Went for a ride today, the weather was great. Had little issue 3 times while out. twice at around 45 mph as I cranked the throttle, it would start to take the gas, then cutout like it was running out of gas, for maybe 1/2 a second, then pick back up and go. Both times was accelerating through a turn when it happened. The third time was stopped at a red light. Opened the throttle to pull off when light turned green and started letting clutch out, and cutout again, almost stalling this time, then took off like normal. Nothing been changed on motor or exhaust in over 2 years.Did change plugs about 2 months ago, but been running fine. Has open mufflers, grampsized with K&N filter, and carb jetted 4 years ago. Dont beleive any of these are the problem because been fine till today. No backfiring, or hesitations noticed. Dont believe is ignition. Just like it ran out of gas. Any ideas?
Hey Rick. Sounds similar to what happened to me today. Not kidding! Were you in 4th gear? I was in fourth gear when this happened to me just like you're explaining here. The thing is I'm fine tuning the new carb I installed so I know I need more fuel since everything is new. As for you though, besides the sputtering and hesitation did it pop or backfire slightly on decel? How are your vacuum lines?
The other thing is that I have an HD tank on my VN800B Classic that was installed by the PO so I know its quirks already. Specifically, it has a variable rate flow tap that maxes out at a certain point and so as I was riding I just opened it up a little at a time until it stopped doing this. Sounds like you may be running slightly lean so it could be something as simple as a slight adjustment since you said you haven't had any issues for four years running now. Needles wear over time and the slightest changes cause fuel metering and atomizing issues so my first bet is on a simple adjustment of your pilot since you said you have such a good running record and this ONLY after ensuring your carb is clean. Sometimes the slightest loose fit on the airbox and housing is enough to offset things. Any cracks in the housing or anywhere else? I'm must giving you things I would look for if the bike were mine.
Have you changed fuel type or brand? I only ask that because mine seems to run better on Techron type fuels and if I can't find that I try QT. Don't know why but hey from what I've read the 800's are temperamental beasts.
Did you check the plugs yet to see how they look like? Sometimes, a CDI can cause this too. Did you wash it recently and get some water accumulation in the bowl? Have you cleaned out the bowl through the drain? Have you checked your float operation and fuel level? How is the rubber on the intake manifold? Is it cracked or loose? How is the manifold? The transition from carb to intake manifold needs to be sealed and pretty much airtight so that airflow metering is correct and the bike burns fuel efficiently based on your ideal settings that is.
Sometimes a hidden short in the harnesses or a faulty or loose lead on the IC's going to the plugs may cause this. Some will even say that if you have had NO PROBLEMS at all until now to just use some SeaFoam but I'm sure you already know that.
Since you said your bike's Grampsized is the crankcase vent hose still attached to your air filter housing? Sometimes that thing creates oil accumulation so severe that it may slightly impede performance like this and the fix is to just clean it since you have a K&N setup or replace the filter for those who are unable to clean their filters. What I did for this vent line was remove and run it to top left side of the radiator on the left side downtube, up around the front span across the spine through the harness hole, back down the right side downtube and attached a small inline fuel filter on the end as a trap. It helped mine breath better and cleaner. Another guy on here made a trap with PVC and placed it inside of his right side EPA cover area.
Give her a thorough inspection to ensure all is in order. Whatever you do please post back though because I'm interested in seeing what you find out to be the problem and how you resolve it since you have such a longstanding excellent track record with your bike.
You remind me of those few individuals who have a vehicle for years and they end up getting a new one from the manufacturer. Who knows? Contact Kawasaki and tell them how well you have been doing with your bike and maybe you will hit them up during a charitable time in their corporate image outlook and they'll give you a brand new bike because of your success!