PD10913

Member
Apr 1, 2007
16
0
I need a bit of general advice about my 98' XR600 and some work I am planning to undertake. I've always been a bit of a horsepower monger and I'm currently looking into ways of giving my 98' XR600 a bit more poke. I realise there are many other breeds out there that will chew up the XR600 but overall I love the bike, it's reliable, pretty much bullet proof and great fun to ride.

Firstly I'm in the process of deciding on a new pipe to replace the stocky which will be more than likely an FMF Powercore 4 or Supertrapp IDS2 as I'm told either of these will give the most power improvement.

Secondly I am looking at a big bore kit taking the 600 to 630 or 654cc, Is this a good or bad idea, bearing in mind I am not a mechanic, nor am I a bike engine guru but I am quite capable of working on the engine as I have pulled apart and rebuilt several in the past, I just don't really understand the implications of carrying out this sort of mod on the bike and what else might be involved.

Any advice would be appreciated and I suppose at the end of the day, I just want to have a bit more of a hobby in working on the bike and possibly then owning an XR600 that is a little bit different.
 

Jan 3, 2007
1,860
0
The XR600 can also be bored out to a 720 if you felt you needed that much power. On the other hand you will see lots of power gains from taking off the air box lid and rejetting the bike properly. The exhaust will also let the bike breath beter. On the other hand if you buy a very un-restrictive exhaust you will loose backpressure and loose power, but the exhausts you listed would be fine. You might also want to look into getting a new Cam that has a different spec that will shift your power to a more upright and reving kind. Good luck.
 

PD10913

Member
Apr 1, 2007
16
0
That's great, 720! now that would be good fun. I will initially fit the pipe then see where to go from there and I will definitely consider your options as well before I undertake any major engine mods.

Thanks very much for your input.
 

pryor

Member
Oct 21, 2006
171
0
MY brother had a XR600 not sure of the year, he used a supertrapp pipe, big bore kit I think 650?,hotter cam, cleaned up the ports and had an aftermarket air cleaner. I only rode it once and dont have a lot of experience with big four strokes but it seemed real fast to me.
 

xrmax

Member
Jul 26, 2007
5
0
jeez, 720, that's huuuge

all i've done to mine is staintune header and silencer, airbox mod, fiddle with the jets and that's pretty much it. now i find it hard to keep the front wheel on the ground haaha
 

helio lucas

~SPONSOR~
Jun 20, 2007
1,020
0
the problem is if you bored too much the cylinder without any more mods is very likely to kill the top end of your bike, but i can assure you the engine in lower revs will be really fun...

when you bore a cylinder you are increasing the displacement. ok, but also raise the compression ratio and limiting the breath of the engine...

i agree with "2 strokes for life" about the air box and exhaust system... itá a good way to start with...

a simple holes in the air box and jetting will lift power but the bike will make more noise from the intake system...
 

cujet

Member
Aug 13, 2000
826
5
XR600 mods

Years ago, I did the mods you talk about to my XR600. Bit by bit. After all that, I found that the best bet was to do it all at once. I like the big bore kits, but a significant change is necessary to get a seat of the pants improvement. Don't expect 30cc to give tons of arm ripping power. 30cc is only 5%.

My suggestion is to add a good sized big bore kit, better cam, better pipe (don't forget the other mods necessary, such as airbox) and then jet it. This way, you only tune it once. The final result is a big jump from what you currently have.

Chris
 

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