let them check the basics just don't take their word as gold if they don't find your problem it still could be something they checked and oked . they do a lot of digital wrench checks but that's not all ways the best way just the easiest.
 

AKFULLTHROTTLE

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Does it bog when you slowly go into the throttle or when you stab it?

What weight are you suppose to have at the elevation? I know if they over rev the will bog and also the tach wont keep up to show you. Just checking since 60 is way light for me since ours come at 70 but maybe 60 is right for your elevation, but seams to light. They will do weird things will not enough weight.
 

Snowbird11

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Does it bog when you slowly go into the throttle or when you stab it?

What weight are you suppose to have at the elevation? I know if they over rev the will bog and also the tach wont keep up to show you. Just checking since 60 is way light for me since ours come at 70 but maybe 60 is right for your elevation, but seams to light. They will do weird things will not enough weight.

The mid range bog only happens under light throttle on the way up. I never notice it on when backing off the throttle.

The high end stumble is after the throttle is pegged for several seconds.

Weights at 60gr are what people run around here for stock sleds. Two dealers recommend those and install as their stock elevation kit.
 

Snowbird11

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Gotcha, Leaning towards exhaust valve issue.
Are you thinking both issues are exhaust valve related?

The mid range one flutters and stays if you hold the throttle there but passes before you can audibly hear and notice the extra pull of the exhaust valves opening.
 

richracer1

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Does it bog when you slowly go into the throttle or when you stab it?

What weight are you suppose to have at the elevation? I know if they over rev the will bog and also the tach wont keep up to show you. Just checking since 60 is way light for me since ours come at 70 but maybe 60 is right for your elevation, but seams to light. They will do weird things will not enough weight.

FWIW, the service manual, at least for the '16 800 models, shows a 10-62 for 8-10K. Try putting those in, it may help the WOT bog as you may be bouncing the rev limiter....Just a suggestion
 
J

Jaynelson

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"The WOT one is more concerning since it happens on a steep hill"

For that one...a few simple causes could be:
- Too light on the clutch weights and hitting the rev limiter (as suggested)
- Also, if you are getting low on gas, that attitude will make it cut out
- Also have had it bog under that condition if the intakes are clogged with snow

As for the midrange cut out and weird starting - the first thing to check for any random Axys weirdness is always water intrusion in to the relays and connections above the primary clutch. They need to be dried out and re-installed with a little di-electric grease, and orientated in a way that water won't be held in the connections. Or the relays may need replacement if they appear to have been holding water for a long time. That can cause all kinds of random running glitches. No point in messing with anything until you're confident that and the weights are good IMO
 

Snowbird11

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First off, thanks to everyone for all the help and ideas. this place is a great resource!

FWIW, the service manual, at least for the '16 800 models, shows a 10-62 for 8-10K. Try putting those in, it may help the WOT bog as you may be bouncing the rev limiter....Just a suggestion

i have some 10-64's that i may try next time we get snow. all the other axys i ride with that are stock are using the 10-60's but mine may be running stronger for some reason.

would the limiter get tripped at 8200? i have never seen 8300 on my gauge for max rpm. i had 8250 once and more commonly 8100-8150 for a max over 10k. i spend some time at 7-8k but usually just to get to the 9-11k riding. the big pulls are always at higher elevations.




"The WOT one is more concerning since it happens on a steep hill"

For that one...a few simple causes could be:
- Too light on the clutch weights and hitting the rev limiter (as suggested)
- Also, if you are getting low on gas, that attitude will make it cut out
- Also have had it bog under that condition if the intakes are clogged with snow

As for the midrange cut out and weird starting - the first thing to check for any random Axys weirdness is always water intrusion in to the relays and connections above the primary clutch. They need to be dried out and re-installed with a little di-electric grease, and orientated in a way that water won't be held in the connections. Or the relays may need replacement if they appear to have been holding water for a long time. That can cause all kinds of random running glitches. No point in messing with anything until you're confident that and the weights are good IMO

mid-range:
i'll check the relays again but it started literally on mile one brand new under clear skies and cold temps.


WOT:
this occurs during both powder and firm spring snow.

most of my rides i end with more than half a tank and rarely put more than 50 miles (20 trail) on per ride. the last few times it ocurred was after 20-30 miles on for the day.

the clutch will get checked. is it typical to get a light when the rev limiter gets hit?
 

Snowbird11

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Finally got my sled into the dealer and the tech thought I may have bad gas, swapped the plugs and installed the new map. My gas is fresh non ethanol, the plus are about 2hrs old and the sled was purchase February last season, so I'm not sure what map it was running.

Anyone know if there has been a significant update to mapping recently that would help my issues?

Thanks
 

Snowbird11

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i should also add that the relays are all clean and dry, there were no codes present on the digital wrench and i'm still usually only hitting 8150 at 8k.

has anyone here seen higher rpms out of more clutch weight? seems counter intuitive but i'm willing to buy another set of weights if it's a possibility.
 

Snowbird11

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No, you will not go up in RPM with more weight.

well, i'm not sure what the trick is but i'll try the new map and see where i end up. it's been low rpm since new but sure pulls hard even at the lower rpms. wish i knew what the ideal rpm range was for my elevation. i'd sure hate to drop weight and increase rpm only to lose overall power to the track.

might try some indy dan clutching.
 

AKFULLTHROTTLE

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Have you tried swapping egt sensor with a buddy? or the map sensor as well? At least narrow it down. I have seen bad fuel injectors but if you have a buddy that you can swap parts with those first two or a easy one to try.
 

Snowbird11

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i'll look for a way to test out some parts in the future. i do have a couple friends that ride the axys as well.

as for the dealer fix. i picked it up today and see on the tech repair sheet that it was throwing codes, specifically a stuck throttle code 7 times. the tech adjusted the tps and changed the plugs. he also suggested a higher octane fuel. i've been running 88 non-eth since its is what i can find. he's suggesting 91 ethanol for now.

so far she starts and idles smoother. if we get some snow i may take a ride this weekend and see how it runs. i'm currently looking over the new mountain cat though. i wish the snow was better to justify it.
 
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