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Mach Z Low RPM fix? Change the ramps!?

99K views 818 replies 143 participants last post by  **sj** 
#1 · (Edited by Moderator)
If you read closely you will see the punctuation in my title leaves lots of wiggle room ;)

Everyone knows it by now, most Mach Z's seem to be revving too low. Other models seem to be doing a bit better with some more than others....today I was able to rule out some things.

Most here know the backstory, but I will briefly fill anyone new in.

Dano and I got new 900rs. His Adrenalin and my Mach Z. First real day out riding(lake only) he revs 8000 and settles in at 7900 much of the day on a lake with 8" fluff. My Mach same day only manages to rev 7600 for split second then settles in at 7500. This was a colder day around -15c(5f). At the end of that first day, we both had around 50 miles on ODO. Needless to say, the machine revving correctly would walk the other and have an approx 5mph difference on the top end(GPS). But the RPMs are what this thread is about, not speeds.

Went for a 2nd ride the next day, this was all trail. Pretty much the same thing, adrenalin revving correctly around 7900 and Mach revving at 7500. Now at end of that day, we both have close to 140 miles on ODO.

When swapping sleds as we do often, I could instantly feel the lower engagement, and how much harder it grabs the belt and moves the sled NOW! Mach with that flat section on-ramp comes in 'Soft' and sorta lazy IMO. This feeling continues to about 1/3 throttle. Making the base cheaper ADR feel much more connected to the snow, and also "quicker" down at the bottom.

So I decided to test his 880 ramps on the Mach since all else is equal between these two models. ADR, X, XRS all come with 880 ramps while the Mach comes with 897 ramps. The biggest difference is the flat section at the heel(engagement) which raises engagement rpm to help with Launch Control. Having the quick change ramp tool, and also the Pin removal tool from Chris at C&T Powersports made this ramp change a less than 10 minute job. Got it down to under 60 seconds to pull a ramp. Everyone with a pDrive clutch should own this tool!

Wood Bicycle part Symbol Font Metal



I removed the 880 ramps from Dano's sled, and today installed them into my Mach. I let the sled warm up(but not too hot) to approx 110f. It's a MUCH milder day today then the previous 2 days I rode my Mach stock. Today was -2c(28f) and my lake has some slush in many areas, but not deep slush.

On my road to the lake, I cracked it WOT for a quick shot, unstudded(still) track spun on my hard-packed/icy road instantly hitting 7800. Short road so it was just a quick shot. Enter onto my lake and I have a section approx 2000ft shoreline I like to run. The First 4 runs back and forth, the Mach now revs to 7800 on the hit, then settles to 7700. Far better then the 7500 before(on a colder day). After about 4 runs I saw my temp was now over 180f so I decided to try the Launch Control. LC does still work with the 880 ramps but in a far lesser capacity. It will only hold revs around 3k so not nearly as high and does not hit as hard. So this is why those Mach ramps are needed. As I suspected.

I like the 880 ramps MUCH better overall, from bottom engagement feel(even at 2700) to mid, to top. So I am very happy to have my Dalton adjustable ramps arriving soon from Chris at C&T. The curve on the Daltons will be much closer to the 880 ramps and no flat spot. I could care less about LC and I'm sure I can always raise RPMs with a spring if I really want later. Adjustable will allow me to add/remove tip weight and mid/heel weight to my liking, getting the Mach to rev correctly, and "IF" the RPMs come up by some miracle, I can simply add slugs back into the Daltons at that time. Been running dalton adj weights in most every sled I have owned since the early 2000s, another must-have IMO.

NOTES:
I did check over a few other things today for peace of mind. I removed the IC to check the drain plug on the front bottom corner(chain side) and was able to tighten that finger cap with a T40 Torx about 1/4 turn, but I don't feel it was leaking at all...just was something to check for.(Thanks Phil!)

I also made note of the "play" in the throttle lever. I noted the Adrenalin has far far less play(likely due to no FAR cable routing), while my Mach has a fair bit. So when riding WOT I used my left index finger to press on the exposed cable, taking all the play out til it was taught, and not one single RPM change. So another nonissue.

