Not hitting the Rs, 16 assault

[j9845]

Seem to start loosing Rs at the end of last year. I ride in togwotee and out here at the moment. I can only get 7900 or so in deep snow. Last year right after break-in I could hit 8200-8250. Not sure what's going on. I just put on a new gates carbon belt and didn't seem to make a difference. Belt deflection is good.
Set-up - 10-60 weights, slip blue & pink spring, evolution can, everything else stock. 600 miles on the sled
I run on non-ethnol setting, usually throw a gallon of 110 into a full tank.
Any help would be appreciate. Thanks guys!

 

[Indy_500]

Check your powervalves, at 850 miles mine were solid carbon

 

[G-Force]

When it was hitting target rpm last year, was that with stock can? Maybe put the stocker back on and try again?

 

[j9845]

I wouldn't think they would've carbon up yet but will check them. What were you seeing for Rs during that time.

I did have the can on last year but I did think about swapping it out.

The spring I put in was in my pro that had some miles on it so I'm going to try a new slp spring and NGK iridium plugs

 

[goforbroke]

check primary clutch weights and rollers. I normally get more than 1000 miles, but could have a bad spot?

 

[Betterview]

Iridium plugs are not the best choice for a 2 stroke. They are a long life plug designed for 4 stroke engines. BR9EYA is a better and safer plug.

 

[j9845]

I am goin to throw a new primary sping in, new plugs and throw the other belt back on.
I'll check rollers and weights when when I'm in there. Thanks guys

 

[j9845]

Thought I had it. The cap on the spark plug was stuck on the boot. And couldn't get out. Got a new cap and put plugs in. New primary spring.
I double checked my weights and they are 62s grinded down to 61.5. Owners manual calls for 62s for 8-10k.

I can hit 8150 on the trail. Off trail I have only seen 8000 a couple times

Not sure what else to try...

 

[Indy_500]

Not sure what else to try...

Personally I don't know anyone with a 1000 mile axys that still pulls 8300 consistently sooo....

 

[j9845]

I'm only at 620 at the moment. Figure it should still pull 8100-8200

 

[akpowderhound]

Low elevation with 500 miles.
My sled pulls 8450 consistently with 68g belly busters and a 56-42 .36 helix.

 

[j9845]

Can only get to 8050 sometimes, got the exhaust valves relearned and TPS checked. Haven't reflased the ECM yet. Any other ideas?

 

[yamikilr]

Check compression ?.

 

[j9845]

Check compression ?.

More than likely go to the dealer to when I get back so they can check it

 

[adamg]

Please keep us informed of what you find out.

Can us home amateur mechanics clean the powervalves on this motor? Or does the sled need some kind of computer powervalve calibration after taking them apart?

 

[Sage Crusher]

No Pretty easy- but the steering is a SOB to get out of the way with the one piece design.
900 miles and mine were full of gunk running the polaris gold-
The new design has springs but pretty straight forward when you pull it apart- Just do one at a time, even though they are housed together- you can still clean one from the other.

JUST DON'T MESS WITH THE CABLE SETTINGS !!!!!

 

[Overthehood]

My sled has 1100 miles and I'm having similar issues. Holds up to 8350 below 7000 ft. Elevation. When I'm over 8500 it drops to around 8000 rpm. Running mtx 62s with 2g rivet in the first hole. Have SLP stage 2.

My power valves started sticking at about 600 miles. In that case it waffled from 7000 rpm to 7700 or so, really sick and erratic. Had valves cleaned and recalibrated and it came back to normal.

I feel like the motor is just weaker now. I could hold 8350 up to the 500 to 600 mile mark at high elevations but it slowly got weaker and weaker with elevation. It's down about 4g from where it was. Anything you find out would be appreciated. Our dealer here is a joke. Tps, reflash? Eric, Mountainhorse, anyone??

 

[adamg]

My sled has 1100 miles and I'm having similar issues. Holds up to 8350 below 7000 ft. Elevation. When I'm over 8500 it drops to around 8000 rpm. Running mtx 62s with 2g rivet in the first hole. Have SLP stage 2.

My power valves started sticking at about 600 miles. In that case it waffled from 7000 rpm to 7700 or so, really sick and erratic. Had valves cleaned and recalibrated and it came back to normal.

I feel like the motor is just weaker now. I could hold 8350 up to the 500 to 600 mile mark at high elevations but it slowly got weaker and weaker with elevation. It's down about 4g from where it was. Anything you find out would be appreciated. Our dealer here is a joke. Tps, reflash? Eric, Mountainhorse, anyone??

How about a top end?

 

[Overthehood]

Top end is what I'm worried about. Compression is 105/110.....should it be that weak at 1000 miles???