Member Contributer COS_VFR Posted July 26, 2015 Member Contributer Share Posted July 26, 2015 I am running out of Ideas trying to solve a hesitation problem with my '96. It idles fine and comes off choke very quickly. In neutral, not under load it revs easily. But when I accelerate under load, once I get to about 4k, there is hesitation as if it is only running on 2-3 cylinders. I started with a dose of Seafoam when that didn't solve the problem, I opened up the carbs. They looked clean, but I made sure by spraying carb cleaner and compressed air through all the passages. The jets were clean. Next I replaced the fuel filter, bypassed the fuel pump, Left the gas cap open in case the vent was clogged, replaced the plugs, checked the resistance of the coils, verified the timing advance, synced the carbs, Used an unlit propane torch to check for vacuum leaks, Checked the exhaust can for obstructions, Since I live and ride above 6000 ft elevation, it usually runs a little rich, so I leaned out the idle, and then removed the washer under the jet needle. All with little to no change. Adding choke while accelerating had no effect Any thoughts, could it be the coils? any ideas how to check them under load? Link to comment Share on other sites More sharing options...
Member Contributer mello dude Posted July 26, 2015 Member Contributer Share Posted July 26, 2015 But when I accelerate under load, once I get to about 4k, there is hesitation as if it is only running on 2-3 cylinders. This!! You should be only under 4k in first gear, sometimes second in the local suburbs. After that, keep the revs up. its not a V twin. What your doing above is lugging it. Stop it. --- Your not the first.... Link to comment Share on other sites More sharing options...
Member Contributer COS_VFR Posted July 26, 2015 Author Member Contributer Share Posted July 26, 2015 But when I accelerate under load, once I get to about 4k, there is hesitation as if it is only running on 2-3 cylinders. This!! You should be only under 4k in first gear, sometimes second in the local suburbs. After that, keep the revs up. its not a V twin. What your doing above is lugging it. Stop it. --- Your not the first.... it does this in first gear from 4k to at least 8k and did not do this in the past. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted July 26, 2015 Member Contributer Share Posted July 26, 2015 Does it hesitate in each gear? Link to comment Share on other sites More sharing options...
Member Contributer COS_VFR Posted July 26, 2015 Author Member Contributer Share Posted July 26, 2015 Does it hesitate in each gear? In my test rides since I first noticed the issue don't think I have tried past 3rd. Perhaps surging is a better description. When I roll on the throttle at about 4k it feels like 1 or 2 cylinders are not firing. Link to comment Share on other sites More sharing options...
Member Contributer COS_VFR Posted July 26, 2015 Author Member Contributer Share Posted July 26, 2015 Does it hesitate in each gear? I guess I hit post before I answered that. It hesitates/surges in multiple gears, not just 1st, but I don't think that I have tried all 6. Link to comment Share on other sites More sharing options...
mcrwt644 Posted July 29, 2015 Share Posted July 29, 2015 is it jetted? Notched needles? If it is, this is your issue. That rev range in needle territory. Either drop the clip one on the needle, or raise it. Link to comment Share on other sites More sharing options...
Member Contributer burnes45 Posted July 29, 2015 Member Contributer Share Posted July 29, 2015 Have you tried 'Ethanol Free Gas' ?? If it is available near you give it a try. Tried for months to find gremlins at lower RPMs on my '97 tried a tank of ethanol free gas was like magic. I wont use anything else she runs so good on 'natural gas'. Good luck! Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted October 23, 2015 Member Contributer Share Posted October 23, 2015 I'm having the same problem. See my post "Re-jetting De-Californiaed RC36". It seems like a fueling problem but I don't have an answer yet either. Could be the coil, pulse generator, fuel pump. Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted October 23, 2015 Member Contributer Share Posted October 23, 2015 But when I accelerate under load, once I get to about 4k, there is hesitation as if it is only running on 2-3 cylinders. This!! You should be only under 4k in first gear, sometimes second in the local suburbs. After that, keep the revs up. its not a V twin. What your doing above is lugging it. Stop it. --- Your not the first.... Meh. The VFR is TWO V twins! I've had FOUR 4th Gen VFRs, all stock, spent tons and tons of time between 3k and 5k, and none of my bikes ever had that issue. At worst they got a little short of breath on Trail Ridge Road. Then again so did I! Sounds like a vacuum leak hasn't been ruled out under load. I'd think that changes more under load than ignition does. All that rubber is two decades old now. Has the system voltage been checked while running under load? Also anytime someone mentions running issues with a 4th Gen I like to ask if they've checked the secondary air filter. I didn't see anything in that checklist even about the regular carb air filter. If it's not a vacuum leak it could be time to freshen up the carbs - new needles, jets, floats. Remember that defects in the jets and needles that you can't see with your eyes can still affect atomization, etc. Then find someone with an EGA to help get the carbs adjusted when you button it back together. Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted October 23, 2015 Member Contributer Share Posted October 23, 2015 Good advice from Mello Dude. I don't know what you meant by "bypass the fuel pump" but you may want to check the flow volume of the pump. The service manual has a simple procedure for that. Honda wouldn't have written about it if it weren't important. Right now my carbs are soaking in Pine Sol. I'll update you when I'm done and let you know if the carb cleaning and replacement parts cured my similar hesitation problem. Link to comment Share on other sites More sharing options...
