Pro RMK not Pulling RPMs

[Hillclimber81]

I'm running a new to me 13 pro RMK. Been having issues with it reaching peak RPM, since I've owned it, it's never pulled tach higher than 8000. Today it at 8000 ft with 10-60 weights it would only pull 7450-7500 rpm. I noticed that there was a check engine light on stating 173-3 or high voltage exhaust temp sensor. Could this be keeping me from. Holding tach where I am supposed to be? I'm pretty lost, I haven't checked my secondary spring or anything inside the secondary yet, but everything in the primary looks great. I hate missing out on the peak horsepower because it makes riding super difficult. Any help is appreciated.

 

[cascadesnowjunky]

Yes 173-3 is pipe temp sensor failure and it will limit rpm until you replace it.

 

[Hillclimber81]

Yes 173-3 is pipe temp sensor failure and it will limit rpm until you replace it. View attachment 335950

Would it limit is by as much as 700-800 rpm?

 

[cascadesnowjunky]

Yes normally it wont rev past 6500 - 6800. I just replaced one on my 17 axys last year and I had to replace a couple on my 11 pro. When mine went out last year it pulled rpm a couple times just randomly on the way back to the truck but when they go they basically are stuck in limp mode.

 

[cascadesnowjunky]

If you have a check engine light that is on and says 173-3 you may as well just go buy a new pipe temp sensor because there is no other way around it. They are not cheap but that is the issue.

 

[Hillclimber81]

Alright I wouldn't have thought the pipe sensor would cause that big of a limo mode but it's worth a shot needs replaced anyways

 

[cascadesnowjunky]

The reason is that sensor has a huge roll in the fueling, they did it to keep from burning it down. It needs that perameter to adjust the fuel supply to the engine.

 

[Hillclimber81]

Are there any known options other than stock, for replacement?

 

[sledtahoe]

Does the light stay on? mine would come on going down hill but go off once i pinned it wide open. Now if you getting to 7500 its not in limp mode belt deflection is important. Mine rarly goes much over 8k but when hit powerband it will hold solid. Its sounds like you need to buy a exhaust sensor anyway. have you cleaned the powervalves, if not opening all the way is a issue.

 

[Hillclimber81]

Does the light stay on? mine would come on going down hill but go off once i pinned it wide open. Now if you getting to 7500 its not in limp mode belt deflection is important. Mine rarly goes much over 8k but when hit powerband it will hold solid. Its sounds like you need to buy a exhaust sensor anyway. have you cleaned the powervalves, if not opening all the way is a issue.

Have cleaned powervalves, and light does stay on. I'm sure there is more to it than just the sensor, but it can't be helping matters.I only occasionally got 7500, most of the time it was much closer to 6800-7200. I rode it the entire day and the light was on the entire time.

 

[Hillclimber81]

Does the light stay on? mine would come on going down hill but go off once i pinned it wide open. Now if you getting to 7500 its not in limp mode belt deflection is important. Mine rarly goes much over 8k but when hit powerband it will hold solid. Its sounds like you need to buy a exhaust sensor anyway. have you cleaned the powervalves, if not opening all the way is a issue.

Also belt deflection is perfect

 

[sledtahoe]

yep better get the exhaust sensor for starters

 

[Hillclimber81]

yep better get the exhaust sensor for starters

Just wish the new ones weren't so bloody expensive. Gonna have to wait until after the holidays to purchase a new one. I've thought about picking up a used one somwhere, but then risk the same thing happening again.

 

[hamlin]

Look on eBay if you want used, but like you said, what if the used one only lasts a month

 

[sledtahoe]

i've had good luck with a used one but its a risk.

 

[Hillclimber81]

Pulled my Reed cages out and the petals are starting to chip and flake. Is it possible to get new petals? And if so which brand should I get? I would like to about getting a fuel controller, but will if needed. What is best vs most inexpensive option?

 

[SRXSRULE]

You can test your EGT sensor. Here is the specs
Sensor Specifications
Resistance
Values
2.3M ohms @ 392_F (200_C)
76 ohms @ 1652_F (900_C)

If you need a new one, SPI does make one. its about 1/2 price. https://www.ebay.com/p/5027482664?i...MI3OLxq4m05gIVw8DACh2i-wC1EAQYASABEgLu2fD_BwE

 

[Hillclimber81]

You can test your EGT sensor. Here is the specs
Sensor Specifications
Resistance
Values
2.3M ohms @ 392_F (200_C)
76 ohms @ 1652_F (900_C)

If you need a new one, SPI does make one. its about 1/2 price. https://www.ebay.com/p/5027482664?i...MI3OLxq4m05gIVw8DACh2i-wC1EAQYASABEgLu2fD_BwE

Thanks is for the info I'll give it a test!! That makes things easier for sure. And the SPI one will probably be what I get. Any suggestions on new reeds?

 

[SRXSRULE]

Thanks is for the info I'll give it a test!! That makes things easier for sure. And the SPI one will probably be what I get. Any suggestions on new reeds?

I only use Polaris reeds in these engines. V-force reeds tend to cause idle problems in these years of Pros. How bad are they? some small chips are normal. Are the reed petals still covering all of the opening in the reed block? If they are, they still have some life left in them. You can also take them apart and flip the petals over if they are not sealing tight up against the block.

 

[Hillclimber81]

I only use Polaris reeds in these engines. V-force reeds tend to cause idle problems in these years of Pros. How bad are they? some small chips are normal. Are the reed petals still covering all of the opening in the reed block? If they are, they still have some life left in them. You can also take them apart and flip the petals over if they are not sealing tight up against the block.

They are only mildly chipping, nothing major, just don't want them to completely break and destroy the motor. I'll attach pics. I'm also getting 5.045vdc as the input voltage to my TPS when I try and reset it, with two different fluke 88 meters. Leading me to believe I may have voltage regulator issues.