Strange Low Temp issue bogging issue...

[Shum]

You all were so helpful in diagnosing my last tough issue I thought I'd try again...

I just replaced an oil seal so had the motor all the way out. Put it back in and took it for a test ride on our lake, it ran ok but at 3/4 throttle it felt like the cylinders were not working together, or maybe it was running on 1, great low end... loads of power until about 3/4 throttle then just maintain speed running boggy... If I feathered the throttle it would 1 out of 6 times wind out fine and have top end power too. This was flat out on a lake.

Took it up a trail at 6 degrees and it started having no power at all, 15 mph max... temp was reading 120s... running boards were barely warm. If I turned it off for 5 mins and started again temp read 160 all the power I wanted for about 1 minute then more of the same boggyness. Limped back to the lake toward home got on the lake and it sputtered along at 15 mph then it cleaned up and went full power all the way home.

If I let it sit and idle the temp climbs into the 180s, as soon as I move it drops within a minute to 120s

I'm confused... stuck thermostat? busted water pump? The running at 120 degrees, would that cause it to run so bad? Doesn't seem so... Does the top end bog out relate to the other bigger problem...

I'm new to the sled and am learning a lot about it fast... Thanks for any ideas.

 

[Danbot]

Mine runs at 126 in the deep so I can't imagine 120 would make it run poorly. Sounds a little cold though depending on your snow conditions.
No code flashes when it's running bad?

If nobody has a good suggestion, I always go back to the basics with my 900 when something weird is happening:
-read the plugs
-test fuel pressure
-test TPS
-set TPS
-temporarily disconnect throttle safety switches, kill switch, handwarmers

 

[Shum]

Mine runs at 126 in the deep so I can't imagine 120 would make it run poorly. Sounds a little cold though depending on your snow conditions.

Snow was deep 12 inches on the lake and 18+ on the trail...

No code flashes when it's running bad?

Nope

If nobody has a good suggestion, I always go back to the basics with my 900 when something weird is happening:
-read the plugs
-test fuel pressure
-test TPS
-set TPS
-temporarily disconnect throttle safety switches, kill switch, handwarmers

Plugs were changed, the ones I took out were tanish/white... so maybe a tiny bit lean??? but looked OK...

I'll read up on how to perform the other tests and see what I have going on there...

 

[Shum]

When I got time to look at it closer tonight, I noticed the Temp sensor wire was pretty much busted. I finished it off and got 3 flashes on the Service Light (of course). Temporarily fixed the sensor, and the light went back off. Took it for a ride and it seems to be back to normal. Running in the 140s, plenty of power, no bogging, no cutting out. I didn't ride it much (10 mins) since it is snowing like mad and dark, but that seems to be what my issue was. Found a used sensor locally off a part out sled, I'll pik that up tomorrow.

BTW on the way home I picked up stuff to make a TPS sensor tool, any other handy tools I'll be needing owning this sled (teed that one right up for the skidoo guys)...