XR600R 1996 Mods

Just brought my bike into the shop blew the oil rings.

Im get a big bore kits for it. a 4mm bore over and 101mm boresize which will bring the 600cc to 640cc, i will also be adding a stage 1 hotcam. Is there anything esle that i will need to upgrade or tweek like the carbo or anything like that???

i also have a FMF powerbomb header on it with a supertrapp pipe!

If anyone esle knows of anything i should look out for or anytihng else i should upgrade to i would appreciate it!!!


You better make sure your chain and sprockets are in good shape. Keep the drive components clean and lubed, the new power will eat though that stuff fast.

If it were mine, I'd change the fork oil too - an easy job.

Got Pro Tapers?

Do you have any pictures at all?

I just changed my rear sprocket a couple of months ago, I know i will be needing a new chain.

I put a picture of the bike on the Garage Part of this site.

Thank you for the tips on the bike!

Definitely examine the jetting after making any power modifications.

I have a 96 that I am doing a engine build to as well. Going with 98mm bore 610cc kibblewhite valves and springs, hot cams stage 1, xrs only piston kit, new timming chain and guides, probably a twin air filter

i have a plated '99 XRR... so here's the list done to mine:

one used xl barrel - so you don't have to sleeve

one new JE piston to get mine out to 654 - stock stroke

Kibblewhite intake and exhaust valves - stock dia.

Kibblewhite valve spring and retainer kit

four new Honda guides

new HotCams stage 1 cam

new Wiseco cam chain

two new cam brgs

hi-flo stainless exh header - primary pipe welds smoothed and ports matched

FMF muffler

XR's Only 41 mikuni - bored out TM38

airbox modd'ed - aftermarket foam filter - carb vents end in airbox

head: exh ports smoothed - minimal material removal except in valve pockets

int ports opened up, reshaped, pockets reworked, guides bulletnosed, port divider reworked heavily

combustion chamber>valve seat transitions all blended, spark plug hole blended, a large overbore creates a squish ring so dome>ring transition sharp edge lightly chamfered so as to remove minimal material and keep compression ratio high.

intake manifold matched to head

rockers lightened/smoothed/polished - decompression rocker has all unness material cut away and then polished

aftermarket IGN box

AMR coil

oil cooler - rt side cover modified to run "pressure" oil thru the cooler - not scavenge oil

oil line to head rebuilt w/ 1/4" tubing but using the stock bolts at either end as they are sized specifically for where they are installed.

according to my trail tech trip computer, redline is just over 9 grand. motor runs well down low, then just goes and goes.

things i would change/do differently:

XR's Only 41mm mikuni - carb is not offset bored. motor runs good but i am still working to get a consistent hot start on two kicks. kit comes with a motion pro throttle but the sleeve is for a 38mm carb. motion pro sells a sleeve (which i finally purchased) to match the 41mm mikuni. one should not have had to buy the correct sleeve to get proper throttle action. SO i would buy a TM38 and send it out for offset boring or bend over and buy an FCR (altho i have never run one...)

HotCam - well, i consider the stock cam/plated lifters the number one flaw with this engine so why repeat the error?? get a hardened cam and matching rockers from webcam, megacycle or XR's only. solve the problem once and for all. i have no complaints w/ the HC grind, but seeing what the mild HC cam did, i am _really_ eager to try a hotter grind

i should have split the cases and installed an upgrade rod/brg kit. at the same time i would find a way to install a jet to spray the piston underside and consequently add additional lube to the small end of the rod (honda flaw #2 imho)

do the big fin mod to the head and make sure to find a way to direct more air to the head as well. one or both as wallet and fab skills permit.

helicoil all threaded holes in head and barrel now - you will prob do at least two or three during the time you own the bike. A helicoil is so much stronger than the aluminum and allows consistent torquing of bolts also...

on you bike rj, very carefully inspect the rockers before putting them on the new cam. check your cam chain for strech - highly recommended to just replace it w/ new! clean and inspect the hard line carrying oil to the top end and make sure it has no obstructions.

just my two cents...

Hey I have pretty much the same bike as the poster of this thread. I have a 1996 xr600r bored out to 654cc and hotcams stage 1, supertrapp slip on. I am having some trouble with the bike idling. It doesn't want to stay on unless I turn up the idle very high. Also takes a while to start(like 20+ kicks when cold). What should i do?

"Also takes a while to start(like 20+ kicks when cold). What should i do?"

Mine does this when its REALLY cold. Try this...

Leave gas off, pull decompression lever if equipped, get situated right and give it 10 to 15 kicks as fast as you can.(this is fairly easy and effortless, as long as you don't hit a compression stroke). Then without too much delay, turn gas on, get engine on the top dead center, compression stroke. (and I know this normally is a HUGE no,no but its what I've found to work well with mine), give the throttle one full twist then don't touch it ever again untill its running well and giver hell with every bit of weight and quickness you can pile onto that kickstart lever.

The only thing I can figure is that the 10 to 15 fast kicks creats enough friction to begin the initial warming stages. You might say you are fooling the engine into thinking that its not as cold as it thinks.

The jetting WILL change when modifying the cylinder or compression. Get it running, do a WOT plug chop and work your way from the main to the needle adjustment, down to the pilot and mixture screw. I have run both a stock rejetted carb and an FCR40 on my 628. the stock carb made the bike run like a tractor compared to the FCR! haha.

I did a JE high comp 100mm piston, hotcams stage 1 and ported cylinder head. I broke it in and ran it for a couple months with the stock carb (rejetted), I then put on a fcr40 from an 07 crf450. The FCR carb really opened up the power on the bike, I think the stock carb is really a HUGE restriction on these motors. My bike starts 1st kick Cold and First kick HOT... Its not rocket science getting it to start properly, you just have to be patient. I spent many hours tuning the carb, changing jets needle position and then doing it again... and again.

Im my opinion the FCR swap is definately worth the money. I spent about 300 dollars on the swap, I even bought a crf clutch lever and am using the hot start. I dont see too many people setting up the hot start on their XR, I dont know why, it helps tremendously after a dump or in really hot conditions.

Good luck :)

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