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2012 polaris 800 low RPMs
- Thread starter xc500mod
- Start date
D.B. Cooper
Member
1) Fuel filter
2) Check the exhaust valve rubber diaphrams for rips/tears
3) Check the Throttle body boots for rips/tears (twist and move them around, flashlight close up)
4) Take some vice grips and pinch off the rubber hose form the ex solenoid to the "T" to rule that set-up out
5) Compression check?
6) When you have the exhaust valves out, take a light and look inside the bores to inspect the sides of the piston
7) Clutch springs
2) Check the exhaust valve rubber diaphrams for rips/tears
3) Check the Throttle body boots for rips/tears (twist and move them around, flashlight close up)
4) Take some vice grips and pinch off the rubber hose form the ex solenoid to the "T" to rule that set-up out
5) Compression check?
6) When you have the exhaust valves out, take a light and look inside the bores to inspect the sides of the piston
7) Clutch springs
Last edited:
1) Fuel filter
2) Check the exhaust valve rubber diaphrams for rips/tears
3) Check the Throttle body boots for rips/tears (twist and move them around, flashlight close up)
4) Take some vice grips and pinch off the rubber hose form the ex solenoid to the "T" to rule that set-up out
5) Compression check?
6) When you have the exhaust valves out, take a light and look inside the bores to inspect the sides of the piston
7) Clutch springs
thanks for the responses, i'll have to wait until next weekend to tear into it. it's just too cold around here, i'll use the bro in laws heated garage over the weekend.
This sounds pretty simple, but try a new belt. I fought with my RMK for a year on RPM's, with at the time, I thought was a belt in great shape. What I didn't realize had happened was that that belt had worn enough that it never got up in the sheaves high enough at top throttle, thus limiting the RPM's. Was running consistently 7700 7800. Bought a new belt and instantly it ran at 8200 like it should.
motor_slut
New member
Clutch weights hitting the spider is the most common reason, followed by sticky exhaust valves, or a scuffed piston.
raceinsnow
New member
I hate to say this but check the compression,loss of rpm on that motor is the first sign of the motor letting go.I hope that is not the case but check the pistons for damage.
I hate to say this but check the compression,loss of rpm on that motor is the first sign of the motor letting go.I hope that is not the case but check the pistons for damage.
raceinsnow, what should the compression be on these motors? send me a pm with your phone number or email just in case. i am going to tear into it this weekend. i'll keep everyone posted.
D.B. Cooper
Member
raceinsnow, what should the compression be on these motors? send me a pm with your phone number or email just in case. i am going to tear into it this weekend. i'll keep everyone posted.
Varies with gauge and engine temp and elevation
but 115 -125 is what I'd like to see
If it's low, remove the exhaust valves and take a small flashlight and look inside the bores
You'll be able to see the sides of the pistons
Look for lotsa "blowby" (darkness BELOW the rings) and or "smeared melted aluminum" on the skirts
Fellas thanks for all the responses. I took a quick look at it after reading these responses. The rubber tubing that connects to both exhaust valves, I believe it's a vacuum assist for the valves, was disconnected to both. I remover cleaning them and being in a hurry to get to dinner, so I must have forgotten to hook them back up. So my sled was running with no exhaust valves. I lifted the rear end and it then hit 8200 rpms. So hopefully it can hit that with me on the sled.
Fellas thanks for all the responses. I took a quick look at it after reading these responses. The rubber tubing that connects to both exhaust valves, I believe it's a vacuum assist for the valves, was disconnected to both. I remover cleaning them and being in a hurry to get to dinner, so I must have forgotten to hook them back up. So my sled was running with no exhaust valves. I lifted the rear end and it then hit 8200 rpms. So hopefully it can hit that with me on the sled.
oh boy, well at least is was just a big "DOH" moment and not a bunch of money..... lesson learned.