2011 m8 top speed seems a little low

[wooleybulley]

I recently picked up a 2011 m8 with 1099 miles and the thing runs great aside from the fact the top speed seems a little low.
It is a 162 with a brand new 2.6 power claw track and has the polaris clutch conversion done to the primary. The guy i bought it off says the helix has been changed in the secondary.
Right now maxed out on the trail i get about 65 to 68 mph on the trail at about 8500 rpm
It is very responsive untill above 2/3 throttle then i dont seem to gain anything out of it.
i figure i should be getting about 85 mph out of it at least
any ideas?

 

[Summiteer]

I recently picked up a 2011 m8 with 1099 miles and the thing runs great aside from the fact the top speed seems a little low.
It is a 162 with a brand new 2.6 power claw track and has the polaris clutch conversion done to the primary. The guy i bought it off says the helix has been changed in the secondary.
Right now maxed out on the trail i get about 65 to 68 mph on the trail at about 8500 rpm
It is very responsive untill above 2/3 throttle then i dont seem to gain anything out of it.
i figure i should be getting about 85 mph out of it at least
any ideas?

I doubt you would see 85 with a 162 and mountain gearing. These things aren't designed for top end. Want speed, buy a short track. A buddies '14 MXZX shows top speed of 189 kmh on the speedo memory. Apparently the wind tries to remove your helmet at that speed.

 

[wooleybulley]

not looking to go race on the river or anything but some track speed will help with the climbing

 

[tater]

8500 rpm seems high...

 

[wooleybulley]

i should also mention the clutch seems to engage at a rather low rpm 2500ish if i remember right, i just assumed this was due to the polaris primary being 3 lbs lighter than the stock cat primary clutch

 

[Thunder101]

I have a P85 and (44/40 helix)on a M8 2011 153 and it does 85 on the speedo, dont do it alot. I also have a 09 M8 modded than has theP85 and stock 36* helix and it gets to 80 quite a bit. Now we are taking about at home on the flats 1720 ft.
Your over reving at 8500 !! you need to see 8-8150
FYI the 2011 is stock and I run 71gr poo weights(72gr with the back side of the tip ground) 70 would probably work with you having a 162.

 

[moyiesledhead]

8500 rpm seems high...

Yup. You're clutched about 500 rpm too high.

 

[Modman]

draw a line with a felt up the inside of the clutch sheaves. Wherever it wears off too is how high the primary is shifting out and how far down the secondary is shifting out. Several things can be happening - primary isn't fully shifting out, secondary is not fully opening (this might be the issue - seen this lots when people think its a primary issue - especially that the helix has been swapped), motor won't pull the weight all the way out, etc. Check finish rate on the primary spring, you might need less spring or more weight to get the RPM down. I would go back to the stock helix too and see what happens, it might be too shallow and its not letting the belt drop all the way down or it might have too loose of a spring and its not gripping the belt, meaning your slipping and losing speed.

 

[wooleybulley]

Thanks for the help I'll check it out

 

[plio7]

My 07 m8 153" never broke 135kms.... My 2012 162" I have never broken 120..... Top speed means nothing to me I would rather have the lower top speed and the torque to keep it spinning in the deep snow. If it's running good who cares about top speed.


With that said I don't lack any torque on the top end either

 

[marcel.]

8500 rpm seems high...

agreed

 

[Iamcatman]

My 2009 M8 I have had to 93 mph on the speedo. I have all stock weights, clutching, and 153 track. This was wide open on a lake. pulling high rpm's at 8250-8300. (stock mountain weights at low altitude) also, engagement is at about 4000-4500 rpm. If i was you, I would change that poo poo clutch out for the stock one, and mess with the weights then. 9500 km on this sled, and havent had any problems with stock clutching.