Rx1 Seems to Have High Rpm's

[Yammi_Rx1]

hi, new to this site, i had asked a question about carbs an had it answered successfully so i thought i would put this in a more popular column.
I have recent got this Rx1 Mountain from the states and everything appears to be stock on it, no mods, 135 mains,17.5 pilots O.S.O primary with a White secondary( not sure on weights/rivets).
im between 550-700 elevation(1900-2100 feet).
This Rx1 seems to be reving a little high and by that i mean, if im in some powder and i give it a good chunk of throttle in 2 seconds itl quickly climb to 8000-9.800rpm even low 10s then taper off ,i dont know what its suposed to be at for a mtn machine, or if im movin along on trail or some powder for a stretch and i give about 3/4 throttle ill easily see over 10 and itl go in the 11000's if i let it rev that high but never do, on flat trail after u let it plain out it always stays it the 10,000 rpms and thats goin 90-110 KM not miles, which i feel again the rpms seem high. what can i do or is there anything i can do to address this without changing gearing ? would putting in different weights/rivets and spring calm this down a bit? if so,what type of weights/rivets/spring should i be lookin for? i think clutching is my major thing i dont know much at all about so any advice would be worth the weight of gold to me. thankyou

 

[Yammi_Rx1]

i have come across some information via mail,i also found that this may calm it down some, let me know what you guys think, it will spend most to all of its time flatlanding.
Primary spring Y-S-Y , weights 8FA-17605-10-00 with both rivets installed,Rivets are 17.2 steel (4.5 grams) inner and 17.2 steel (4.5 grams) outer

 

[grader]

being a mountain machine the clutching was set for high altitude and thus less power output. at low altitude and on trails you are under geared and over powered. your rpm is ok except for it getting up to 11000. this is too high and should not go above 10700-10800 max. you can add heavier rivets to the stock weights to bring down the rpm, 1 or 2 grams to the tip. unless you are going to take it to the mountains to ride or ride in deep snow, i would gear it up, as maxing out at 110 km is too low for trail/lake running.

 

[tedgoesfast]

mine pulls much better and is alot quicker when it starts out at 10300 and pulls to 10500 at 100 mph.Ive learned they do not like to be lugged like a two stroke.the quicker i can get it to 10300 the better drastic differance when tach get there fast like 10 lengths

 

[MtN_Rx1er]

these parts you listed=(Primary spring Y-S-Y , weights 8FA-17605-10-00 with both rivets installed,Rivets are 17.2 steel (4.5 grams) inner and 17.2 steel (4.5 grams) outer)

Are the same exact ones i am going to try in my 04rx1 mountain as i can easily see 11000 rpm + out of the hole and in the top end so i came across those parts from Sled Dogs Air Box Mod thread, i just picked up my weights today with both holes 4.5 g each(72.83 per weight) along with the y-s-y spring, im going to try the weights with both springs, ill probably end up with the y-s-y, really hoping these weights solve the higher reving and i guess just chose wich spring feels comfortable, was curious about the y-s-y not giving me good hole shot but i trust sled dogs input as he did his clutching this way and has nothing but postiveness about the mod, so i cant wait to try it out tomorow!
good luck!

 

[Sled Dog]

i have come across some information via mail,i also found that this may calm it down some, let me know what you guys think, it will spend most to all of its time flatlanding.
Primary spring Y-S-Y , weights 8FA-17605-10-00 with both rivets installed,Rivets are 17.2 steel (4.5 grams) inner and 17.2 steel (4.5 grams) outer

This will bring your rpm down to where it should be, your motor has its highest HP at 10250 rpm and I would gear up a bit for flat landing. My sled is a 04 rx1m and it is geared 24 top 40 bottom with the 70 link stock chain with the exact clutching your putting in but my air box is modified.