Sign in to follow this  
Followers 0
UK Bosch

Made the move to the pig!

18 posts in this topic

I just sold my 2004 YZ450 with lighting kit and have replaced it with a 2003 XR650R as it's more suited to the kind of trail riding i do and doesn't mind a bit of road work to get there.

It's apparantly uncorked and has had the carb manifold changed and is fitted with a FMF powercore 4 full system but i must say i'm unimpressed with the power delivery. I thought it'd wheelie of the throttle at least in 1st and 2nd and be a bit of a handful but even in first it needs a tug on the bars to get it up? Sure when it gets going it's fast and the suspension is like a magic carpet compared to the YZ but i'm left wanting and keep getting wet because it won't lift the front through puddles.

Is this normal, have i been spoilt by the YZ450 power or is something amiss?

Has anyone ridden both the 650r and a 450 mx bike for comparison?

Share this post


Link to post
Share on other sites

You need to find out what kind of jetting is in the xr650r carb. to begin with.

Remove seat

loosen front and back clamps holding carb

rotate carb while in bike, about 30-40 degrees to the left side

remove 4 screws from float bowl, remove float bowl.

remove main Jet ( In center) remove slow pilot jet (towards front)

Read their numbers

You should have for general all around performance:

Main 175

Pilot 68S

If you don't have these then replace, go to your honda dealer for the pilot jet

This is a starting point....

Share this post


Link to post
Share on other sites

They don't have the snap of a 450 but if your gearing and jetting is good it will pull your arms off and make you pass out from the G-forces.

The gearing should be 14-47 to 14-49 at the least.

Mine came with a 13-47 It wouldn't let it use the tourque of the motor so it felt real slow.

Oh ya.. and a big nasty fresh knob helps too.

Share this post


Link to post
Share on other sites

Had someone follow me and it seems i'm spinning the rear all the time. damn it's hard to feed it to get traction. After about 40mph it just hunkers down clears off, it's like a game of dare to see how long you can hang on with the throttle open!

sorted the jetting and it'll now easily lift the front on 1st and 2nd off the throttle on the road but still can't float it over water on the dirt, this thing is heavy!

Share this post


Link to post
Share on other sites

There has to be something wrong...I have a 1995 xr600r with a half bald rear tire, a motor that smokes like its in a pulled pork bbq competition, I weigh 215 lbs and even sitting on the tank it will lift the front end over just about anything. Like you said it may just take a bit to learn how much throttle you need and exactly when to apply it.

Share this post


Link to post
Share on other sites
it's like a game of dare to see how long you can hang on with the throttle open!

haha, aint that the truth!!

I run 15X45 gearing and a quick snap of the throttle w/ a little tug on the bars at ~40mph (65kmh) in 3rd gear will stand this bike right up on the pavement.

On dirt however, this bike is heavy and has a ton of torque....if your tire is a little worn, its pretty easy to grab a handful of throttle and just break the tire (hence no wheelie)

It takes a bit of throttle finesse to wheelie this thing on flat dirt if your tire isnt brand new.... I find standing wheelies to be most effective for lofting the front across puddles and such.

Share this post


Link to post
Share on other sites
Had someone follow me and it seems i'm spinning the rear all the time. damn it's hard to feed it to get traction. After about 40mph it just hunkers down clears off, it's like a game of dare to see how long you can hang on with the throttle open!

sorted the jetting and it'll now easily lift the front on 1st and 2nd off the throttle on the road but still can't float it over water on the dirt, this thing is heavy!

Suspension? Set your sag and mebbe back off on the compression a bit while increasing the rebound- you want the bike to squat a bit under accel and stay there.

Share this post


Link to post
Share on other sites
Suspension? Set your sag and mebbe back off on the compression a bit while increasing the rebound- you want the bike to squat a bit under accel and stay there.

Yeah, you don't set up the BRP 's like an MX bike; it needs to squat under hard accelleration to get any bite. It has so much torque that it should be squating the rear end under full throttle. If the back end is at all stiff (rebound especially) it will just spin.

Share this post


Link to post
Share on other sites
Suspension? Set your sag and mebbe back off on the compression a bit while increasing the rebound- you want the bike to squat a bit under accel and stay there.

Yes...this is a big point! I had mine set wrong as well and the front was super heavy! Also resulted as the front wanted to track straight when going into corners at any and even mild speed...it nosed straight and was hard to steer! If the suspension is stock...set it up for yourself. (for correct Rider weight and valving) and you will feel like your riding a new bike!... http://borynack.com/XR650R/ has some good info on Forks and shock revalveing to get the correct setup if yours hasn't been setup for you yet!

Share this post


Link to post
Share on other sites

Right'o i'll check the suspension settings when i get back (off to the Alps for a week in the snow :smirk:) sounds like that may be part of my problem as many a time i've binned it trying to take a tight corner like i do on a 450 and it just wants to (and does) go straight on into a hedge. That said, on flat wide corners i find it so much easier to drift round than a 450, so much more controlable and a hell'ova lot of fun!!

The gearing is 14/50 and I only weigh a paltry 72kg. Thinking about it 1st gear is a waste of time and it'll easily pull away in 2nd so maybe i should drop a few teeth on the rear?

Share this post


Link to post
Share on other sites

14/50 is prolly an overkill with the gearing, if you cant pull the front wheel with that i bet its more than suspensions setting. You should have great acceleration and power with that gearing thru 3rd no problem. prolly drop a few in the rear since you say 1st is about worthless for sure

Share this post


Link to post
Share on other sites

mmmm...right, when i get back i'll give her a good going over as i've been pushed for time and only had half hour here and there. It's not slow, just seems...i don't know, lazy? To be honest the first time i swung a leg over i was breaking out in a cold sweat thinking the 450 is quite violent have i bitten off more than i can chew and after 5 mins i thought 'is this it?' Maybe because it's lower revs for the same speed as an MX and my brain still hasn't adjusted? It'll wheelie on tarmac no probs at all but i just can't lift it on the dirt no matter how hard i yank the bars, the rear just spins

Trelleborg rear btw

Share this post


Link to post
Share on other sites

Perhaps you are over-looking the obvious-sit further back on the seat before you twist the throttle. If traction truly is your problem, just sliding back on the seat so that your weight is better distributed over the rear tire should easily plant the tire and lift the front end to the moon.

My XR600 will wheelie in 1st, 2nd, 3rd, and will carry the front tire for a good distance in 4th if it hits a decent bump in the path, and I stay on the gas.

Your bike should have MUCH more power than mine so I don't understand the problem. Try sliding back on the seat some to see if that helps plant the rear tire. It is by far the easiest suspension adjustment you can make.

Share this post


Link to post
Share on other sites
If the back end is at all stiff (rebound especially) it will just spin.

Wait, wait- timeout! My (likely imperfect!) understanding is that you'd want less COMPRESSION (which will allow the bike to squat, transferring weight and therefore grip) to the rear. REBOUND though, you'd want STIFFER (or really, more damped) so that the suspension extends more slowly and keeps the weight on the rear. Am I messing this up in some way? (taken more from roadrace setups in cars, but the overall physics SEEMS like it should be the same...)

Share this post


Link to post
Share on other sites
less COMPRESSION (which will allow the bike to squat, transferring weight and therefore grip) to the rear. REBOUND though, you'd want STIFFER (or really, more damped) so that the suspension extends more slowly and keeps the weight on the rear.

Yes that's right, I have a mild understanding of suspension from my sportsbike days just havn't touched it on this yet. Compared to my MX bike which is like a pogo stick the XR is very soft

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0