Not the eating kind the motorcycle kind. What would cause a bike to stumble only at a certain RPM? Granted this is on my Hawk GT & not the VFR but it's a Honda & I park it next to the VFR. The symptoms are a hesitation/stumble at 6800RPM-7800RPM at seal level to about 300feet (South Jersey) & the same thing at 5200PRM-6200RPM at 4500MSL-6000MSL (Blue Ridge & vicinity). It feels just like the bike is running out of gas. I checked the plugs & I'm putting a new fuel filter on it tomorrow. Any thoughts? I admit fully I don't know squat about carbs. KC-10 FE out... lane:
Do you rev it higher than 7800 and it gets better? If no, you might have a leak (vacuum, or post carb through manifold) somewhere and the high RPM velocity makes it worse. If yes, well that blows that theory.
It seems to have a slight hiccup up to those RPM's & then has the very pronounced stumble, then smooths out above that. Since it's just about at redline after the top of the stumble, I've usually shifted by then. It's rideable, but annoying & slightly dangerous since it happens right where normal shifting takes place. KC-10 FE out... lane:
If it sounds like it is running out of gas, it probably is. Like Vlad said, vacuum leak or jets dirty. You could have a plug or coil breaking down at higher rpm. Don't park it too close to your VFR, it may be contagious!!!
sounds like time for a clean & sync; could take out float drain screws & shot carb cleaner up into each hole. Thats kind of a might work thing but probably not.
Thanks for the tips. I have to work this weekend so I probably won't have time to take the carbs off & clean them until Mond or Tues. How does one determine if a carb is jetted correctly? The bike had the full TBR system & uni-pod air filters when I bought it. Now it has the full M4 & the stock air box. I never did anything to the carbs after I made those two changes. After I clean the carbs up, how do I go about determining if I have the correct jets? The previous owner gave me two jet kits so I have plenty of parts to work with. Thanks Again KC-10 FE out... lane:
