M8 Not reaching full RPM's and It's not the clutching!

[WyoBoy1000]

Every sled I have owned needed the secondary rebuilt practically from new, I would bet if you disassemble the secondary when you pull the back sheave off it comes up to that last little bit then gets real tight that last 1/2", For $80 BDX will rebuild it, machine the shaft so its true and put in a pushing that sucks up the tolerance. Makes a huge difference.

But try a new belt.

Maybe your tach is just off a few hundro

 

[Thunder101]

Im having a hard time with you saying it would not rev past 8050 w no belt on the trailer. NO WAY. I would need to see it myself even if you were my best bud I would still have to see it. Sorry. Follow others recomendations and get at the secondary. Good luck, chasing things can make you go mad. so have beer on hand.

 

[Blk88GT]

What do you have for an air intake? How do the plugs look if you hold it WOT down a trail or up a hill?

 

[WyoBoy1000]

Im having a hard time with you saying it would not rev past 8050 w no belt on the trailer. NO WAY. I would need to see it myself even if you were my best bud I would still have to see it. Sorry. Follow others recomendations and get at the secondary. Good luck, chasing things can make you go mad. so have beer on hand.

I didn't read that part,

check the plug wires and caps screwed on, power valves, cables and servo

unplug brake wiring at brake rotor. In fact I would unplug as many wires as possible (hood, handle bars etc...) check baro tube just because. unplug and dry out all connections

Did you hook up any accessories to the wrong wire.

 

[summ8rmk]

Here is a stupid question. R u sure its running on 2 cyl. If not the primary that is the only other thing I. Could see preventing max rpm without a belt .

 

[offroadmatt]

Every sled I have owned needed the secondary rebuilt practically from new, I would bet if you disassemble the secondary when you pull the back sheave off it comes up to that last little bit then gets real tight that last 1/2", For $80 BDX will rebuild it, machine the shaft so its true and put in a pushing that sucks up the tolerance. Makes a huge difference.

But try a new belt.

Maybe your tach is just off a few hundro

Will look into this maybe even buy a new one. Don't think its the problem but the only way I'm going to prove it is to try a new one. I'm going to try a new belt for sure on the next ride just to see. Even though this belt only has 6 rides on it.

What do you have for an air intake? How do the plugs look if you hold it WOT down a trail or up a hill?

SLP Intake. Plugs look great. Adjusted the Fuel to make them this way. EGT and AFR are spot on.

I didn't read that part,

check the plug wires and caps screwed on, power valves, cables and servo

unplug brake wiring at brake rotor. In fact I would unplug as many wires as possible (hood, handle bars etc...) check baro tube just because. unplug and dry out all connections

Did you hook up any accessories to the wrong wire.

I changed the plus & caps to the SLP MSD one's and haven't had any issues with them like I did with the stock ones always coming off. I checked the Powervalves for sticking and the cable pull feels great springs right back. I also checked the adjustment. Even took it a step farther and marked the servo pulley and reved it to make sure they were opening all the way.
Don't think I have any electrical issues like a bad wire because everything seems to be working fine. Before I even rode the sled I put Di-Electric grease on all the connectors.
I've checked the Baro Tube a thousand times and tried several different routing options. I think if this was a problem I would see it in my AFR.

Here is a stupid question. R u sure its running on 2 cyl. If not the primary that is the only other thing I. Could see preventing max rpm without a belt .

I'm positive EGT's prove it and the fact that it wouldn't run at all with only one cylinder. The thing runs great at all RPM's its just missing the top couple hundred that would really make it sing.

 

[WyoBoy1000]

How are the exhaust donuts, any cracks, maybe can is falling apart.

 

[Blk88GT]

Out of curiosity, what are WOT EGTs and AFR on the trailer without the belt on? LOL

 

[summ8rmk]

Is there any chance you could swap complete primarys with a buddy? U said it runs great at all rpms, but short a couple hundred that would make it sing. If it were anything other than clutching I would think it would falter at different rpms. Sorry I'm so stuburn. U also said u tried mtx weights don't u have to shim the spider for those? Did u take the shim back out after removing them?

 

[Tonysnoo]

You might want to check the crank runout, especially on the mag end.

Maybe its as simple as a loose fly wheel......timing key backwards????
I

 

[tchriste]

Have you tested the TPS for correct voltage etc? And what are your EGT/AFR at WOT? I ask this as if the TPS is off then you might not be getting the fuel to pull past the stated RPM. It would seem with everything else removed (secondary, drive etc) your choices are limited as to the cause of your issue. It would seem you have been very diligent on your trouble shooting.

 

[VRod]

Borrow a buddies secondary and test it. Have seen this multiple times. Secondary is warn and slightly out of spec. I also went thru the whole sled the first time and couldn't believe it was the secondary.

 

[RCR3]

BDX No longer rebuilds secondary clutches its posted on their web site! Also try taking out one or both of the black plastic rings in the secondary I took mine out and gained close to 400RPM @ 9000FT. elevation! I did this at around 1000miles because I couldn't get more than 6800-6900 RPM at any elevation whether it was 5000ft. or 10000ft. after I could hold 7300-7500 on an M1000 at what ever altitude!

 

[WyoBoy1000]

BDX No longer rebuilds secondary clutches its posted on their web site! Also try taking out one or both of the black plastic rings in the secondary I took mine out and gained close to 400RPM @ 9000FT. elevation! I did this at around 1000miles because I couldn't get more than 6800-6900 RPM at any elevation whether it was 5000ft. or 10000ft. after I could hold 7300-7500 on an M1000 at what ever altitude!

That sucks

 

[AdrenalineAddict]

You mentioned low gearing, if you went ridiculously low such as 2.4:1 or 2.5:1 you may have a very difficult time running 8,200 unless you run a very shallow helix and weights that are 4 to 6 grams lighter than the norm. This is just a thought, I've rode with alot of guys who can't get r's with stock components after gearing down to far.

 

[large52]

Might just be your tach. My digital tach always shows lower than my analog one for some reason. 09' standard has both.

 

[skidooboy]

BDX No longer rebuilds secondary clutches its posted on their web site!

where is it posted there? i was looking but, couldnt see this.

also, are there any others rebuilding/trueing these secondaries? i thought one time someone said speedwerx was machining the shafts and splines for better alignment. not sure if they can do the whole shabang or not. ski

 

[markoo]

Have you checked your compression?

 

[large52]

Racinstation rebuilds primaries and secondaries.

 

[killerrf]

you can make one of these up and test throttle position sensor output at different positions.