M-7 wont hold rpms!!

[caterpillarman]

have an 06 m-7 and it has had problems pulling rpm since i bought it used. When the sled first takes off it will pull to just over 7700 but it only holds that rpm for maybe three seconds then drops to 7000-7200. When i bought the sled it was bone stock and it had the same symptoms stock as it does now with a d&d single pipe, boonie box, and can. I am not familiar with the secondary setup but the previous owner did install all the bd aluminum belt deflection adjuster and spring adjuster. Anybody have any suggestions?
Thanks in Advance.

ps running 68 grams in primary/ riding 7500 to about 10000ft

 

[Chris6060]

I'm pretty sure thats where its supposed to be at... Haven't ridden mine since last year, and for whatever reason don't remember what RPMs it was running at, but the M8 and M1000 sit usually between 7000-7500 RPM at full throttle.

 

[Rixster]

The M7 will spin faster then 7500. I am not sure how much more but I would guess around 8000-8200 with that pipe on it.

 

[mountainguy]

The M7 should be at 7850 stock

 

[tundramonkey]

Stock rpm should be around 7950, with the pipe maybe around 8100??? Have you checked the power valves? Could be causing your problem.

 

[lakeeffect101]

Clutching

To me it sounds like somthing is not right with your secondary. That is where I would start.

Good luck!

 

[Ski-Laxn]

I would suggest looking at your primary spring. Could be sacked out. The best setup for that sled is as follows
Primary yellow white, 68g weigts.
secondary orange with shift assist.
Or
secondary BMP torsional with there black
Primary 68g with slp black silver 120-300 will give you some more rpm on top

 

[m7]

Screw the plastic adjuster in till its about half an inch away from crover plate then try it.

 

[mmsports]

Clutching

I would do a once over on the whole sled.
Pull spring out of primary and inspect it then look at the weight and rollers make sure the rollers are smooth and that you do not have a weight of center hitting the side of clutch.
Check you secondary rollers make sure they are all in good condition

Pull you power valves make sure they are clean and check cable lengths

From their if it will not work it is tuning but I doubt it.

 

[akjimmyb]

My M7 did the same thing. Turned out to be something real simple. I had an Ultimax XS belt on it and out of the hole it would pull great, but then start losing RPMs the faster I went. A riding partner had a cat belt and I thru it in and problem gone. I needed less primary weight to run the XP belt. Just an idea to check your belt. Its simple. Mine only likes cat belts. If thats not it, I would check my weights. Did you say you checked to see if the power valves were opening?

 

[cjfarm11]

i would do what mmsports said to do. Check things over and make sure all your clutching and power valves are in check then expand from there

 

[caterpillarman]

thanks

first of all thanks to everyone i never expected this much feedback so quickly. Looks like I need to check the powervalves for sure as well as the clutching. i have inspected the primary and everything thing seems a ok as far as the parts arent completely worn out. I will check into the secondary as soon as i get back home this weekend. I have noticed when I ride for maybe 15 minutes that the secondary gets hot to the touch.

 

[FanMan]

Like akjimmy says, see what belt youre running. The xs belt will do EXACTLY what you mentioned. I started with 70 gram stock weights with the arctic cat belt, but with the xs belt, you need to run 63-65 grams. The xs belt really grips the sheaves, and with the right weights pulls great. Let us know what belt you find in there.

 

[caterpillarman]

belt

the belt is an arctic cat probably only has 25-30 miles on it. I replaced it when I first started having problems thinking it may be an easy fix

 

[907KB]

Stock RPM 7850. D&D Lite Pipe makes its power @ 8000-8100 RPM. First thing to get is a shift assist and Orange M8 Spring in the second. Drop the primary weight to 65's. That should get you in ball park. Check to see if your helix is stock, a straight 36 works best at elevation. Your R's will fall off like that if your helix is to steep.

 

[907RiDeR]

My m7 did pretty much the same thing, i was told it was the servo motor, got a 12 volt battery and hooked it up to the motor and sure enough it wouldnt spin. Bought a new servo for $350 and the problem was fixed, also if your PV's are gummed really bad the servo wont be able to open and close them, that could also cause it to cut out.

 

[minet]

907rider

did it go hgh rpm then drop? or just not get rpm ?

 

[keeton]

mine did the exact same thing when my primary $hit out on me. put a new primary and new yellow/white and runs great now.

 

[caterpillarman]

still struggling

well here is what i came up with this weekend. New rollers were installed in the secondary as well as a new spring. The spring was also replaced in the primary clutch. I removed the power valves and cleaned them as well. Sled still has mainly the same symptoms, i did notice that the headlights do not come on any more nor does the speedometer work, the tach does work however. wondering about the possibility of a failed voltage regulator or a bad servo for the powervalves. Any input guys?

 

[tatorsalad]

sounds like it could be a ground problem check the tail light wire and under the seat search m-7 tail light it has been on here a hundred times