as the title says, AFH code lump, CBR600 carbs with jets drilled out to 150 (the guy who drilled them didn't have a 148 bit and assured me the difference would me minimal) running on a facet pump with pressure regulator set at around 2 psi

sounds like it's getting too much fuel? it will start, idle ok for a few seconds, then the revs pick up until it sounds like you're ragging the nuts off it, then slowly dies, guessing it's too rich maybe but the mixture screws are wound right in, don't think it's fuel starvation as it doesnt sound like it's hunting

really need to get the car running as no car means no work, and i'm skint at the mo :(

any ideas?

if its revving without any throttle its most likely that you have a vacuum leak.

check, check and check again.

i started mine this week with jets drilled at 150 and both mk3 fuel pumps going and found it overfueling and coming out every breather so unplugged the main pump and its fine ,on the carbs and I've got [cbr 600]my mixture screws 2 and a qaurter turns out ,air leaks are big thing when it comes to bike carbs ,also make sure your carbs are roughly balanced ,what about the idle wire/cable is this working correct,did you blow out and clean all jets and make sure you float jets work?

mine's running on the lift pump from the tank and a facet "purgolator" or something electric fuel pump in the engine bay, with pressure regulator

pressure set at roughly 2 psi on the regulator, so it doesn't spray fuel out the top of the carbs like it used to

mixture screws on mine are about 1 full turn out, might whip them off tomorrow and wind them out another 1/2 turn to see if it makes any noticeable difference but i've got the feeling it's still overfuelling

did manage to drive it today though 200m then the facet pump went dry so i'm guessing there's not too much fuel left in the tank

so tomorrow i'll stick some more petrol in and try winding out the mixture screws a bit more

revs don't pick up quite so much on their own anymore so i think i may have sorted (one of) the air leak(s)

i hate the tinkering stage, you spend all that time and effort ripping the old lump out, carefully sticking the new one in, woking out what goes where, making things fit where they shouldn't and then you just get stumped by something that normaly turns out to be some stupid little thing that you really should have realised weeks before hand

i no were your comming from it took me 2-3 hours to get the throtle cable [bmx brake cable :-D ]on with a return spring,setting up is ag and air leaks too

but mines running on a 1.6 8 valve with just the in tank pump [no facet or regulator] and I've not noticed any fuel starvation ,even gave it its first bypass trek today ,so great going from a 1.0 4 speed to 1.6 5speed and the carb noise is awesome :-)

good luck and get tinkering

i no were your comming from it took me 2-3 hours to get the throtle cable [bmx brake cable :-D ]on with a return spring,setting up is ag and air leaks too

but mines running on a 1.6 8 valve with just the in tank pump [no facet or regulator] and I've not noticed any fuel starvation ,even gave it its first bypass trek today ,so great going from a 1.0 4 speed to 1.6 5speed and the carb noise is awesome :-)

good luck and get tinkering

What have you put this into? Also, what gear box are you using? I've heard that the standard 5 speeds are a little soft for the additional torque produced by the engine/carb set up. I'm in the middle of a similar build myself

ok so i made a mistake, there is no lift pump in the tank and no pump under the car so it's only running on the facet pump

it's still massively over fuelling, pressure set at around 2 psi, mixture screws 1 1/2 turns out

is it the jets? i really hope it's not :(

if it is the needle what size would i need to go down to? found someone in the UK that supplies them in various sizes at £3.50 each

any ideas of what else it could be? i'm completely stumped

also noticed a wierd electrical fault last night, when the lights are on, if you turn on full beam and then turn it off again, as you pull the stalk back to click off high beam, the fuel pump turns on!? fuel pump is wired directly to the ignition live just behind the barrel and i can't see anywhere that the 2 wires (fuel pump live + high beam) could be connected

starting to get really down about this now, no job, no money, no car, no idea how to fix it :(

