2005 M7 162 70mph top speed

canyoncat · Dec 18, 2007

Just wondering what you guys with M7's are seeing for top speed. I'm running this clutch set up 70gram cats with gold cat spring in primary, 44/40 helix with cat orange spring, shift assist, rkt head 14.1. Was at 5000' flat air strip 2" of pow, xs belt about 7700rpms

mrquick68 · Dec 18, 2007

somethings not right. You should be able to pull more speed than that. Is your M8 spring backed out all the way? It should be...

canyoncat · Dec 18, 2007

yes spring is backed all the way out. also should mention I used a slp spider shim kit to set belt to sheave clearance would this affect anything

mrquick68 · Dec 18, 2007

wondering if you are running too much compression. i know you said you were running at an air strip at 5000ft, where is one of those in WA? The only strip i know near Wenatchee is at Lake Wenatchee and that strip is only 2000ft. Just wondering. 14:1 is pretty high for here...

canyoncat · Dec 18, 2007

emergency air strip jump off ridge road south of wenatchee

mtn_extreme · Dec 19, 2007

Did you machine out your primary clutch spring seats. Could be getting spring bind and not getting full shift out. I really don't think your too far off with the xs belt. What pipe and should the rpm's be slightly higher?

mtn_extreme · Dec 19, 2007

44/40 is plenty of helix also. I run a bb m8 with a finish rate of 38*

DonoBBD · Dec 19, 2007

mtn_extreme said:
44/40 is plenty of helix also. I run a bb m8 with a finish rate of 38*

I agree. What elevation? If the spider spring cup is fine then drop in goodwin Dark blue/yellow with the 44/40 helix. The 70 gram weight have me thinking your at 3000-6000 feet. IF your running the shift assist the top end can fall on her face.... RPM's drop 300. Going up 35-50# average on the spring rate will pic that up.

If some one has done a weight change check for one or more of the weights slid over. IN this picture you can see these two edges. The weight can catch in this small pocket and stop the shift.

furthur · Dec 19, 2007

If your pulling 7700 RPM, it's not hanging up...it's shifting (if it weren't shifting, or the belt was slipping, it would be over-reving). Sounds like your not making the power on top end...is your track tension/ski alignment/belt alignment/DD oil ok? Do you have a big air horn/intake mod's on it? What can and pipe? Have your checked the plugs or wash? You might drop a couple of grams from the primary weights, or screw the secondary adjuster in a bit, to see if another 100-200 rpms makes a diff, your RPM is a little low, but not bad.

ICLIMB · Dec 19, 2007

What symptoms would you see with the Big air horn/intake? What would cause it? Less air velocity?

DonoBBD · Dec 19, 2007

furthur said:
If your pulling 7700 RPM, it's not hanging up...it's shifting (if it weren't shifting, or the belt was slipping, it would be over-reving). Sounds like your not making the power on top end...is your track tension/ski alignment/belt alignment/DD oil ok? Do you have a big air horn/intake mod's on it? What can and pipe? Have your checked the plugs or wash? You might drop a couple of grams from the primary weights, or screw the secondary adjuster in a bit, to see if another 100-200 rpms makes a diff, your RPM is a little low, but not bad.

Further the orange spring and shift assist will over shift. Your mid will hit 8000 then drop to 7700. The easy fix is goodwins Blue/yellow spring 215/335.

canyoncat · Dec 19, 2007

DonoBBD said:
Further the orange spring and shift assist will over shift. Your mid will hit 8000 then drop to 7700. The easy fix is goodwins Blue/yellow spring 215/335.

don do you mean the 235/335 dk blue/ yellow, I don't see a 215/ 335 blue/ yellow listed on goodwins site

mrquick68 · Dec 19, 2007

DonoBBD said:
Further the orange spring and shift assist will over shift. Your mid will hit 8000 then drop to 7700. The easy fix is goodwins Blue/yellow spring 215/335.

Dono - you know your clutching better than me, but man, that's one SUPER stiff secondary spring... I'd think you'd swing your rpms way to high too fast with that stiff of a starting rate on that spring with a 44/40? And wouldn't your backshift be WAY too fast with that stiff of a spring and a steeper helix?

Also - why do think orange would allow an over shift with a 44/40? That's basically what all M8s and m1000s come stock with here in WA for 3000 to 6000ft and the ones i've ridden definitely don't overshift like that. If you were hitting 8000 and falling back to 7700 i'd say you weren't getting belt grip in the secondary if that was the case. But a 44/40 should allow grip especially with the sticky XS belt...

Just my out loud thoughts, but he's not over revving but he isn't getting track speed. Sounds like he is either missing the power to pull the speed any higher or he has too much load coming from somewhere else...

Shake&Bake · Dec 19, 2007

I ride 2000-5000' and have an 05 M7 162 with the Orange M8 Secondary spring and D&D shift Assist, and 70g weights with an AC Gold primary spring. At 2200' in 2' of powder my RPM's top out at 8020, but in the hills around 3500-4000' I am running 7800-7900 range. In 2-3 feet of powder my top speed has never been better than around 55 MPH, 60 if i was lucky.