My takeaway is that Dano's sled while revving higher, was a colder day. And likely today he may have revved a tad less, I'm thinking 7800 rather than 7900. And for mine to rev 7800 and 7700 today with his ramps, I feel my Mach is basically where it should be. In other words, I do not think I have any boost leaks etc. I did go over all clamps and all are tight.(2nd time)

I honestly think BRP designed the 897 ramps all around the launch control and did not pay nearly enough attention to the rest. Studying both these ramps side by side it's plain to see the Mach has more tip weight and less heel weight, and so it's revving lower on top. And the flat section at the heel for LC IMO makes this sled feel very lazy. These will be going in a box as soon as my Daltons arrive.

See video below

Dan

 
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#2 ·
great content as always dan! although i dont have a mach i have been following the rpm struggles many are facing. anything pdrive related is interesting to me and love reading these well put together shared trials.

couldnt agree with you more about the quick change tool from chris. a must have for tuning. big fan of daltons adjustable ramps too (y)(y)
 
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#11 ·
After my Daltons arrive, and I have sled revving right, it will be interesting to see if the RPMS rise as I pile miles on, or will it remain unchanged?

Will be easy to see as I have Danos Adr as test mule.

Next thing will be to dive into the WG crack pressure if the break in achieves no gain in RPMs.

Dan
 
#14 · (Edited)
After my Daltons arrive, and I have sled revving right, it will be interesting to see if the RPMS rise as I pile miles on, or will it remain unchanged?

Will be easy to see as I have Danos Adr as test mule.

Next thing will be to dive into the WG crack pressure if the break in achieves no gain in RPMs.

Dan
Thanks for the RPM update……now what can you tell us about the Smart Shox!!!!! Lol….yes I’m in suspense since my XRS has the dumb shox……..
 
#17 ·
If you read closely you will see the punctuation in my title leaves lots of wiggle room ;)

Everyone knows it by now, most Mach Z's seem to be revving too low. Other models seem to be doing a bit better with some more then others....today i was able to rule out some things.

Most here know the backstory, but I will briefly fill anyone new in.

Dano and I got new 900r's. His Adrenalin and my Mach Z. First real day out riding(lake only) he revs 8000 and settles in at 7900 much of the day on a lake with 8" fluff. My Mach same day only manages to rev 7600 for split second then settles in at 7500. This was a colder day around -15c(5f). At the end of that first day we both had around 50 miles on ODO. Needless to say the machine revving correctly would walk the other, and have an approx 5mph difference on top end(GPS). But the rpms are what this thread is about, not speeds.

Went for a 2nd ride the next day, this was all trail. Pretty much same thing, adrenalin revving correctly around 7900 and Mach revving 7500. Now at end of that day we both have close to 140 miles on ODO.

When swapping sleds as we do often, I could instantly feel the lower engagement, and how much harder it grabs the belt and moves the sled NOW! Mach with that flat section on ramp, comes in 'Soft' and sorta lazy IMO. This feeling continues to about 1/3 throttle. Making the base cheaper ADR feel much more connected to the snow, and also "quicker" down at the bottom.

So I decided to test his 880 ramps on the Mach, since all else is equal between these two models. ADR,X,XRS all come with 880 ramps while the Mach comes with 897 ramps. Biggest difference is the flat section at heel(engagement) which raises engagement rpm to help with Launch Control. Having the quick change ramp tool, and also the Pin removal tool from Chris at C&T Powersports made this ramp change a less than 10 minute job. Got it down to under 60 seconds to pull a ramp. Everyone with a pDrive clutch should own this tool!

View attachment 1986507


I removed the 880 ramps from Dano's sled, and today installed them into my Mach. I let the sled warm up(but not too hot) to approx 110f. It's a MUCH milder day today then the previous 2 days I rode my Mach stock. Today was -2c(28f) and my lake has some slush in many areas, but not deep slush.

