2012 PRO RMK 800 Problems

[ranger12]

I have a few problems that i was hoping someone could help me out with. I have had this sled for several years and never had a problem with it. It had a BMP fix it kit installed right before i bought it with new cylinders. First time i rode it this year at elevation it ran good except it would only go to 7400 RPMS. I looked everything over and saw oil in the engine compartment and the fitting that goes to the solenoid for the exhaust valves had broke. So i didn't ride it anymore and figured it would be an easy fix at home. Well i installed a new fitting and took it for a ride at home. If i pin it the RPMS will come up to about 7500 and then drop to around 6400. AS long as i don't pin it, say only go to 3/4 throttle it runs strong and will go to at least 8100 before i let off. I have checked about everything on this sled and i cant find anything wrong and it isn't showing any codes or anything. The second problem is my speedometer quit working a while back and while i had the secondary off i messed with the wires for the speed sensor and the speedo is working now but its reading at least twice as much as it should. I am a Cat guy and know about as much as a guy can about them and what to look for but not so much when it comes to these sleds. Is there a way to unhook the TSS and kill switch on these to see if that would eliminate that chance of a problem? TPS problem?

 

[Vincenthdfan]

You may be starving for fuel. How long since the fuel filter was last changed? Do you experience any bogging when you give it a quick burst of throttle?

Also, have you ever got the DET signal/code on the display? A pipe hitting a bulkhead can cause motor to go into DET because it interprets the rattle as engine detonation and pulls timing slowing RPM's.

 

[ranger12]

You may be starving for fuel. How long since the fuel filter was last changed? Do you experience any bogging when you give it a quick burst of throttle?

Also, have you ever got the DET signal/code on the display? A pipe hitting a bulkhead can cause motor to go into DET because it interprets the rattle as engine detonation and pulls timing slowing RPM's.

I replaced the fuel filter about 150 miles ago so i would think its OK ? ? When i had it up in the mountains I could do anything i wanted and it would run 100% normal besides only going to 7400 RPMS. If i held it wide open long enough it would start to stumble a little and drop to 7350 rpms. At home it will occasionally go up to 8350 if i pinned it but most of the time it would only go to about that 7500 and then drop to 6500. It performs normal unless i pin it to the bar. Its has never shown a code. I have actually rode it quite a bit at home after I've checked things and hoped that i found something and watched the dash for rpms or codes and there is nothing. The only thing that is different this year is i put a new battery in it because it was completely dead this fall when i wanted to start it. I planned on unhooking the battery for the summer but didn't get to it.

 

[ranger12]

You may be starving for fuel. How long since the fuel filter was last changed? Do you experience any bogging when you give it a quick burst of throttle?

Also, have you ever got the DET signal/code on the display? A pipe hitting a bulkhead can cause motor to go into DET because it interprets the rattle as engine detonation and pulls timing slowing RPM's.

My first thought was fuel filter also but it just doesn't have that many miles on it. I could have gotten some bad fuel somewhere but wherever this sled got gas my other sleds also got fuel. Maybe the Polaris filter has a finer filter in it than what Cat uses and it could be plugged? I know when i took the old one off i couldn't hardly blow through it and wondered how gas even got through it, but it still ran good. Maybe I will take it off and see how it looks. That is one of the things that has been bugging me.

 

[johnsonracing]

If i pin it the RPMS will come up to about 7500 and then drop to around 6400. AS long as i don't pin it, say only go to 3/4 throttle it runs strong and will go to at least 8100 before i let off.

The very first thing I would do is check the TPS.

 

[ranger12]

The very first thing I would do is check the TPS.

Is there a way to check it without bringing it to a dealer?

 

[johnsonracing]

There are plenty of articles on this forum and videos on YouTube. I use this tool and a multimeter.

Look at this on eBay

Polaris Tps adjustment tool or test pigtail | eBay

Find many great new & used options and get the best deals for Polaris Tps adjustment tool or test pigtail at the best online prices at eBay! Free shipping for many products!

rover.ebay.com

 

[ranger12]

Well I think I have it narrowed down to a fuel pump?? I have gone through everything on this sled and can't find anything wrong anywhere. It has good fuel pressure but i think the pump is fading after a little bit or not enough if i pin it all at once. I plan on hooking up a couple hoses and an amp meter to the voltage supply line and see if the amps start to come up after it runs for a little bit. The Polaris dealer wants like $500 for the whole assembly but a guy told me that i can just get the pump online for like $140. If i ease into the throttle it seems to run normal but if i stab the throttle it will go to 8100 and then drop to 7400 and then to 6500 rpms. If i let off it for a bit and then stab it again most of the time it will usually run the rpms right back up to a normal range for where i'm running it at. Im running it at home now trying to figure this out while its clutched for the mountains. Every once and a while it will surprise me and rev right up to 8300.

 

[ranger12]

Does this look right for the fuel pump that I would need?