Edited 12 December, 200916 yr by skapunk1

ok so i made a mistake, there is no lift pump in the tank and no pump under the car so it's only running on the facet pump

it's still massively over fuelling, pressure set at around 2 psi, mixture screws 1 1/2 turns out

is it the jets? i really hope it's not :(

if it is the needle what size would i need to go down to? found someone in the UK that supplies them in various sizes at £3.50 each

any ideas of what else it could be? i'm completely stumped

also noticed a wierd electrical fault last night, when the lights are on, if you turn on full beam and then turn it off again, as you pull the stalk back to click off high beam, the fuel pump turns on!? fuel pump is wired directly to the ignition live just behind the barrel and i can't see anywhere that the 2 wires (fuel pump live + high beam) could be connected

starting to get really down about this now, no job, no money, no car, no idea how to fix it :(

no luck then? can you not turn the pressure down? poss worth running the pump through a relay although not to sure.I've not changed my needles at all ,were can you get the needles i no a local firm from me that do main jets at 3 quid each but untill i get to rr il stick with 150.

just had a thought can you not lower[lean] the needles with a circlip adjustment like r1/r6 carbs? just a thought undo the top black caps hold coz theres a spring underneath and check diaphrams and the needles for adjustment

i no were your comming from it took me 2-3 hours to get the throtle cable [bmx brake cable :-D ]on with a return spring,setting up is ag and air leaks too

but mines running on a 1.6 8 valve with just the in tank pump [no facet or regulator] and I've not noticed any fuel starvation ,even gave it its first bypass trek today ,so great going from a 1.0 4 speed to 1.6 5speed and the carb noise is awesome :-)

good luck and get tinkering

What have you put this into? Also, what gear box are you using? I've heard that the standard 5 speeds are a little soft for the additional torque produced by the engine/carb set up. I'm in the middle of a similar build myself

hi this is in a mk3 now

mk3 cl 5 speed box and mount

abu 1.6 golf engine ,flywheel and clutch, mk3 release bearing

standard exhaust cat internals removed

cbr 600 carbs 150 jets

its fun not super fast yet

fast enough for mk3 with 1.0 brakes :-)

il work out how to put pics on here soon as soon as I've sorted and tickled it up some more cheers

i've tried the pressure all the way down to 0.5psi or thereabouts, it does seem to run a bit better at around 1, 1.5psi

how would i adjust the needles? not to good with bike carbs so not entirely sure what i'm doing

needles are from wemoto.com

mine are drilled out to 150 at the minute but it just seems like there's way too much fuel going in, really bad throttle response and it dies quicker if you try revving it

got an air suspension setup for sale so i think once that's gone i'm just going to get it towed to the guy that does the RR and see if he can sort it because i've had enough of the fucking thing

i've tried the pressure all the way down to 0.5psi or thereabouts, it does seem to run a bit better at around 1, 1.5psi

how would i adjust the needles? not to good with bike carbs so not entirely sure what i'm doing

needles are from wemoto.com

mine are drilled out to 150 at the minute but it just seems like there's way too much fuel going in, really bad throttle response and it dies quicker if you try revving it

got an air suspension setup for sale so i think once that's gone i'm just going to get it towed to the guy that does the RR and see if he can sort it because i've had enough of the fucking thing

perhaps the jets are too big?

not sure if the cbrs needles are adjustable? but definately interchangable mikeymk used 900 needles in 600 carbs ,are the butterflys balanced? are they t eed off so they have slight pressure then returned to the tank

for all i no they need next to no pressure compard to injectors or spi

also wemoto is only along the road from me :)

Edited 12 December, 200916 yr by bmwe30init

come on guys, anyone got any other ideas? really stuck and i need the car running asap

Cant see the jets being too big, Bogg's told me to drill my R6 jets to 1.65mm.... for 1.6 8v....

Cant see the jets being too big, Bogg's told me to drill my R6 jets to 1.65mm.... for 1.6 8v....

really? i did think it felt slightl restricted i might try 1.60mm and see how it goes.

anyway back to helping ,definatly no air leaks as when i had one it sounded missy and fuel pissed out of the vents ,i think you need to maybe find a motobike fan who nos about carbs friend or family? where abouts are you ?

