Old news I know but what is the quickest way to get some extra ponies out of my 2000 xr 600r?
Take the seat off, remove the snorkle there going into the airbox.
For tight trails, run a 13 tooth front sprocket.
Take the header off and grind off the welding slag left on the side flange.
From there, things are going to get more expensive.
If you keep the stock carb, rejet immediately! 68 pilot and 155 main works well for most.
If you can stand the louder exhaust, aftermarket! You can get like the Thumper quiet baffles also. many places sell those. You may need to step the main up to about a 158-162 after that.
You can add like a Uni or K&N filter with a less restrictive backfire screen in the intake. You may get a bit more hesitation.
The best bang for the buck though is something like the WB 1652 cam. If you want power, go with a cam. I have one on the stock bore and it is super nice!
After that, you may have problems with the carb. i went with an edelbrock and pretty much solved all my problems.
That is about it. After that, big bore kits and turbos. That is about it, you have maxed out the beast. What is scarry is that after a cam, intake , exhaust and carb, you are putting out about as much as a stock CRF450. Makes you reconsider things!
In addition to matt's mods you can do some porting/polishing on the intake and exhaust ports, thumper racing 660 big bore kit, I am using the HRC cam and 72pilot/172 main. All mods listed below. After all these the bike felt 100lbs lighter!! not actually, it just runs like a bat out of hell!!
What they siad is good, but you siad the quickest way, remove the snorkle and go with a pipe and filter, I'm running a 70pj and 170 main, 14/48 for gears, and it will wheelie all day in 4th.
What temp & humidity. Those jet #s sound rich.I thought main was stock 155 or 152 then uncorked is 158?
For some reason, my xr600 likes the 70PJ, I was running a 68PJ, but it would only wheelie 1st&3rd, never in 4th, so I put a 70PJ just to try it, and it's wheelies in 4th all the time. As for the main jet being a 170, i was running a 165, it would miss with a 168, but I went to Glamis and it was lean, if you pulled the front end up it would go back down, so I put the 170 in it, and then when you pulled the front end up, the more gas you gave it the higher and longer the front wheel stayed up, while with the 165 it would drop down the more gas you gave it, lean.
The air box is open at the top, with a UNI, and the side plate has 5 3/8 holes it, so it get allot of air, and with these jets there no carb noise like you would get in a lean bike.
[ March 25, 2002: Message edited by: Turner ]
I have a newer, very similiar post.
Does the mods here also pertain to an earlier XR600R, 1994 to be exact? Also; a riding buddy has a 1993 XR600R, is it the same for him?
Here are some specific questions;
1). What is the maximum compression ratio I can have and still use 91 octane gas? and is it a function of which cam I use?
2). Does the extra compression, and/or cam, make kick starting even harder?
3). Should a new carb be part of the picture, or is the stock unit sufficient?
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