Losing RPM... and I want it back!

backcountryislife · Apr 25, 2013

tukernater said:
maybe you could trade primary with one of your buddies and see if it's better?

Funny, coming from Cat I'm used to the primaries being a pain in the A$$... these must be much easier to pull off if you're talking about doing it in the field. I've brought spare secondaries into the field for testing before, but never swapped primaries.

I really need to dig into this sled more, it's kinda fun being on something I can learn about again. Really enjoying trying something new.

tukernater · Apr 25, 2013

backcountryislife said:
Funny, coming from Cat I'm used to the primaries being a pain in the A$$... these must be much easier to pull off if you're talking about doing it in the field. I've brought spare secondaries into the field for testing before, but never swapped primaries.

I really need to dig into this sled more, it's kinda fun being on something I can learn about again. Really enjoying trying something new.

Yep always packing crap up to try stuff pretty easy changing primary's .Have you gave it a good cleaning ?I always clean clutches after 200km and wash my belt in hot water and sunlight.

Beauford t · Apr 25, 2013

I thought the new primarys on the xm were holding up well... guess not

I hate tra's!!
Every second ride I would always grab the movable sheave and look for slop in the bushing and cup, also turn it over by hand slowly making sure all three arms are free with the clicking sounding the same.
The zinc type coating on the arms used too wear/flake off and cause them to bind.

got a 14 on the way so I better get used to fighting primarys again!!

SidewaysInto3rd · Apr 25, 2013

Mine started doing the same thing ... long pulls it would slowly drop RPMs even down to 7300 and it would just get worse

I'd let it sit and cool off a bit and it was good again, I noted that my clutches and belt were not getting too hot

A buddy of mine suggested it's the pipe temp / coolant temp sensor causing the sled to pull timing, maybe a faulty sensor ? maybe it's burning out ? maybe poor timing mapping ? I might try to run a cooler thermostat and see if that fixes the problem, or shim my pipe / can temp sensors

This happened before my "xm problems" thread where it completely died and to this day noone's been able to fix it. So hopefully yours won't suffer the same fate!

One beef I have with the diagnostic process everything always seems to look good at the shop when the sled is running on a stand, but once it's been running for half a day or a long pull things seem to take a turn .. maybe the coils get hot and start to manfunction? maybe the stator? maybe the sensors only malfunction when they get super hot ? who knows ..

I wish dealers would take sleds up for long pulls with BUDS attached and logged the parameters, if such a thing was possible ! I know I would if I had access to the program

Anyway .. I've rebuilt my primary and installed the RB clutch kit, didn't get any long pulls since the sled died again, so if it ever gets fixed i'll see if my long pull rpm fade issue has been resolved by the clutching or if it's an ECU / pipe temp / timing engine issue...

backcountryislife · Apr 25, 2013

tukernater said:
Yep always packing crap up to try stuff pretty easy changing primary's .Have you gave it a good cleaning ?I always clean clutches after 200km and wash my belt in hot water and sunlight.

Well... here in Merika we ain't got no "KM's":face-icon-small-hap... but I suppose after about 400 miles I should clean the thing.

I've never even touched a TRA before aside from adjusting clickers for buddies who didn't know better when they came to ride with me at 12k+ where I used to ride more. I don't even know what the inside looks like. Guess it's time to find out.

winter brew · Apr 25, 2013

To swap clutches, unless you already have the tools, consider using the hydraulic method....real easy in the field, just make sure you have a clutch holder to be able to torque the clutch back on.
Did you try a different belt yet?
Also, with the different track length/RPM relationship....it's not always as it seems. Less track is less load. Secondary being load sensing will allow a shorter track to upshift quicker/farther (all else being equal) which often results in less RPM. But....since this appears to be something significant and sudden, there is likely a cause...it's just a matter of finding and correcting it.

backcountryislife · Apr 25, 2013

winter brew said:
To swap clutches, unless you already have the tools, consider using the hydraulic method....real easy in the field, just make sure you have a clutch holder to be able to torque the clutch back on.
Did you try a different belt yet?
Also, with the different track length/RPM relationship....it's not always as it seems. Less track is less load. Secondary being load sensing will allow a shorter track to upshift quicker/farther (all else being equal) which often results in less RPM. But....since this appears to be something significant and sudden, there is likely a cause...it's just a matter of finding and correcting it.

I'd say significant & sudden would be a stretch... I'm not that far out of break in, and didn't worry much about it before that. when i was at 150 miles I was about 7750ish on a big climb, and bumped the clickers up... it seems like the "drop" got worse after that while the initial rpm improved.