i'm in kent, and noone i know does any of the mechanical stuff to their bikes, they just ride them, and all the local bike places i've been to won't touch it because it's a car :(

no air leaks that i can think of, checked the obvious places and all seems ok, and the revs aren't picking up anymore so i don't think it is an air leak

also, since adjusting the mixture again (wound it out to 1 1/2 turns after you described your setup) i've got next to no throttle response now so it has to be fuelling, will whip the carbs off AGAIN today :mad: and wind the mixture back in again to see if i can lean it out a bit that way

trouble is i don't think it's the actual fuel/air mixture set by the carbs that's the problem, so leaning it out using the mixture screw wont solve the problem, just cover it up slightly

i want to find the cause of all the aggro so i can take a fucking great hammer to it :mad:

still got no idea as to why my full beam turns on the fuel pump either

Edited 14 December, 200916 yr by skapunk1

Sounds like you av covered most things, maybe your pump or reg are faulty... happens even on new gear....

fuel regulator is the next thing to check, just need to find someone with one i can borrow, it was a cheapy one off ebay so didn't expect it to be too good, did expect it to work though

I jus run the bike pump, no need for reg then as its built in.... might be worth changing over if you cant find another reg to try...

will keep that in mind, thanks

any other ideas?

right, changed the jets today because i'm convinced it HAS to have been the jets as even with the mixture screws right in and running on 1 PSI pressure it was still overfuelling

now has 134 jets in and it starts/idles a lot better with the mixture screws 1 1/2 turns out with 2 PSI pressure but can't tell if it's over/under fuelling now, still very little throttle response (although better than it was with the 150 jets) and won't idle for very long (maybe 10-15 seconds)

going to change the HT leads later as one of them is a bit dodgy, and reset static timing but other than that i can't think what it could be other than the fuelling being way out

with your static timing set, and the dizzy set to max advance, and idle screws turned 1 1/2 turns out it should start and run properly. Vac leaks will cause it either cut out on idle or rev highly.

your electrics sound like a mess too mate, where did you wire your fuel pump off? did you have problems before?

Wire your fuel pump with a fused wire off your coil, or power both your coil and fuel pump from the ignition switched live.

shouldnt have any worries with your full beams coming on.

check for vac leaks, check again and check again.

also do you have a fuel return?

have you blocked up any unused holes on your carbs that could be letting excess air in.

also when you start the car up from cold, you make need the choke on for 30 seconds and then it should be fine.

new HT's are a good start, it may be worthwhile swapping out the dizzy for another known working one

electrics are a mess, previous owner has wired pretty much everything to something else, there's a swith on the dash to turn the rad fan on

wiring for the pump came off the ignition live just behind the barrell so i can prime the carbs before switching to the starter motor but never had problems with the lights before (except the spot lights the previous owner put on, which came off the day after i got the car) and it's only when you turn the full beam off, if you hold the lever after it clicks the fuel pump runs, but when you release it back to the dipped beam position the pump goes off?

HT leads are new, but i broke one of them when taking it off so i'll replace that one

and just to doule check, static timing is:

turn engine until timing marks on cams line up

pop cap off dizzy and turn until line on rotor arm lines up with small line on dizzy casing, have i got that right?

dizzy came off a sweet running breadvan i broke not too long before taking the dizzy for the conversion so i know that's working ok

the only lines on the carbs that haven't been blocked are the big ones either side which i assumed were coolant lines for carb heating, could this be the problem? if so i'll have to go back to the barn and try and find the plastic bit i took off one side, which could take a while

thanks for the help

oh and fuel lines, yeah it's got a return

fuel is currently running from tank to pump, then pressure regulator, then back to the tank through the return with a t piece going off to each fuel feed on the carb like this

Edited 17 December, 200916 yr by skapunk1

So from that picture i assume your reg is after the pump, but before the carbs.

ideally you want two t-pieces, so there is only one take off to the carbs from the main loop. from that take off you would fit another t-piece and fit those two lines to the carbs.

static timing! no no no!

lol. the cams will turn twice for every one revolution of the bottom end, so you need to check TDC in a couple of ways.

mark on the crankshaft pulley, notch in flywheel through the top of gearbox, or popping a Very long screwdriver down spark hole no1 (nearest crank pulley) and turning the engine until the piston is at the top of its travel.

then get your dizzy and whack it all the way to full advance.

have you got a pic of the holes you haven't blocked off? which side of the butterfly are they on? they only holes on mine i haven't blocked are for waterways, as they are post 94 fs/ft cbr600s