16v on r1 bike carbs, fuel not getting through carbs

hi,

ive tried search but not found anything yet,

ive installed yamaha r1 bike carbs onn my kr engine, ive drilled out the main jets to 1.7
ive adjusted the mixture to 3 turns

ive got the r1 fuel pump fitted and it primes

fuel line is connected to the main brass fitting at the bottom of the carbs

i have spark

seems the fuel is getting to the carbs, but not to the engine,

ive tried gently blowing through the two t pieces at the top which pushes some fuel through to the carbs and also some carb cleaner which makes it try to fire.

so i presume there is a problem with the fuel getting through the carbs,

ive checked the jets at the front of the carbs, the floats move freely, main jets etc all clean and clear

what could be my problem here guys??

have i missed anything silly?

i will get some pics up of the installation later on

are there any breathers i should have blocked?

also i havent connected the vacum pipe from the ecu yet but it should atleast fire without this right?

appreciate your time

george

 

Have you tryed to use the choke on the carbs to aid starting, my carbs are setup perfectly but still can be difficult to start from cold. Failing that put some petrol into the inlet of each carb with the trottle closed so that it sits against the butterfly valve. Then when trying to start blip the trottle and see if it fires, if it runs poorly then the carbs are moast likely out of balance, however be careful as if it catches the engine revs can redline very easily from cold.

 

Was there any fuel in the float bowls when you checked? R1 carbs usually sit at quite an angle on the bike, so it could be the float level in the carbs is off depending on the angle you have them mounted. Possibly causing the choke system an issue with supplying enough fuel.

 

i tried fuel and also carb cleaner, (not the way you say though)it actually ran for about 10 seconds at one stage but i couldnt get it to do that again.

i had to drain a fair bit of fuel from the individual drains so i presume fuel was getting to the bowls

i also tried with the choke on too

im miffed

 

here it is

 

Well the angle is fine for the R1 carbs so that rules that out.
All the basics like ignition and cam timing checked and ok, got a good regular spark too?
Plastic breather suggests an ABF engine (could be 9A or 6A I suppose), are you using a KR dizzy as the ABF one only has one window for the hall sensor.

 

Are the butterfly valves fully closed? If they are slightly open there will not be enough vaccume to draw fuel at idle, when i say closed i mean closing untill the idle adjustment screw is no longer touching the leaver then wind it back in untill it just makes contact, then a half turn

 

thanks for the replies,

im glad the carb angle is good,
its a kr engine

timing marks are all correct

i have adjusted the dizzy to a point where it tries to start its best so i presume its round abouts where it should be as it doesnt get any better each way. i have a pulsing spark although not sure how strong it should be

1 thing i am unsure if i have an actual kr dizzy? will this make a difference?

 

i tried to open the butterflies a little when i was having no luck so i will make sure i close it next time i try it. thanks for that!

does this mean they should be started without use of the accelerator pedal in order to create a vacume to draw in fuel? how does it get air to fire or idle?

 

On a normal carb'ed engine there is an accelerator pump jet to overcome the fuel mixture going lean under sudden acceleration, so when trying to start a cold engine, you pump the accelerator, this squirts extra fuel into the cylinders to start, however mikuni carbs don't have an accelerator pump jet so using the trottle puts no addtional fuel into the mix

 

how fast does the engine turn?
i put CBR600 on a polo 1.4 16v AFH a couple of year ago.
i tried for a while to get it running and had similar advise that you have been given, dribble of fuel, ignition timing etc, but for some reason when i gave it a jump start off another running engine it started! but battery seemed to have been turning it over what i considered to be enough, but obviously not!

is it a constant fuel supply? pump the fitted right way round? from memory, is it two feeds to pump? one to prime and one to power constantly? check wiring at pump and ensure its 12v when the key is in the start position.

 

so they need to build up vaccum to draw fuel and fire, they get air from the idle jets right?

i'l give this a try 2moro with the butterflies shut and no pedal pumping see what happens
thanks

 

i charged up the battery over night as well as my booster, it spun quite quickly

theres a good point there too, il also check i get 12v on cranking the engine and not just when priming

 

Wasn't getting any voltage whilst cranking put a different relay in and now I have 12v priming but only .9v cranking,

The pump trigger pin was on theopposite side
Need a boost I think

 

got spark nice spark

got 12v cranking at the pump

fuel lines clear (pumps fuel whilst cranking into a petrol can,

bowls full of fuel

main jets all clear (blown through them)

no fuel comming out of carbs....

ran for 10 seconds on easy start with choke on before dying

battery and boosters on charge

sparks out and cleaned once again

carbs taken off for fuel to dry out if flooded by me messing about

deffo need to change the oil again after i sort this out.


any ideas guys this is driving me nuts... :wacko: :wacko:

 

If the spark plugs are wet or oily they may not be sparking properly when cranking and under compression in the cylinders.
Might be worth fitting a new set of plugs to eliminate the issue.

 

have u stripped carbs before fitting? Damaged or incorrectly fitted something? Have a read up on clubpolo theres some good info on there. Im humer on there. Is the ignition timing correct? U get spark but is it timed to 5 degrees before tdc or close to that? Im intrigued as you have the factors there for it to start.

 

something i have just thought of, how is the fuel pipe run to the carbs? Have you included the blue return pipe? If so how have you T'd it? This maybe your problem, top of T to carb, upright of T to the return. Have a play with the T's. I went to help a friend who had done everything and it had us stumped until we started fitting it from the beginning and altered the T's. Good luck

 

When it ran for 10 seconds did it run on all 4 cilinders or was it shaking about like it was running on 2 ? ,

did you use the trottle to try to maintain idle.

also when it stalled did it just stop or was there a cough from one or more of the carbs

When trying to start was there backfire from the exhaust?

 

jamez what is your ignition set to in degrees?