Got two different belts, both do the same thing. Planning on buying a carlisle or gates belt this week as well.

diggerdown · Apr 25, 2013

The little bit I know about the tra's is that all the ones I've ridden with came with solid pins in the clutch and everyone switched them over to hollows and had much better performance. I don't know what the new ones come set up with but at you elevation little things show up big time. Usually by the time you hit 6 on the clickers those things can't get out of their own way. You aren't that big and with the 146 you should be turning real good R's and track speed. We never pulled the clutches to change stuff in them, just took out the center bolt and the clutches came apart.

BackCountryBob · Apr 25, 2013

Everything you ever wanted to know about the TRA, and more.
www.ibackshift.com

BCB

White Rad · Apr 25, 2013

Uhh oh BCIL sounds like the honeymoon is over....next thing you know shes going to start leaving floaters for you to find in the toilet.

Check and make sure the pyros didnt come loose heard of a few working loose and it will throw of fueling

backcountryislife · Apr 26, 2013

Doubt it's a motor issue... until I get in the deeper, long pulls rpm is dead on where I want it.

Still way honeymoon man... I love this sled!! Actually thinking about trading the proclimb in for another one.

Might do that this weekend. I'm just about to do a BDX front end, and prolite post setup... and thought maybe the money would be better spent on a new sled. Watching Abby struggle on the pigclimb is really tough for me... I want sledding to be more fun for her than it is right now, especially with spring riding coming up.

I'll take 300 rpm low... and good handling... any day :cheer2:
300 rpm I can fix without spending 3k Btw, shortened the shocks on the PC to what Brett was running last year for last weekend... it handles way better, but gets stuck SUPER easy. poop.

tukernater · Apr 26, 2013

diggerdown said:
The little bit I know about the tra's is that all the ones I've ridden with came with solid pins in the clutch and everyone switched them over to hollows and had much better performance. I don't know what the new ones come set up with but at you elevation little things show up big time. Usually by the time you hit 6 on the clickers those things can't get out of their own way. You aren't that big and with the 146 you should be turning real good R's and track speed. We never pulled the clutches to change stuff in them, just took out the center bolt and the clutches came apart.

The older clutches up to 06 were splinde and you could remove front of clutch .07 and up they are a taper fit so need to remove whole clutch.I still beleave if you clean the pin in the lower arm you will see a big improvement.I'm thinking sticky arms just can't back shift properly.

backcountryislife · Apr 26, 2013

tukernater said:
The older clutches up to 06 were splinde and you could remove front of clutch .07 and up they are a taper fit so need to remove whole clutch.I still beleave if you clean the pin in the lower arm you will see a big improvement.I'm thinking sticky arms just can't back shift properly.

OK, so I do have to pull the whole primary to adjust it, that's what I thought.

I only do 1/2 days on friday, I'll go out & mess with it in a while.

RKT · Apr 26, 2013

backcountryislife said:
OK, so I do have to pull the whole primary to adjust it, that's what I thought.

I only do 1/2 days on friday, I'll go out & mess with it in a while.

Be careful pulling the clutch, it is "timed" for balance on the crank.. There are 2 circles that show the timing.. 1 circle is the crank timing and hte other is the sheave timing.. They should go back on the same way

backcountryislife · Apr 26, 2013

ok... used to the sheave obviously, but not used to the timing to the crank. Good to know!

SidewaysInto3rd · Apr 26, 2013

pretty sure you don't need to pull the clutch if you are only adjusting weights

undo the bolt and the governor cup should just slide off.. right ? no need for special tools, can do in the field and no need to worry about indexing to the crank. just put the cup back on the same way it came off

make sure to have your forks, otherwise your sliders will fall all over the place, but it's not so bad since they aren't spring loaded you can actually put them back in by hand (if you don't have those forks)

tukernater · Apr 26, 2013

SidewaysInto3rd said:
pretty sure you don't need to pull the clutch if you are only adjusting weights

undo the bolt and the governor cup should just slide off.. right ? no need for special tools, can do in the field and no need to worry about indexing to the crank. just put the cup back on the same way it came off

make sure to have your forks, otherwise your sliders will fall all over the place, but it's not so bad since they aren't spring loaded you can actually put them back in by hand (if you don't have those forks)

Not the 800's there taper fit the 600's are still splinde. cheers

White Rad · Apr 26, 2013

May as well get it over w and get the clutch tools i think you will have fun with a cluth that can actually be serviced! (Not that it needs anything yet but a cleaning)

Another great thing about the doo section is dj and winterbrew are a wealth of clutching knowledge and they love to just help people out and offer advice plus they are straight pros as far as respecting each other and keeping it positive. Listen to them and you will be set!

backcountryislife · Apr 26, 2013

I've been pretty happy with the overall group in the doo section, as long as we don't talk about big bores :tongue:

I think a lot of the guys in the cat section are just frustrated right now, so things get out of hand over there way too often... I feel for them, they must not have your brace on their sleds:face-icon-small-blu

snowmobiler · Apr 26, 2013

a bigbore will fix it

Losing RPM... and I want it back!

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