2012 RMK Pro cuts out starting to climb hills

[lunytnz]

I have a new-to-me 2012 RMK 800 Pro that runs great for a couple of hours, then it starts to act up. It's an intermittent problem; it doesn't happen *every* time I give it throttle.
As I give it throttle to start climbing a small hill, it will cut out. If I work the throttle back and forth, it will go, again, but then cut out again. Unfortunately, it's cutting out when you really need it most (climbing).

Just in case it's helpful/related: it has an air/fuel gauge, which indicates it is running rich (15-16 range) most of the time. It also seems to run hotter than prior machines I've had (180-200 degrees). It also has a turbo.

On the last ride, while on a road where I could maintain speed for a while, it would bog/surge while holding the throttle steady. It would bog down to about 4,000 RPM, then surge to 5,000 RPM, every few seconds, before settling back at the 4,500 I was trying to hold it at.

What might be the most likely culprit?

 

[Over budget]

I have a new-to-me 2012 RMK 800 Pro that runs great for a couple of hours, then it starts to act up. It's an intermittent problem; it doesn't happen *every* time I give it throttle.
As I give it throttle to start climbing a small hill, it will cut out. If I work the throttle back and forth, it will go, again, but then cut out again. Unfortunately, it's cutting out when you really need it most (climbing).

Just in case it's helpful/related: it has an air/fuel gauge, which indicates it is running rich (15-16 range) most of the time. It also seems to run hotter than prior machines I've had (180-200 degrees). It also has a turbo.

On the last ride, while on a road where I could maintain speed for a while, it would bog/surge while holding the throttle steady. It would bog down to about 4,000 RPM, then surge to 5,000 RPM, every few seconds, before settling back at the 4,500 I was trying to hold it at.

What might be the most likely culprit?

Check your reeds. Or just might need to be dialed in on fueling numbers. Could be electrical. Try new spark plugs. Correct fuel that meets how much boost your trying too run. Then there’s your clutch condition. And clutch calibration. Clutch belt condition. Could be several things. But for how rich your AFR numbers are I’d start by checking your reeds first if you haven’t already.

 

[PSI 800]

is it cutting out or is it detonating. 2 different things. It could be your Knock sensor picking up a noise or be toast, or reeds like OVER BUGET said. I had a set of injectors on my NA 15 pro that were intermitent that did the same thing your describing. would det and shut down at the worst times.

 

[lunytnz]

Check your reeds. Or just might need to be dialed in on fueling numbers. Could be electrical. Try new spark plugs. Correct fuel that meets how much boost your trying too run. Then there’s your clutch condition. And clutch calibration. Clutch belt condition. Could be several things. But for how rich your AFR numbers are I’d start by checking your reeds first if you haven’t already.

Thanks for the tip about checking the reeds... I wasn't thinking that could be related, so I'll look into it.

 

[lunytnz]

is it cutting out or is it detonating. 2 different things. It could be your Knock sensor picking up a noise or be toast, or reeds like OVER BUGET said. I had a set of injectors on my NA 15 pro that were intermitent that did the same thing your describing. would det and shut down at the worst times.

I'm sure it's not detonating. The day before, I wasn't running high enough octane fuel and I got the DET error a couple of times, which also tells me the knock sensor is working properly. That didn't happen after I bumped the octane up to about 93.
It's definitely cutting out, not just hitting an RPM limiter. Thanks for telling about your experience with injectors... these intermittent problems can be a bear to nail down!

 

[Spiderman]

Check the throttle safety switch and tether if you have one...

 

[chevy_man]

You're getting a lean bog and lean heat. I'd bet your pistons hate life.

Pour the fuel in and get down to 12-14:1. Error on the side of too fat first and then lean it out until it's happy.

 

[ditch1000]

I had a 2014 Assault doing similar things and thought the fuel pump was on the way out.. I did find that the capacitor can be problematic on these sleds so II replaced that… No more issues with bogging; I guess I have a spare fuel pump now too …..
Seems like the voltage was just low enough for the sled to bog and throw the DET on the trail..