is it ok to do.... i read that if your fuel pump goes out you can bypass it.... has any of you done it?

 

if youre talking about the f3 the bike will run with out a pump as long as gravity can fill the bowls in the carb , so basically the bottom of the tanks would need to be higher than the carbs

 

Ugh, I'm trying to get the pump on my F4i to run and it's being an unholy bitch. Seriously, I'd rather **** a bear trap than ever have to deal with this again.

 

yeah its on the f3... i cleaned the carbs and it still was acting up.... i read that the airbox needed to be on there good with all the screws so it could withstand pressure, and if its not sealed it can cause problems similar to the ones i'm having...so i made sure it was on good and had to find screws, and still the same problem..... i took off the stock exhaust and put on a tip so i thought that might be the problem, so i put on the stock and i still have the problem.......
3rd gear and up the bike boggs and practically dies, i can open the throttle all the way and it will do nothing... if i barely give it gas it will stay the same rpm... if i down shift to 2nd or pull in the clutch it will rev all the way up....

so now i think my next step is the fuel pump.... i'm gonna try to bypass it and see if that works ......

 

99% of the time it has nothing to do with the fuel pump, and something to do with something else electrical

Since the bike is FI, just about any fault in a sensor or wire will not allow the fuel pump to run, it's a safety feature...

check relays, and wires.. Most the time its a pinched wire or a wire pulled from a plug...

 

+1 ive had probs w/ my fuel pump relays in the trunk area. broken wire, also one of the relays stuck and the pump wouldnt prime. then there is always the red switch, if you have a prob there the pump wont prime either.....

 

i know my f3 is not FI but in the service manual for the fuel systems troubleshooting says a symptom of misfiring during acceleration is caused from the icm(cdi) stops ignition intermittently to prevent over rev (rev limiter malfunction) ......
that might be whats wrong with my bike....

 

Vaccumme (sp) line maybe?

 

whats that?

 

well one way you can know for sure, is to simply run a couple pieces of wire from the battery to the fuel pump and see if it turns on.. If it does you know the pump is good
Then use a multimeter to make sure 12v signal is getting to the wires coming into the fuel pump.. Usually a bike will only kick the fuel pump on for 1-3 seconds when you first turn the key on.. Then it doesn't run until the pressure drops

 

U might not be jetted correctly,try jettin it to run richer,I know it's totally different but on my old 2 stroke dirt bike,just before it stalled out cause it was runnin outta gas(when idleing) the rpm's would climb really high then it would bog and stall.Just another suggestion to think about.

 

i just pulled the plugs out.. im lookin at them and they dont seem to be fouled.... there are 2 ngk and 2 autolite plugs that were in it.. i dont think that would hurt anything though.....they are dirty but kinda white looking... does that mean its running lean?... but im gonna get new plugs it it in the morning.......
hope this fixes my problem..... im tired of taking this bike apart..lol

 

yes white is lean,black n wet is rich,they should be the color of a brown paper bag if it's running right.sounds like your gonna need a jet kit to get more fuel goin through it.just gettin new plugs probly wont fix it.

 

what size jet would you recommend...carb #1 & #4 use a 135 and #2 & #3 use 138 for the main jets.....should i try adjusting the mixture screw before i buy a new jet kit....
if i buy an new jet kit how hard is it to get tuned up to a tee?

 

Blee didn't this happen to villa's bike? It had low end power but no top end.

 

not sure if this will help but on my f4i the fuel pump stopped working so i replaced it and it still didn work,replaced wiring harness and relays still nothing it ended up being ignition switch there is a diode in the switch that goes out and it will still turn on everything but the pump (fan,starter,etc..) i replaced key switch and it was money..hope this helps

 

Honestly I havent tuned a sportbike,but if the carbs are set up the same as a dirtbike then,you have 3 different jets that serve 3 different purposes,pilot jet...main jet...needle jet...
Dont quote me on this.. but this is what I think I remember
the main jet is for Wide Open throttle jetting.
the pilot is for low rpm jetting
the needle is for mid range jettin

ah forget it, dont listen to me,I can't remember,I haven't fucked with carbs in many many years.I'm goin off a very foggy memory.I could be totally off,someone will post who knows carbs real well.

 

I think so but I'm stoned right now and can't remember ****

 

i dont get it!!! i still have the same problem.....
it will take off fine thru 1st & 2nd but as soon as i get it into 3rd it just boggs and has no power(practically dies).... i cant figure it out.. anyone had this problem...
iv taken the carbs off twice and cleaned them and the jets and passages, put in new plugs... ran thru all the troubleshooting in the manual......i had a R1 that had the same problem but i sold it before i found out what it was.....
any ideas?!

 

is this bike full fairing or street fightered and did you change any thing right before it started running bad ?