Member Contributer COS_VFR Posted October 24, 2015 Author Member Contributer Share Posted October 24, 2015 Well the it seems the solution was new float valves. After I replaced the float valves, the problems have been solved. Earlier, when I had the carbs on the bench and checked the fuel levels in the bowls, they all seemed correct. But there seemed to be a strong smell of fuel, when the bike was idling so I think that when the engine was running and the fuel pump was running, the float valves were letting excess fuel into the bowls. After replacing the valves the strong smell of fuel is gone and the bike runs fine. Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted October 25, 2015 Member Contributer Share Posted October 25, 2015 Fantastic. Good job. Link to comment Share on other sites More sharing options...
WGREGT Posted October 25, 2015 Share Posted October 25, 2015 Right now my carbs are soaking in Pine Sol. Really? That works? Doesn't hurt rubber parts? Did you soak it in 100% or 50/50 with water or what? Never heard of this before.... Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted October 25, 2015 Member Contributer Share Posted October 25, 2015 Yeah, I thought you were supposed to use Lemon Pledge. Or was that for lubing the chain? ;-) Link to comment Share on other sites More sharing options...
WGREGT Posted October 25, 2015 Share Posted October 25, 2015 Ha. Don't be silly. Who lubes a chain that comes sealed with lube IN it? Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted October 25, 2015 Member Contributer Share Posted October 25, 2015 Ha. Don't be silly. Who lubes a chain that comes sealed with lube IN it? Not after ya' use WD-40 to clean it... Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted October 25, 2015 Member Contributer Share Posted October 25, 2015 Original Pine Sol. Don't dilute Soak 24 hours. Remove all rubber parts first. It's as good as Gunk or better. Link to comment Share on other sites More sharing options...
squirrelman Posted October 28, 2015 Share Posted October 28, 2015 Most unfortunately, Honda chose to limit our access to idle mixture screw adjustments unless you obtain the special tool necessary. 4k rpms is near the high side of mixture screw influence, but still useful in tuning to reduce the OP's problem. Well the it seems the solution was new float valves. After I replaced the float valves, the problems have been solved. Earlier, when I had the carbs on the bench and checked the fuel levels in the bowls, they all seemed correct. But there seemed to be a strong smell of fuel, when the bike was idling so I think that when the engine was running and the fuel pump was running, the float valves were letting excess fuel into the bowls. After replacing the valves the strong smell of fuel is gone and the bike runs fine. Good news then !! Perhaps inspecting the spark plug color would have tipped you off to the over-rich condition sooner. After soaking (which is very seldom actually necessary, imo) it's essential that you set the carbs sideways and allow oil/lube to flow down into the throttle shafts. Last step in a proper carb cleaning ! Link to comment Share on other sites More sharing options...
Member Contributer MadScientist Posted October 28, 2015 Member Contributer Share Posted October 28, 2015 If we are talking about those GD D-shaped pieces of crap that are a total pain to get in the screw while you are burning your hands, then this is my advice to you: 1. Get/borrow the D-shaped bit 2. Remove the screws completely, or enough to access the whole head 3. Cut a nice straight line right across the head of the screw 4. Use flathead screwdriver bit to perform adjustments Link to comment Share on other sites More sharing options...
WGREGT Posted October 28, 2015 Share Posted October 28, 2015 I use one of these: http://www.motorcyclecruiser.com/review-motion-pro-pilot-screw-adjusting-tool-motorcycle-carburetors Works great. No burnt appendages. Buy it once, use it forever. Link to comment Share on other sites More sharing options...
Member Contributer MadScientist Posted October 28, 2015 Member Contributer Share Posted October 28, 2015 I have one of those... still works better with the flathead bit. Maybe it is better on a v4, but the bit slips out of the farthest carb on an I4 really easy. It's hard to isolate the torque on the screwdriver handle from the fixed portion and difficult to see or feel if the bit is actually engaged in the screw head from that far away. Link to comment Share on other sites More sharing options...
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