xr650r needle???

i am trying to find out if i have the right needle in the bike or not. the bike was purchased from a buddy who said he did the hrc kit to it but the bike really isn't as fast as other people are saying it should be. i.e. people lifting the wheel in first through third by just rolling on the throttle. it won't come up in any gear without a quick snap of the clutch and it has a bad stumple in the middle when i romp on it. so i tok the needle out and it reads b53e on it. is this the stock one or hop up needle. also i noticed it was at the second position from the top and i read it should be in the third. hopefully it is the right needle and just moving the clip down one will fix my problem.

The b53e is the hop up needle. The clip position depends on your altitude and temperature, but the 3rd clip position is very common for altitudes under 3K feet and temps below 80F.

On pavement especially, your front wheel should be able to pop up fairly easily with just the use of the throttle in 3rd. If not, then something is wrong. Get your jetting sorted out and then check the valves to make sure they're properly adjusted, etc. If worse comes to worse, find out how much leakdown their is when the engine is both cold and hot to check the health of your engine.

Look at the whole picture when jetting. 68s to 70s pilot, you have the right needle, 175~178 main for most like it was said.

Altitude and temperature and humidity. Air filter, making sure that the carb intake boot was changed, both air box pop outs were removed, holes in the side cover are cool for some. Smog pump removed and capped. Intake vacuum port plugged. Float level at 16mm ~16.5mm. Exhaust muffler tip being a HRC or stock tip drilled out to 2".

Tons of info here: http://www.xr650r.us/

Making more horsepower Here: http://xr650r.borynack.com/

Between the two of those links you will find a ton more.


All About the XR650R


yea i pretty much had all my bases covered. it runs awesome once i get it up top but in down low to the middle it stinks. hopefully the needle will cure the problem. it does have the airbox cutout also which he did cut alot of holes it seems. not really sure if it matter how many holes you cut but he cut a bunch.. i have a 175 in the main i am going to pikc the next size and try that to but it definately seems to be a needle position setting. when i got the bike is also had the 65s jet but i already changed that to the 68s but it didn't really make a difference.

as far as the leaddown test is concerned i am pretty sure the motor is great. i bought it used frfom a friend of mine who only wore out one tire with the bike and that was all street miles. so i would say it has 1000 miles on it

Sounds like the bike doesn't have a lot of hours on it. Still, make sure the valves are properly adjusted as they can affect your performance.

After you change the clip position, check to make sure your fuel screw is properly adjusted as that can affect your off idle snap to some degree. See how she runs like this, then cover the airbox holes with duct tape and see how she runs with the holes covered.

Are you running a stock header and cannister with HRC tip or ???

stock header and silencer with hrc tip

I ran mine with the B53E needle in the 3rd or 4th position, 68s and 175 pilot here in Florida. It ran a tad rich but it was relatively smooth throughout the RPM range.

The thing is that the stock carb doesn't have instant throttle response. Thus the popularity of aftermarket carbs like the Edlebrock and Mikuni TM-40. I use a Mikuni TM-40 from Sudco.com. Save your $ for one of these, it will make you happy.

Adam, just by looking at the needle w/out the stock one side by side for comparison you won't be able to tell. I'm not sure if there is lettering on the needle like jets have. The 172 main jet works well for me, not too lean not too rich. Throttle response was right there. If I was to ride sand all day I'd go back to the 175 but it was a tad rich. You still have the stock air filter in there?

the needle does have lettering on it like a jet does. and i am using a uni panel type filter. i am going out to work on it as i type this so i will report back in an hour or so with an update

i moved the needle up a clip and that definately helped a bit. i turned the air screw out some more. i have it at 2 and 3/4 out.. i guess maybe the 70s is in order, anybody have a part number for that one? i also covered up the holes in the air box which seemed to help a bit. i think this guy just put to many holes in there. i will ttry to post a pic of it later. the one thing it still does it it still sputters in the middle a bit, definately not half as bad as it was. i wonder if it is to rich and it kinda stumples on sudden throttle then catches up to itself.

here is the pic of the side panel


When I had the 68s pilot jet and midified side panel my bike had a HUGE flat spot down low. Once I went to a 70s and tuned the fuel screw it ran great. I found my bike liked the B53F needle which is supposed to flow even more fuel than the B53E power up one. If your bike needs that much more fuel you may need to increase the main jet size.

i got the fuel screw way out so i am going to try and go up a size on the pilot. i need to run some errands anyways today so i will stop by the bike shop and order some more jets up.

I didn't know your sidepanel was modded like that. You'll need at least a 175 main jet and a 70s pilot to get her running right.

i found a picture of a xrsonly modded side panel.


seems to have way less holes then mine does. could it be possible that the previous owner actually went overboard on the holes. maybe i should buy a new sidepanel and make it look closer to that picture on xrsonly

almost forgot to give ya the jetting update. i have had the best luck with 70s one turn out fourth clip on the needle and 175 main. i may go back to the third clip on the needle to see how that it but i think i got it as square as it's gonna be. still have a dead spot but i seem to have minimized it. i will probably go back down tot he third clip but all of the settings i tried took about three hours.

settings i tired that didn't work.

70s 2 turns third clip, 180 main

70s 2 turns fourth clip 180 main

70s 2 turns fourth clip 175 main

70s 1 turn fourth clip 175 main(current setting) when changing from two turns to one turns it helped the dead spot a decent amount so i am thnking maybe the needle is kinda now bleeding over and affecting it. i kinda changed to many things at once sometimes so it was hard to tell what actually worked. i do know the 175 main is for sure what i need caus that had way better performance then the 180.

Where is the dead spot at?

With the needle, you can fine tune it by adding very thin washers below the clip to set its height between clip positions if needed :crazy:

Sounds like you were lean/flat on your early posts leading to a slow feeling bike.

Though where you are now a slightly rich main usually gives you a wicked mid hit,and most people don't ride around at full throttle so it works,BWB680 may be an exception i've seen his web and photo's WFO all the way ..

I want to change from the 3rd clip to no 4 on my needle,just for a test but that flippin gasket on the top of the carb seems bigger each time i am in there,and it only just fit last time.

i hear ya on that gasket getting bigger. the weather is pretty bad around here lately but i am pretty sure this is where i will keep it. if i only road off-road i probably wouldn't even notice but on the road you can really use all the power you can get.

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