I have just about had it with my carb. Although the bike starts consistantly well, it runs flat in the midrange, enough that I have trouble carrying a wheelie because the power drop often brings the front end down fast. Also, it hesitates at low throttle openings (lean I suspect). The motor is "uncorked" motor I am running the following stock carb settings: 68s pilot, 178main, 53E needle in 4th position, float level at 16mm (now less to minimize bogging on the face of jumps or big whoops) This problem is made worse with an opened up airbox cover (too lean). My next step is to try the 70s pilot and maybe raise the needle to the fifth position. Am I in the right ballpark? What is the general setup for 650R riders out there? Thank you all for any tips. Adam
If you run out of gas in your float bowl, you'll lean it out. You'll want to go back to stock on that, and find the root cause for your bogging. Pull the plug to see if your rich or lean. Use the choke if you think your lean, if it runs better with the choke, then you were lean. Jon
Hi Adam I think my jetting is good for almost every stituation. The only place I don't like is in tight single track. Lugging it in second gear often results is stalling. But I don't ride single track that often so it's not that big of an issue. The mid-range, however, is very good. And the top end has more than enough! I certainly haven't experienced any bogging on jumps or through whoops. Here is my set up; -Uni-filter, with stock airbox -Comp. exhaust tip -Comp needle in middle or 3rd position -68S pilot jet -172 main jet I have looked at the float and the air screw but don't know what they are set at. But I believe the settings, if not stock are very close. I don't really know what to recommend for you. But I would certainly let you try my bike for comparison. Brian
Thanks Brian. I otherwise love the bike so I will persist with this carb. I will change the carb closer to your settings and use that as a reference point. Riding time is unfortunately limited as wife is 8 1/2 months along. Brief outings well within cell phone range are all thats allowed. New riding buddy coming soon!
mine Low. This bike will lurch if the throttle is not rolled on and it is especially prone to this lugging if you have just let off the gas. Worse if your idle is below 1000 rather than the seemingly high 1400. The offidle enriching circuit is to blame but plugging its intake with silicone or a 5mm hose length will create more back firing than many prefer. This does help the rollon from idle, though I felt it unnecessary - off throttle this mod enables more engine braking than the current 2stroke backpressure. Top. Ensure the needle mechanism hidden inside the upper carb is not worn when disassembled - my arm and spring combo connected to the needle barrel wore itself larger pin holes which dropped the needle action a clip or two at wide open throttle tension. Float level can be 2mm lower than stock but I have not needed it - other than to control fuel overflow which seems common to my 650r. This time of year I run 178, 68s, 2inch drilled stock tip, no airbox snorkel, opened side cover, stock filter, b53E fourth clip. Mine starts well if I turn it to Reserve avoiding the choke, but my idle is 1000, the float overflows, everything is opened wide and running on 87 or 89 Sunoco (10% alcohol). Consider removing the flap on the choke plate for smoother flow. Ensure you do not have the fatter b53F Canadian needle? Ensure you changed/modified the manifold between the carb and engine? Ensure the choke flap arm is down rather than forward. Ensure you have the 68S. Check your fuel screw is not out more than 2 turns as it can disguise all circuitry setups. Ensure the manifold clamps have a 12mm gap between their tabs - I add a sealant under the manifold as it is air-gap heaven that may only suck after midthrottle vacuum. PM again if you are near the GTA. Hope its a dirtbiker on the way. http://www.xr650r.us/jetting/.
Hey Valdez, I wonder if you still have your 650? I need some help with mine, just finished the engine and now I need to get it set up for the new stage 1 cam, I took it to the Honda dealership in Markham but it came out worse from there backfiring and not idling properly. I forgot what jet and needle set up I did back in 2012 Anybody knows a good shop to do this for me?
