Overreaching m800 help!!

[nadrojcote]

Ok... I have a 2012 M800 all stock motor, y pipe and pipe. With an mbrp can.

I live in Manitoba where elevation is 400m.

My clutching setup is as follows.

Team primary
-Lime green SSI 100/250 spring
-SSI adjustable weights maxed out at 86g

Stock secondary (non team style)
-Stock black/blue spring 284lb
-42/40 low elevation arctic cat helix
-Rebuilt with new rollers and bearings

I've used an arctic cat 084, Carlisle ultimate and a Dayco XTX belt. They all perform approx the same. Belt deflection is set properly.

My issue is that I'm hitting over 8300rpm even with the weights maxed out. From everything I'm reading and after reaching out to BDX via email I should not be revving this high. They say I should be using about 76-77g of weight.

What am I missing here? Something doesn't seem right.

 

[kiliki]

Check the primary rollers for worn bushings and flat spots also check the spider for cracks at the base of the spring.

 

[xpturbo600]

Throw more weight in it or take some spring pressure out of it to see what it does. Something is stalling the shift either in the secondary or the primary. In the secondary, try putting more helix angle in or less spring pressure. Alternatively in the primary put more tip weight or soften the spring a hair. If it is a fine tune target, use weights or helix.

This all assumes the inner working components are good. They may have sent you the wrong kit for your very low elevation. Because they say you shouldn't make rpm doesn't mean they are right. It depends on what elevation the clutch kit is tuned for. It isn't one si,e fits all. If they got you most of the way. Try making a few minor changes to adjust for the fact you may be simply making more power.

Step one, pick a softer primary spring sub 250 but higher than 200 that maintains a similar ratio of the lower spring value divided by the upper spring value. That will help maintain the current level of rpm engagement from a stop. Then, retry. If that isn't enough, put a bigger helix in it. To be honest a 40/42 looks like a high elevation helix. Put something like a 44/46 in it. That should give you enough range in combination or individually to tune the weight and get where you need to be. Again, assuming nothing is broken internally that is stalling the shift.

 

[kiliki]

Agreed the secondary helix should be 44 to 46 this will drop the rpm about 300. And get you moving out of the hole!

 

[Old & slow]

You may want to confirm the tach is accurate, also is this a new problem. Have you owned the sled for a long time or did you just buy it. The more information you can give the more complete answer you will get.

 

[nadrojcote]

I've owned it for two years. It wasn't a problem until I upgraded to a team primary and I've been trying to figure out the weight/spring combo since.

The clutches are clean and in good condition. I'm wondering if it's just an issue with how the team primary interacts with a non team secondary.

The 42/40 helix is the arctic cat recommended low elevation helix for this snowmobile.

I can't add more weight. Since the weights are maxed out my engagement rpm is really low around 3000 rpm. It's just the max rpm that's high. And the tach seems accurate since it was fine with the old primary and it screams when I'm revving it.

I can remove a bit of spring weight by getting a cat spring instead of the SSI spring. The odd thing is that cat recommends at 72g weight and 255lb spring for low elevation for the team primary.

Arctic Cat Low Altitude Clutch Kit - 0-3000ft - 2017 M 8000

Arctic Cat Low Altitude Clutch Kit - 0-3000ft - 2017 M 8000 - 7639-664

www.countrycat.com

I forgot to add that I have changed the 2012 gearing from 21/49 to the 13+ 19/50 gearing.

 

[spoon]

Gearing might be part of issue as well as a secondary issue. Does anyone you ride with have similar sled? Try swapping secondaries on the trail and see if issue is same or changes at all. Any sign of belt slippage in either clutch like rubber smears? Does sled have stock drivers or are you running bigger track with 7 tooth? I was running 70gr with that spring at 7000 ft on team roller primary on my 13. Is your primary the 18+ roller or 16-17 non?

 

[greenmtnboys]

Gearing defiantly will gain you rpm the motor is not working so hard to turn the track. I did that to mine,I just added some weight to the front clutch and it pulled hard. I purchased the Dalton adjustable weights easy to adjust and work great.

 

[Old & slow]

The RPM specs are 81-82 so you are within 100-150 and that isn't to bad. Changing the gearing or the helix will bring the RPM down most likely to where you will need to remove primary weight.

 

[nadrojcote]

Gearing might be part of issue as well as a secondary issue. Does anyone you ride with have similar sled? Try swapping secondaries on the trail and see if issue is same or changes at all. Any sign of belt slippage in either clutch like rubber smears? Does sled have stock drivers or are you running bigger track with 7 tooth? I was running 70gr with that spring at 7000 ft on team roller primary on my 13. Is your primary the 18+ roller or 16-17 non?

Unfortunately every one I ride with is on doo's and poo's.

I went out for a ride yesterday and paid attention to my rpm while riding and I was actually only hitting about 8100, I was using the max rpm feature on the gauge before and it must have been only hitting over 8300 for tiny short amount of time.


Clutches are in great shape and no signs of belt slipping.

I'm going to run it like this for now. I'm heading to West Yellowstone in a week. I'll play around there and see what it wants for cam arm weight to really compare to other sleds. It's hard to use what others are running as a baseline cause everyone seems to ride at higher elevation than me.

I do want to add that I think I found a solution to the intermittent bog off the line that a lot of people have with these sleds. I've had my TSS disabled and the air sensor relocated and my problem seemed to be mostly fixed, but I still had a stalling out every now and then when taking off if I didn't blip the throttle first. When I swapped to my 36 helix in preparation for my trip next week I noticed the bog got significantly worse and was happening almost every time. This lead me to believe the issue was caused by the helix/secondary. I pulled it apart again and found the rollers had left a notch in the ramps where they first contact. I used a bench grinder and some emery cloth to smooth out the ramps and slapped it back together. At the same time I took one weight out of the heel of each cam arm. Went for a quick ride around the field out back and the problem seems to be resolved. I need to go for a longer ride to know for sure, but I assume the issue is from the combination of low rpm clutch engagement combined with a worn helix. At low RPM the Suzuki doesn't have the power to get unstuck out of that groove in the helix.

 

[nadrojcote]

Also would like to add the title of this thread was supposed to be Overrevving not Overreaching. Auto correct on my phone changed it and I don't know how to edit the original post to correct it.

 

[sno*jet]

Throw their (SSI) y-pipe on it. changes the big power dropoff they have when over-revving as well as adds a little low grunt. HP should be about the same 8000-8300rpms IIRC their dyno chart.
Also check your reeds for chips.