On my road to the lake, I cracked it WOT for a quick shot, unstudded(still) track spun on my hard-packed/icy road instantly hitting 7800. Short road so it was just a quick shot. Enter onto my lake and I have a section approx 2000ft shoreline I like to run. First 4 runs back and forth, the Mach now revs to 7800 on the hit, then settles to 7700. Far better then the 7500 before(on a colder day). After about 4 runs I saw my temp was now over 180f so I decided to try the Launch Control. LC does still work with the 880 ramps, but in a far lesser capacity. It will only hold revs around 3k so not nearly as high and does not hit as hard. So this is why those Mach ramps are needed. As I suspected.

I like the 880 ramps MUCH better overall, from bottom engagement feel(even at 2700) to mid, to top. So I am very happy to have my Dalton adjustable ramps arriving soon from Chris at C&T. The curve on the Daltons will be much closer to the 880 ramps and no flat spot. I could care less about LC and Im sure I can always raise rpms with a spring if I really want later. Adjustables will allow me to add/remove tip weight and mid/heel weight to my liking, getting the Mach to rev correctly, and "IF" the rpms come up by some miracle, I can simply add slugs back into the Daltons at that time. Been running dalton adj weights in most every sled I have owned since early 2000s, another must have IMO.

NOTES:
I did check over a few other things today for peace of mind. I removed the IC to check the drain plug on front bottom corner(chain side) and was able to tighten that finger cap with a T40 torx about 1/4 turn, but I don't feel it was leaking at all...just was something to check for.(Thanks Phil!)

I also made note of the "play" in the throttle lever. I noted the Adrenalin has far far less play(likely due to no FAR cable routing), while my Mach has a fair bit. So when riding WOT I used my left index finger to press on the exposed cable, taking all the play out til it was taught, and not one single RPM change. So another non issue.

My takeaway is that Dano's sled while revving higher, was a colder day. And likely today he may have revved a tad less, i'm thinking 7800 rather than 7900. And for mine to rev 7800 and 7700 today with his ramps, I feel my Mach is basically where it should be. In other words, I do not think I have any boost leaks ect. I did go over all clamps and all are tight.(2nd time)

I honestly think BRP designed the 897 ramps all around the launch control, and did not pay nearly enough attention to the rest. Studying both these ramps side by side its plain to see they Mach has more tip weight and less heel weight, and so its revving lower on top. And the flat section at heel for LC IMO makes this sled feel very lazy. These will be going in a box as soon as my Daltons arrive.

See video below

Dan

How come you didn't put the 897s in the other sled and try them so you can get some real feedback
 
#21 ·
I would be ditching the doo primary and secondary springs for Dalton's before adding the Dalton weights. I would also take an 1/8" off that spring cup while I was in there. Run it in same conditions/air temp with spring updates only to see if the results are the same and if they are then throw the weights into the mix..
 
#23 ·
Other than the different ramps , They all left the factory with the same clutches , Unless BRP got a bad batch of springs or a different supplier for the springs. Some Mach’s are pulling 8000/ 7900 all day long. It is definitely got a lot of people taking . Hopefully We get to the root of this issue.
 
#25 ·
Ran my new 900R X yesterday for first time. 1.25 IR, not studded yet, cleaned clutches(scotch brite), tightened belt and track. Rode it easy for first 30 miles to break in belt and sliders. First time I wacked it WOT I see 8000 and holds at 7900. That was at around 50 miles on sled. Every time afterward I pinned it same thing, 8000 then hold at 7900. Never held it WOT for more than 5 seconds or so and recorded 117 on the dream-o-meter.
 
#33 ·
One variable in everyone's overall RPM readings may be that the tach functions are not all 100% the same accuracy... +/-100 RPM difference would not surprise me across a broad population of sleds, even with the digital computers doing the tach function. We're not buying calibrated tachs with these machines.

BTW OP, do you recall the exact top end GPS speeds (that were 5 mph different) on that first day? If the speed difference of 5 mph was in proportion to the 400 RPM difference, it would work out to 94 vs 99 mph.
If different from those speed numbers, then the matters of belt slippage and tach differences become variables. It might be worthwhile checking the sheave temps on the 2 machines after running them hard for a while.
 
