09 850 xp no power???????????????????????????????

[cornicejumper]

So a little history... Took this into my dealer about 6 months ago for lacking power, it would only pull about 6400 rpms. They did some clutch work and told me it had sucked some dirt and needed a valve job, at this time no blue smoke they changed the oil and said to go ahead and use it because it still runs fine and your not gonna hurt anything else. Then about 200 miles later it started smoking horribly and before i got back home it spun a rod bearing.

So now i have pulled the motor and completly rebuilt it.. New pistons new rods all new bearings new crank, had the cylinders and head checked and adjusted the valves. Put it all back together and it runs great starts right up idles normal, no smoke but it still wont pull rpms, almost sounds a little doggy like the ignition timing is off but i have been told this is not adjustable? I found a spec for it in the service manual at 6 degrees btdc but nothing else on how or if its adjustable or setable by any means.


Im at a loss as to why it wont go past 62 or 6300 unless the dealer screwed up my clutches wich he is sure they are fine. Any and all ideas and input would be greatly appreciated as i have just spent about 1500 dollars on this thing and really cant afford to randomly throw parts at it.

 

[zeebs]

So a little history... Took this into my dealer about 6 months ago for lacking power, it would only pull about 6400 rpms. They did some clutch work and told me it had sucked some dirt and needed a valve job, at this time no blue smoke they changed the oil and said to go ahead and use it because it still runs fine and your not gonna hurt anything else. Then about 200 miles later it started smoking horribly and before i got back home it spun a rod bearing.

So now i have pulled the motor and completly rebuilt it.. New pistons new rods all new bearings new crank, had the cylinders and head checked and adjusted the valves. Put it all back together and it runs great starts right up idles normal, no smoke but it still wont pull rpms, almost sounds a little doggy like the ignition timing is off but i have been told this is not adjustable? I found a spec for it in the service manual at 6 degrees btdc but nothing else on how or if its adjustable or setable by any means.


Im at a loss as to why it wont go past 62 or 6300 unless the dealer screwed up my clutches wich he is sure they are fine. Any and all ideas and input would be greatly appreciated as i have just spent about 1500 dollars on this thing and really cant afford to randomly throw parts at it.

how many RPMs you looking for?

 

[sledheadrevxp]

I would pull your clutches apart yourself so u know for sure. Have you done any aftermarket clutching or is it stock?

 

[zeebs]

I would pull your clutches apart yourself so u know for sure. Have you done any aftermarket clutching or is it stock?

I dont know for sure but 62 to 6300 I would think is fairly close to the top of the RPM range anyways. But I have a question, why do you guys think its in the clutch? It seems to me if your actually missing RPMs the its in the engine since your not measuring the revolutions of the clutch and your not going by ground speed. Just like when you go from high range to low range, your machine doesnt pick up another 3000 max RPMs, it should pull the same RPM's max weather in high, low, or neutral but your speed is whats changing. I dont know for sure though Im just thinking out loud. What do you say?

Are tires stock or something heavy?

 

[cornicejumper]

The 850 builds its power at 7200 rpms the soft rev limiter kicks in at 7500 and the hard limiters is somewhere around 8000. The tires are 26x11x14 maxxis bighorns all the way around, problem was there with the stock tires also. In the mean time i have pulled the clutches and taken them apart, everything seemed to be in order. Did a little testing with clutch cover off so i could see how they are moving.

Took the belt off and it will hit the rev limiter right away. with the belt on going down the road in low range it will shift all the way out with a little hesitation at about 6200 then after a few seconds it will take off. In high range it goes to somewhere between 62 and 64 and its only shifting about 3/4 of the way i held it wide open for about 1/2 mile and it never would climb past that point... Not much of a clutching guy so im still not sure what to do??

 

[cornicejumper]

so after a little testing found the fuel pressure to be about 28 psi and the book spec is 43+-3 so its quite a ways out of spec. Hopefully this is the problem.. We took it all apart and found a matching pump at the auto parts store, problem is the spec on the pump is 80psi, im hoping that since there is a pressure regulator is the system that this pump will work.

pump number i found is an e8335 airtex

 

[cornicejumper]

Holy sh>t man new fuel pump and this thing is awesome. Cant even remember it running so good, ever!!!!

 

[zeebs]

Didnt figure it was in the clutches. Glad to hear you got it fixed though. Although I would worry a little about that high of pressure fuel pump. Seems a little excessive.

 

[cornicejumper]

I was very hesitant to put that pump in but there is a pressure regulator inline that dumps the excess back in the tank. Im only getting 45 psi at the fuel rail which is right in spec with what the book says 43 + or -3 so hopefully all is good!!

 

[zeebs]

hopefully it all remains good. Glad to hear you can now enjoy the quality ride of a Polaris!