hey man turns out the book doesn't have a spec for the fuel pump... only for the f4i... it does have this flow test it wants you to do when diagnosing a fuel problem? basically you have to jump a few wires and disconnect the fuel line to the carbs and check how much fuel comes out in a certain amount of time. you wanna give it a go? if so ill try to scan it or just type the directions out...

 

ill try it Stunt like i said at this point ill try anythin.My next step is a honda tech if i cant get this problem solved by this weekend.

 

well we'll try and not have u do that...

alright rmove your rear tail fairing and remove your tank mounting bolts. support the tank out of you way so you can remove the black fuel line that goes from the pump to the carbs. remove the two 8mm bolts on your pump so you can move it around. keep the supply line from the tank to the pump on. bend the black hose through the frame and put an empty water bottle or somethin you can gather the fuel in. On the sub frame on the right side find the 6 pin relay. this is the fuel pump relay.

Use a jumper wire and connect it between the black/white and the black/blue wires.

this basically jumps 12 volts to the pump...

make sure your kill switch is in the run possition
turn the ignition switch on and the fuel should start pumping.
*only hold it for 5 seconds then shut it off.
Multiply the amount of fuel by 12 to get the flow rate for one minute.
minimum rate is 700 cc or 23.7 oz.



if the wire jumping doesnt work. i found that the pump will pump fuel if you crank the motor... either way i think will work. but try the books way first.
if ur flow rate is less you need a pump

 

i looked in the diag section of the book for poor low speed performance:

• check for damaged intake manifolds
• check fuel flow
• check spark plug performance
• check ignition timing

 

thx man im off to the garage!

 

I have the same problem with my F4.

What I believe it to be is a major flaw with the F4.

The back story of the problem. Honda built the F4 to race. The battery is tiny, the charging system is weak, the radiator is small, and the fan draws all the available juice. The F4i is the same motor, but has nearly 100 more watts of charging power - or about a 25% increase.

On the race track I have never had the fan come on. The bike hits 2/3 temp and stays there. I keep the tack hovering at 10,000 rpm for 15-20 minutes with no problems. At speed the radiator is cooled by the wind, and the charging system is giving the battery full power.

In traffic, with no wind over the radiator it gets hot quickly. The fan draws enough power, and the charging system is so ineffective, that it literally does not have enough power to spark properly. It stumbles and fails.

So what can you do? Well - keep the revs up will help it charge. A bit impractical in town, plus it will heat the bike up more. You can change the coolant and make sure the radiator is as clean as possible... that will never hurt. You can also have your battery tested, as if it isn't in peak charge it won't work. What you can do is leave the bike on a battery tender over night.

What I'm looking at doing is replacing my R/R with one from a 05+ CBR or FJR, then see if I can retrofit the F4i stator into the F4. I hope to get as much of that 100 watts as I can.

This is the single biggest flaw with the F4, and Honda did immediately address it with the F4i. While it is annoying, knowing why it happens can help you avoid the problem.

 

r alot of f4'S HAVING this problem? im def. not....

 

Hey Woot, I completely agree with you! I have had my F4 for about 2 years and when it is hot and just after the fan comes on it will stall out off idle. I am a GM mechanic and have allot of know how on mechanical and electrical.
I have tested and replaced about everything to try and cure this problem. I even took it to a shop and he insisted it was in the carbs, so he overhauled them and he was WRONG!!!

I have replaced the battery, Voltage regulator,fuel pump and stator as of last month. I have monitored a meter while problem is accruing and like you said voltage drops off considerably down to about 11.2 volts when fan is on. As soon as it get's below about 11.8 volts it looses voltage to the coils and tries to stall until stator can catch up and give more voltage. So as you said I think it is also a major design flaw. Let me know if your fix works, they need more charging at idle. If I unplug my headlight all is fine but can’t ride around without a light!!

Brian

 

update.... i have checked , double checked, and triple checked everthing on this bike and nothing. I had bike sent to honda repair shop and here is there verdict and i quote from the honda tech"You need a new cdi module the f4 is known for having problems" so now i wait for the module if it works ill post if not this bike will be gettin traded in the spring.

 

you can take the fan off and clean it with eletric motor spray. a clean electric motor wont draw as much as a ditry one. or just change the motor completly to a newer one from a 600rr