2007 M8 Clutching Help

[trackvs2wheels]

Hey guys,

I have searched using the stinky "search" button but cannot find the specific information I am after...

Have an 07 M8 and we run at 10k feet all day long. This sled is the 162" efi model if that matters. I am wondering what clutching setup I should be after to make this sled run the correct r's that it needs????

Right now the sled is set up with 68 gram weights which I beleive to be too heavy. On the trail it sort of feels like an 800 under the hood, but in the deep it literally feels like a little M5 or something under the hood

ANY help and/or advice would be greatly appreciated. I am helping a buddy trying to get this sled to rip like we both know an M8 should

Track~

 

[89sandman]

what rpms are you pulling at wide open throttle, should be around 7,600, if your lower minus weight, if your higher add weight. make sure you have the right helix for your altitude.

 

[trackvs2wheels]

Do you really only want to see 7600 rpm's out of these M8's? Just seems really, really odd since all our other sleds like to run at 8100... We are pretty new to Cat so any help is appreciated...

Does anyone know what the correct helix is to have in the sled??

 

[Mntryder]

I have a 07 M8 and like Sandman said it does pull the best around 7600 RPM's.
A straight 36 degree helix should come stock and work fine. Some are having good results with 42/36 progessive helix's

 

[opcruzer]

I rode the sled in question today and it just does not seem to be very snappy (I understand its an efi and that its different, we had an M6 for the wife and it ran great). I would almost think its got too much weight but we will have to watch the tach more. Like track said the 7600 seems low but if that what it needs, then we will make it work. I would imagine the gearing is still stock in this sled and just wanted to know if its working for everyone else???

 

[Lucias]

In my GF's M8 we are running the stock 36 helix, we only changed the primary to a Green/orange team spring and 77grm weights.. The highest elavation we ever get to is roughly 9k.. it engages kinda hard but it also pulls hard and constant..

 

[dirtoval#19]

Yes keep it at 76-7800 rpm; in my 07M8 i use a gold spring in the pri. with a 44-40 helix in sec. Didn't notce big differance between the straight 36 that came with the sled. I ride between 5-8k feet and use 77gram weights. Stock pipe with a PPP can.

 

[blackcloud2k]

I run my m8 at 7800. I thought most people wanted it around 7800? My sled at 7600 just seems a little weak but once I got it up around 7800-7850 it ran alot better. There is alot that goes into a helix decision like elevation, riding style, what you like to do aka trail, boondock, hill climb, ect...but yes as was said cant do much with out knowing what your rpms are.

 

[ItDoAble]

Tachs can be off, too. Some are seeing 200 or so RPM error in the stock gage .. so, 7800 could really be 7600. Long discussions back in 07/08 and the concensus seemed to be 7600-7800. In stock form, my 07 did best at 7800 but who knows how accurate the tach was. You might want to try the Cutler adjustable weights, so you can get it spot-on. Also, make sure your clutches are aligned and clean.

 

[richardsb014]

I put the SLP pipe kit on mine and went with their MTX weight set up. Ran nice and strong, but 200 RPM above the desired RPM. Added weight to get the RPM in the zone, and sled felt sluggish. Returned to the lighter weights, and power back on. Tach was off approx 200 RPM, and for a 2-stroke that can make a big difference.

68 grams should be the ticket with a stock M8 at 9000+ feet. Did you have the clutch alignment, parallelism and belt deflection checked? I would almost say the belt is a bit worn since you seem to be running the correct primary weights. Check the deflection.

 

[opcruzer]

My sidekick (trackvs2wheels) here seems to think that our M8 has 65 gram weights. It seemed to run good the other day. Will these efi sleds over rev if we are really that far off, because I think we are finally getting where we need to be for R's. How many of you guys have the 162" track and is that part of our problem here?

 

[GlennRMK]

68s seem light

I would go 70s and a stiffer primary spring

 

[MUZBOMB]

I would run 70grams and a orange/white primary spring. That is what i run when i am at 9000ft works awsome!!