Trouble pulling away

i have a ZX9r which had been standing for 2 years , well i have it up and running now starts ticks over fine , but when i try to ride it ,wont pull away ,so strip the carb down changed all the jets and pilots clean all carbs etc , put all back together same things run fine above 3000rpm , starts ,runs fine ,go well , but just struggling to pull away ?? anyone have any ideas wont wrong ?

Did you change the plugs? Struggling to pull away can be down to failing plugs as the sparks may be too weak to properly ignite the rich mix.

aPetrol is a mixture of volatile fractions that evaporate at slightly different rates. While this has no effect if the petrol is left unused for weeks, leaving it for years can result in the lightest fractions evaporating and then the engine can lack power when this old petrol is used or even refuse to start at all. This old petrol in this state is called "stale petrol". Perhaps this could be the issue.

If you did not replace the petrol before starting the bike up but simply ran with what was in the tank I would drain it and give it a charge of fresh petrol just to rule out this possibility.

Is the engine stopping? My ZX6R would stall if I left the stand down, there must be a switch on it somewhere.

Bad fuel, dirty fuel filter, poor spark (plugs / Ignition), blocked air filter.

You say you have "changed all the jets and pilots".

Do you mean you have replaced them?

if so with what? Like for like?

You say you have "changed all the jets and pilots".

Do you mean you have replaced them?

if so with what? Like for like?

Yeah, good question, why change them ? They don't wear out . Only emulsion tubes , needles and slides wear out . What exactly do you mean by won't pull away ? Do you mean it doesn't accelerate how you would like it to or does it just falter and stall under load .

fuel has been replace , plugs are new, i have fitted a ivans jet kit , clean out carbs etc ,this was happening before i change jets and clean carb but the problem is still there !!

You say you have "changed all the jets and pilots".

Do you mean you have replaced them?

if so with what? Like for like?

 

Yeah, good question, why change them ? They don't wear out . Only emulsion tubes , needles and slides wear out . What exactly do you mean by won't pull away ? Do you mean it doesn't accelerate how you would like it to or does it just falter and stall under load .

Yes it falters and stalls have to slip clutch and rev it to keep it going above 3000 rpm it flys

Have you checked that the fuel lines aren't cracked or split?

i have fitted a ivans jet kit

A what?

I'm calling jiffy ignition - I reckon either the HT leads need a bit chopping off them or a coil is unhappy. Maybe even a duff battery.

Talk to Ivan. He charges enough. Bike should run properly.

I'd be looking at the pilot jets and the pilot air screw settings and while I was at it check the float heights and if you have carb drain nozzles , the actual fuel level in the carbs . I don't quite get why you are having to slip the clutch to pull away . How long have you been riding big capacity bikes may I ask ? You are in first gear I presume . Only asking because it sounds like you are trying to pull away in 3rd or 4th .

lol i have been riding over 40 years

lol i have been riding over 40 years

Same here , sorry, just checking. You get all sorts on here

Are the carbs balanced ok?

Inlet manifold rubbers ok,not perished or split?

Valve clearances ok?

Are they Cv carbs? Are the diaphragm rubbers ok?

I'd be putting the std jetting back in to eliminate that from the equation and get it running properly first.

So update gone back through the carbs clean everything replaces jets , pilots, seals , starts runs , ticks over fine pulls away just , went for a 50 mile run and it fly's along till i roll off the trottle and then roll it back on the revs die it splutters and struggling to get going till i get up to about 3000 rpm then it off ,,,i am sure the carbs are clean now ,, only seem to do it under load , ounces its moving its ok ?? anything more it could be ? run out of ideas now

So update gone back through the carbs clean everything replaces jets , pilots, seals , starts runs , ticks over fine pulls away just , went for a 50 mile run and it fly's along till i roll off the trottle and then roll it back on the revs die it splutters and struggling to get going till i get up to about 3000 rpm then it off ,,,i am sure the carbs are clean now ,, only seem to do it under load , ounces its moving its ok ?? anything more it could be ? run out of ideas now

Have you lifted out each diaphragm and slide and made sure that all the needles are ok ? Have you carefully inspected all the diaphragms for holes and rips ? What about the springs ? Are they properly seated and not kinked ? And finally have you cleared out any fine sludge that has accumulated around the slides ? I'm asking all these questions because this sounds to me like the time one of my carb needles snapped in two . The bike ran great once I got the revs up but ran like shit every time I slowed and then tried to speed up again . Not good when your 300 miles from home. I feel that if it is a fuel problem it might be in the tops of the carbs somewhere. Good luck . PS what about the little rubber caps that go on the nozzles that you use to balance the carbs , one of those hasn't fallen off has it ?