I am currently riding an 04 Pro XR 800. I have done quite a lot of modifications to the sled, But I think I might need a little help as far as clutching and gearing go. I will give a list of modifications so you have an idea what I am working with. 2 SLP flow rites installed in the hood,SLP big air intake, SLP powerdome cylinder heads and twin pipes. I also installed a 136" by 1.5" track. In the primary clutch I have SLP blue yellow spring which has a rate of 140/310 and polaris 10-66 weights. In the secondary I have red/blk spring with 66/44.46 helix. The gearing is currently stock. The sled is only pulling about 7900 RPM, with the pipes SLP recommends 8200 RPM. Should I go with a different spring or lighter weights? I would also like more top end, the sled pulls hard off the line and through the midrange but peters out at about 85 to 90 mph. Maby if I get the proper rpm the sled will perform better. I am kind of new to this site so any input would be greatly appreciated.

Ive said it before and I will say it again. Why spend, in your case, THOUSANDS of dollars on mods that will show you little if any gains?????? How many times do you see a sled with pipes and motor work get spanked by an identical well setup stock sled.
Just my opinion....Sell the heads and pipes and replace with stock heads and pipes. Clutch it, jet it down and possibly gear it although with my setups I found the stock gearing worked best for me. I would be willing to bet you would see vast improvements in your performance all the way through and including top end.

After thought....SLP is wayyyyy off on their recomondations.

what's your jetting? Get the motor producing the horsepower first, then clutch and gear.

Your rpm actually are not off IMO. Any dyno tests I have seen for the SLP twins they run 79-8000, only higher on a long run. Put the 3 delrin washers in the secondary as mentioned here previously. One on each end of the spring, and one under the spring cup. You should be at about 470 main jets, not as rich as SLP says, needle #3, and only 91 octane fuel. If the det light comes on at full throttle, go up one main size until you can hold it WFO without it coming on. If it flashes for a second when you let off full, that is ok. As with any sled, do not run at 7/8 or 3/4 for extended periods. I assume you have the SLP heads as they say for low elevation? Do the above first before any clutching changes. Also, at the elevation you are around saskatoon, you should be running the orange/white ves springs with the new stainless valves, if you have not changed them already. Have you verified the clutch alignment, engine torque stop set tight, no gap, throttle cable adjustement for the slides to clear the bores completely? The 04 were also known to have the timing off from the factory, factory marks incorrect. I would have this checked and set 1-2 degrees above spec.

Right now I am running 490 main jets with holtzman attacc and the needle is in the #3 position. Plugs are always light tan and I am yet to see the DET light come on. The slp heads are low elevation 52cc. The exhaust valves gave out on me last season while the engine was still on warranty and I am sure they gave me titanium valves although I could be wrong. The exhaust valve springs are still stock. Can I get the orange/white springs from polaris or are they aftermarket? I have already set the carbs so they open full throttle and I have set the timing 2 degrees advanced. What are these Delrin washers and what do they do I have never heard of them until now.

The exhaust springs have to come from polaris. The delrin washers you can get from rec. supply. #930650. They keep the secondary spring from binding affecting shift out. I would try a 155/222 black/red spring as well, it will shift out easier on top end. Go down one more size on the mains. A single piped sled such as yours around stoon can run 440's no problem, you should not need to be 5 sizes larger with twin pipes, especially with the heads. I would say 2-4 sizes. Check if you have the titanium or stainless valves before they fail, as they will, it is just a matter of time.

I replaced the valves myself and when I picked them up from polaris I was told they were an updated valve so I hope they are stainless.

My son just picked up a 2004 pro x 800 with 700 miles on it, all stock. After the first weekend we weren't to impressed lacked performance and hard on fuel, we installed 430 mains , needle stock positoin#3, 66 gram weights, 24/40 gears , new primary spring red i think,runs strong good on fuel 12 mpg hard riding. he topped it out at 103mph on the speedometer. Top speed not important to us, mostly
concerned with corner to corner speed this setup seems pretty good. The rest is stock,he is looking only to upgrade to new stainless steel valves. good luck with your set up!

Stainless of course a magnet will stick, stock it will not. Check on the blade area of the valve, not the center.

thanks for the input. i will try your reccomendations and test them out this weekend. Thanks again!

a magnet will stick to the stainless valves? must be a weird grade of stainless