01 800 rmk gut the air box.....yes or no?

[rmkboy]

I have a 2001 800 rmk. I recently put in a single slp pipe and can, changed the primary weights and spring to the specs on slp, changed the secondary spring and put in a slp mountain helix and new buttons. On the flat she is a rocket, but climbig not so good. I am trying to watch my rpm's when climbing but get bounced around to much to get a acurate reading. It seems like I climbed better stock. Should I gut my airbox for better flow and how do I jet? Currently 410 and 390 for jetting, I am between 3000 and 6000 feet.

 

[theultrarider]

Definetly gut the box, but that won't fix your issues. I didn't run a slp pipe on my 01 in hindsight, so I can't give you any jetting reccomdations. I was going to say that I was running 410/390's at sealevel but that was with a stock pipe. How did your plugs look after a long pull? Btw, removing the shelf has a minimal effect on jetting.

 

[rmkboy]

the plugs looked good not to lean or rich. I just moved the secondary spring to the next notch #2 SLP calls for #1 I am going to try it on Sunday. What about lowering my primary weights? Should I jet one richer if I remove the foam and shelf from the air box?

 

[theultrarider]

I just looked at the slp instructions and it sounds like you have set yours up "by the book". In my experience, slp's jetting charts are VERY conservative. I would think that you may want to drop 2-3 sizes from where you are AND remove the shelf. I have slp twins on three sleds currently, and have had slp singles on several also. All have ended up jetted much leaner than slp's charts. Just becareful and keep an eye on your plug colors. Hopefully someone at your elevation will jump in here riding the same setup and help you out more.

 

[dexter]

Remove shelf & put a slp big air kit on, it's a must with the pipe. should have 10-62's or 10-64s. your jets should be fine just check plugs and maybe not pin it too much at 3000'.

 

[rmkboy]

I run 10-64's......so when I gut the air box I don't need to jet riher? I just want to climb

 

[dexter]

when I gutted the box and put the big air kit on I had to richen it up. It makes quite a difference with all the extra air. but as always piston wash tells the storey on jetting

 

[rmkboy]

Do you remember if you went up one or two jet sizes?

 

[dexter]

can't rember for sure how many sizes 1 would probaly do it. I do remember that i ran 460's at sealevel and 420's at 4500ft though. but a ran psi twin pipes back then. I would check piston wash to tell for sure. If you haven't checked wash before you should have 2 clean areas above the ring gaps (on top of piston) about half the size of your small fingernail. rest of piston should appear black. you should be able to see this through the spark plug holes with a light. checking piston wash is the only way to properly jet without o2 sensor or egt's. Also check clutchs with a felt pin to see if they are fully shifting out.

 

[rmkboy]

Well alrighty then.....thanks for all the help and I will report back after Sundays ride.

 

[rmkboy]

Well everything went well......a little less power than I was expecting but she ran good with the gutted air box and setting the driven spring one noth tighter. Thanks again for all the help.