My speedo quit so i have to count on other sleds clocking me. All I have is a tach. But even with stock clutching or this new setup, i dont believe I have seen over 55 MPH ever in 2-3 feet of pow on a flat run.

DonoBBD · Dec 19, 2007

canyoncat said:
don do you mean the 235/335 dk blue/ yellow, I don't see a 215/ 335 blue/ yellow listed on goodwins site

Yes talk to goodwin the rate posted are not what they are in the cat clutch. 2.9 she is 200ish not much more then the orange spring. At 1.6 she is 330ish.

mrquick68 said:
Dono - you know your clutching better than me, but man, that's one SUPER stiff secondary spring... I'd think you'd swing your rpms way to high too fast with that stiff of a starting rate on that spring with a 44/40? And wouldn't your backshift be WAY too fast with that stiff of a spring and a steeper helix?

Also - why do think orange would allow an over shift with a 44/40? That's basically what all M8s and m1000s come stock with here in WA for 3000 to 6000ft and the ones i've ridden definitely don't overshift like that. If you were hitting 8000 and falling back to 7700 i'd say you weren't getting belt grip in the secondary if that was the case. But a 44/40 should allow grip especially with the sticky XS belt...

Just my out loud thoughts, but he's not over revving but he isn't getting track speed. Sounds like he is either missing the power to pull the speed any higher or he has too much load coming from somewhere else...

Trust me all 05-06 type helix's are loosing RPM with the orange spring and shift assist. IF your not using the shift assist your fine the spring bind in the secondary holds more pressure taking two coils out of the shift.

Tell you what. Get a valve spring tester. One for cars and trucks. Rig it up in a drill press and put your secondary into the drill press. Shift it out and get a reading of pressure. Then put in a shift assist and do it again. See how much lower your pressure is. 35-50#'s less over all.

So to keep the RPM's they turn in the orange spring .375"s but then you over rev down low. The spring is to short. There is a ton of flat landers that are finding this. Goodwins Dark blue is a perfect replacement too.

The XS belt will pull 200-300rpm's off just because it is so sticky.

Canyoncat Is the sled hitting 8000-8050 then dropping?

AaronBND · Dec 19, 2007

Shake&Bake said:
I ride 2000-5000' and have an 05 M7 162 with the Orange M8 Secondary spring and D&D shift Assist, and 70g weights with an AC Gold primary spring. At 2200' in 2' of powder my RPM's top out at 8020, but in the hills around 3500-4000' I am running 7800-7900 range. In 2-3 feet of powder my top speed has never been better than around 55 MPH, 60 if i was lucky.

My speedo quit so i have to count on other sleds clocking me. All I have is a tach. But even with stock clutching or this new setup, i dont believe I have seen over 55 MPH ever in 2-3 feet of pow on a flat run.

I have this exact same setup except with 70g weights and am only pulling 7400rpm's at around 6-8K. Been messing with the clutching with no results, and am wondering if it's power valves out of adjustment or something totally different than clutching. I don't have any 68's to try in it, but was thinking about throwing in my old 65's just to see if it revs higher or if it is another problem.

Aaron

mtn_extreme · Dec 19, 2007

"My speedo quit so i have to count on other sleds clocking me. All I have is a tach. But even with stock clutching or this new setup, i dont believe I have seen over 55 MPH ever in 2-3 feet of pow on a flat run."

There is a BIG difference between 2 INCHES and 2 FEET of powder. 55 mph in 2 feet is pretty good in my book.

mtn_extreme · Dec 19, 2007

"So to keep the RPM's they turn in the orange spring .375"s but then you over rev down low. The spring is to short. There is a ton of flat landers that are finding this. Goodwins Dark blue is a perfect replacement too."

I can somewhat agree with this, so with the higher rates on the goodwin does it slow down your backshift any?

MTm7 · Dec 19, 2007

great... so now i need a differnt spring before i even really get to test this one!!!

winter brew · Dec 19, 2007

I found that orange spring to be just to much. I know every sled, conditions and rider preference will be a bit different, and there is more than one way to get results. I had 75-77g weights on my ET900 and a 162 track,and found GREAT backshift with a 36 and a mild spring (160/240 Team). Remember that it's the helix and not the spring that tackles most of the backshift force. Too much spring just keeps the helix from being about to do it's job IMHO.
Also, a 44/40 is too steep for a 162 in the hills. Fine for shorter tracks, but a 36 is pretty much mandatory with a 162 if it's used in the steep/deep.
With a shallower helix there is no need for huge spring pressure in the secondary.
I think the problem stated by the originator of this thread is a combination of the 44/40 and the XS belt holding down RPM. Put in a 36, a softer secondary spring, and a stock belt and you will see 90.
Also make sure the rollers are in good shape, any sign of flat spots and they cause problems.

2005 M7 162 70mph top speed

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