Not getting enough RPMs

[Iceman56]

2013 Pro 163, at 10,000 ft (Laramie, Wy) I am only pulling about 7900 to 8000 rpm with 1058 weights??? It will actually very between 7800 to 8100 depending on how it will backshift the backshift also feels sluggish and not crisps like it used to. It just started doing this the last two trips, before that I had it in west Yellowstone (8,000ft) with 1060's and it ran flawless great backshift pulling 82-8300 rpm. I've had it out to Tog and Cooke before this too and ran awesome. My buddies same exact sled was out there with me this wkd with 1060 weights pulling 82-8300...
I have tried two different belts, adjusted belt in secondary, primary spring looks good. Anyone have any suggestions on what went wrong with this thing??? Or anything to try or check??

Thanks for any help

 

[Iceman56]

Ttt

 

[Scary Larry]

I think its probs your radiator

 

[660 assault]

Do you have black purple secondary spring in it? Maybe 10-58 are too light ,
not loading motor

 

[Iceman56]

I think its probs your radiator

Yeah that or the glow plugs

 

[Iceman56]

Do you have black purple secondary spring in it? Maybe 10-58 are too light ,
not loading motor

Not sure whatever came from factory... If it wasn't loading the motor wouldn't it just over rev??

 

[AdrenalineAddict]

Give your primary spring a good look, they break quite often. As the motor mounts wear a bit you may get what I call "long belt syndrome" lack of RPM's and poor backshift requring the purple black secondary spring. You may also want to pull your mag. side powervalve (easiest) and give your piston an inspection, I believe running on the premium setting with low octane gas will detonate and destroy these motors long before you ever get a DET code.

 

[Iceman56]

Give your primary spring a good look, they break quite often. As the motor mounts wear a bit you may get what I call "long belt syndrome" lack of RPM's and poor backshift requring the purple black secondary spring. You may also want to pull your mag. side powervalve (easiest) and give your piston an inspection, I believe running on the premium setting with low octane gas will detonate and destroy these motors long before you ever get a DET code.

haha that scares me I actually hit my DET on a really long pull the the last ride before this started happening.

Good to know about the motor mounts I will give that secondary spring a try

 

[JonezyBones]

How many miles? Eth or non ethanol fuel? How many miles are on your belt? Any mods?

 

[Iceman56]

How many miles? Eth or non ethanol fuel? How many miles are on your belt? Any mods?

700 miles now... 91 from the pump... belt has been changed out two times to try and fix the problem but didn't help any... Everything is stock

 

[JonezyBones]

Try looking through your secondary as well. It could be opening prematurely causing too much of a load on your engine. Any black marks on your clutches? Definity check for piston scuff. Also have you cleaned your power-valves lately? Good luck!

 

[14eer]

I second the primary spring. Mine acted very similar....spring broke at the end... could not see it until cover was pulled. But it never hurts to throw a compression tester on.

 

[Condog]

vfc

 

[Scary Larry]

I bet its your snow flap thats causing loss of rpms

 

[660 assault]

Haha, get a life clown

 

[660 assault]

Stock is black 155-220, black purple is 160-240 and recommended above 8000 ft

 

[Iceman56]

Try looking through your secondary as well. It could be opening prematurely causing too much of a load on your engine. Any black marks on your clutches? Definity check for piston scuff. Also have you cleaned your power-valves lately? Good luck!

What should I be looking for when looking through the secondary? I don't think there is any black marks I will look today for sure... No have never cleaned power valves. Do they need to be cleaned after 700 miles?

 

[RMK935VA]

I can't help much but I also have a 2013 163 with the Carl's Clutching Kit. I hold 8300 - 8400 RPM in all snow under load. It also backshifts like a dream. Their kit includes helix, springs, belly buster weights and you can also have them machine the clutch faces for a little added extra. My sled clutches perfectly and the clutches run much cooler than the stock setup. It is not an expensive mod and it really works!

 

[JonezyBones]

What should I be looking for when looking through the secondary? I don't think there is any black marks I will look today for sure... No have never cleaned power valves. Do they need to be cleaned after 700 miles?

In your case it could be the spring in the secondary. Doubtful that its worn out but its ease of mind. And yes your power-valves could use a cleaning after the first 500 miles. They can get pretty gummed up and not open all the way causing you to loose top end rpm. Check the spring in the power-valves and the rubber bellows for holes. And just clean all the carbon deposits and should be good to go.

I cleaned mine after 600 miles and they were caked up with carbon. They slide much better now.

 

[FatDogX]

I would agree with everyone above about checking clutches and power valves but there is also one other thing to check / change that is going to sound crazy.

I have two buddies that had the exact same issues your describing. Clutches were checked / cleaned as well as the power valves. Everything was clean and good to go and it still did what your talking about.

They were told to put a new set of plugs in and see what happens. Low and behold after a new set of plugs, no issues, problem solved.

Like I said, I know it sounds a little strange but it worked.