#36 ·
If you read closely you will see the punctuation in my title leaves lots of wiggle room ;)

Everyone knows it by now, most Mach Z's seem to be revving too low. Other models seem to be doing a bit better with some more then others....today i was able to rule out some things.

Most here know the backstory, but I will briefly fill anyone new in.

Dano and I got new 900r's. His Adrenalin and my Mach Z. First real day out riding(lake only) he revs 8000 and settles in at 7900 much of the day on a lake with 8" fluff. My Mach same day only manages to rev 7600 for split second then settles in at 7500. This was a colder day around -15c(5f). At the end of that first day we both had around 50 miles on ODO. Needless to say the machine revving correctly would walk the other, and have an approx 5mph difference on top end(GPS). But the rpms are what this thread is about, not speeds.

Went for a 2nd ride the next day, this was all trail. Pretty much same thing, adrenalin revving correctly around 7900 and Mach revving 7500. Now at end of that day we both have close to 140 miles on ODO.

When swapping sleds as we do often, I could instantly feel the lower engagement, and how much harder it grabs the belt and moves the sled NOW! Mach with that flat section on ramp, comes in 'Soft' and sorta lazy IMO. This feeling continues to about 1/3 throttle. Making the base cheaper ADR feel much more connected to the snow, and also "quicker" down at the bottom.

So I decided to test his 880 ramps on the Mach, since all else is equal between these two models. ADR,X,XRS all come with 880 ramps while the Mach comes with 897 ramps. Biggest difference is the flat section at heel(engagement) which raises engagement rpm to help with Launch Control. Having the quick change ramp tool, and also the Pin removal tool from Chris at C&T Powersports made this ramp change a less than 10 minute job. Got it down to under 60 seconds to pull a ramp. Everyone with a pDrive clutch should own this tool!

View attachment 1986507


I removed the 880 ramps from Dano's sled, and today installed them into my Mach. I let the sled warm up(but not too hot) to approx 110f. It's a MUCH milder day today then the previous 2 days I rode my Mach stock. Today was -2c(28f) and my lake has some slush in many areas, but not deep slush.

On my road to the lake, I cracked it WOT for a quick shot, unstudded(still) track spun on my hard-packed/icy road instantly hitting 7800. Short road so it was just a quick shot. Enter onto my lake and I have a section approx 2000ft shoreline I like to run. First 4 runs back and forth, the Mach now revs to 7800 on the hit, then settles to 7700. Far better then the 7500 before(on a colder day). After about 4 runs I saw my temp was now over 180f so I decided to try the Launch Control. LC does still work with the 880 ramps, but in a far lesser capacity. It will only hold revs around 3k so not nearly as high and does not hit as hard. So this is why those Mach ramps are needed. As I suspected.

I like the 880 ramps MUCH better overall, from bottom engagement feel(even at 2700) to mid, to top. So I am very happy to have my Dalton adjustable ramps arriving soon from Chris at C&T. The curve on the Daltons will be much closer to the 880 ramps and no flat spot. I could care less about LC and Im sure I can always raise rpms with a spring if I really want later. Adjustables will allow me to add/remove tip weight and mid/heel weight to my liking, getting the Mach to rev correctly, and "IF" the rpms come up by some miracle, I can simply add slugs back into the Daltons at that time. Been running dalton adj weights in most every sled I have owned since early 2000s, another must have IMO.

NOTES:
I did check over a few other things today for peace of mind. I removed the IC to check the drain plug on front bottom corner(chain side) and was able to tighten that finger cap with a T40 torx about 1/4 turn, but I don't feel it was leaking at all...just was something to check for.(Thanks Phil!)

I also made note of the "play" in the throttle lever. I noted the Adrenalin has far far less play(likely due to no FAR cable routing), while my Mach has a fair bit. So when riding WOT I used my left index finger to press on the exposed cable, taking all the play out til it was taught, and not one single RPM change. So another non issue.

