I recently got caught in the rain heading home from work. Bike had no issues making it home but when I went to start it the next day it sounded like a 250! My first thought was water in the gas so I drained the tank. After putting some fresh gas in it ran fine for 10 miles or so and then started acting up again. I have since changed the plugs and redrained the tank but still have a misfire from idle to 4-5k rpm. Anything above that and she's normal. Anyone have a similar problem? Bike is stock except for a slip on exhaust.

 

Did you change out the filter? Also, check the injectors.

 

Haven't checked either but I did hear that the fuel filters don't let water through so that'll be my next step. What am I looking for with the injectors? Measuring voltage?

 

Did water maybe get into some electrical connection? WD-40 is good for displacing moisture. You might try unplugging a few things and spraying a little WD-40 in them.

 

F4i's are well known to not have waterproof electrical connectors. Someone at honda should honestly be fired. Anyways I'd bet large sums of cash thats your problem.

 

As for the injectors, this is kind of what I was think...not sure how relevant it is. Probably a long shot but here it is.

"CAUSE OF FAILURE 3...injector coil windings overheated from cooling system failure or ignition failure, with windings losing their magnetic performance; open (broken) windings; shorted (grounded) windings; seized pintle from internal injector corrosion (engine has set too long without running causing the injector to rust internally, petrol contamination with water, or cycling of injector without fuel flow to act as cooling agent and lubricant).

EFFECTS OF FAILURE 3...(A) If injector pintle is "off" the seat...overfueling of affected cylinder with resultant underfueling of remaining cylinders within "closed loop", poor engine performance, poor fuel economy, possible O2 sensor damage, potential engine overheating and engine damage, hard or no start, fuel leaks after shutdown. (B)If injector pintle is "on" the seat...underfueling/no fueling of affected cylinder with resultant overfueling of remaining cylinders with "closed loop" system, poor engine performance, poor fuel economy, O2 sensor damage, engine/piston/ring damage."

 

I decided to pull off the tank and spray the electrical connections w/ some wd40. Unfortunately it doesn't appear to have helped at all. I did however notice that the problem seems to be intermittent. It'll run smooth and rough. I'll try and get a video up tomorrow.

 

You sure the water is the cause and it is not just a coincidence?


I ride my bike to and from work in the UK where it rains ALL OF THE TIME, bike has never had an issue with it.

If you are getting water in the tank then your drain hole and tube (under the cap a little hole that runs through the tank and to a rubber hose below the tank is probably blocked.

How old is the air filter?

 

Not sure how old the air filter is but I know I personally have put approx. 9k miles on it. When removing the tank and airboz it didn't stand out to me as being dirty or aged.