My takeaway is that Dano's sled while revving higher, was a colder day. And likely today he may have revved a tad less, i'm thinking 7800 rather than 7900. And for mine to rev 7800 and 7700 today with his ramps, I feel my Mach is basically where it should be. In other words, I do not think I have any boost leaks ect. I did go over all clamps and all are tight.(2nd time)

I honestly think BRP designed the 897 ramps all around the launch control, and did not pay nearly enough attention to the rest. Studying both these ramps side by side its plain to see they Mach has more tip weight and less heel weight, and so its revving lower on top. And the flat section at heel for LC IMO makes this sled feel very lazy. These will be going in a box as soon as my Daltons arrive.

See video below

Dan

Hey Dan, is there anywhere in Ontario to purchase these tools for the privet?? I'm located in muskoka area. This tool looks pretty slick! Thanks for all your research and posts on Dootalk & totally Yamaha 👍 great stuff!
 
#42 · (Edited)
the quick change tool was originally made by Goodwin
any real goodwin seller should have them us$80
goodwin also sells the clicker weight set for 900
 
#51 ·
Not sure if Goodwin is a DT sponsor?
And I would personally never use clickers for the 900r.

I do know Chris at C&T has been a long time DT sponsor and has set me up with anything I order, be it when I'm in NY or here in Muskoka Canada, he gets my email request and replies right away and things get to me fast.

Dan
 
#54 ·
the Grip N Rip Racing Products pdrive alignment tool is complex and seems to work sweet
mine only needed one shim behind the bearing. their video helps understand how to use it
 
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#55 ·
Thats not really Chris tool, that is the Goodwin tool that Chris sells I assume. I would be interested in a higher finish, Gboost belt and grind a little weight off the tip. Thanks for sharing.
 
#57 ·
I don't think it is a ramp issue on the Mach. My 00006 serial number Mach pulls 7900, pulls hard out of the hole or a role on and or using launch out of the hole. 95mph on dragy in 660. All the aforentioned data was with 3 miles on the clock so not a break in issue either. Very simular performance to my old stage 2 PEFI sled.

Do your diligence to ensure no boost leaks and ensure belt deflection is tight and not the loose nonsense they recommend in the manual to ensure no issues with electronic reverse engagement. Other than that, keep in mind BRP has many layers of safeties in the ecu for intake Temps etc etc that can pull power and drag down rpm so if your doing repeated wot runs or extended runs or driving in mild conditions your rpm will be down because of heat soak etc. These 900's are the most sensitive sled I have ever owned with regards to ambient temp and heat soak fast at WOT.

Hope this helps...

BJK
 
#96 ·
Disagree....MUCH of this is the Mach ramps. Driving these two sleds back to back its instantly felt. I do not like the Mach ramps at all.

Now that being said, the top end RPMS are still lower on one sled then the other(with same ramps installed) but are much closer within 150rpms or so. That is a lot closer than 400+ rpms difference and may be attributed to the single ply track vs 2 ply. As a matter of fact, In my conversations last spring with rep at shows, all the test mule Machs had single ply tracks, could that be why the rpms are off? Did those test mules rev correctly due to having single ply LIGHTER tracks? Dont know but it certainly is plausible.

I'm actually a lot less concerned that their is a boost leak/issue now. Yesterday I was running my lake and seeing much better speeds even while under revving. And I think once I have this thing clutched with my setup it will be right where it should be.

IMO the Mach Z ramps are a total miss. Guys may disagree but you have likely not slapped another set of ramps in you Mach yet to compare the hard hit of the NON FLAT SPOT ramp. I will take a hard bottom pulling sled every time over the Launch control which is simply a gimmick that I really do not need.

Daltons arriving today with Chris's super fast shipping from his place in NE USA to me in Muskoka Ontario exactly 1 week. Thanks again Chris for getting them out to me.

Dan
 
#64 ·
IMO they are quite complex for weights
and with the big torque range of 900r
not really needed...once the adjustable weights are set
they really dont need any adjustments
the two strokes have a narrow torque rpm range
and trail conditions make a bigger difference for them
 
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