Carb tuning

[510racer]

Hello,
I just fitted a set of new CR29's to my Z900.
They were bought set up for a 900 and after playing with idle jets it is starting well and revving out ok.
Only problem is when you give it a quick twist of throttle it wants to take off then it stumbles and has a HUGE hesitation.
Twisting the throttle progressively seems ok (without any tuning) but it's just when you give it a quick squirt it falls over...
I was thinking that maybe the floats are set incorrectly and there is not enough fuel in the bowl when you ask it to launch, but before i go adjusting the float heights I just wanted to check if I am on the right track???

Thanks.

[nw66]

I had a set of 29's on my 900 and had the same issue its running a bit weak where the hole is I adjusted the needle height to add more fuel and hey presto I got it running pretty much spot on. I did get it on a dyno though to get it as good as we could. Hope this helps

[Pigford]

Standard Zed carbs always tended to hesitate on initial pick-up which was partly down to old design.

As nw66 said above, raising needles may help a bit, but it could also need size up on pilots?. Are they "pumper carbs" - if so check the accelerator pump action is operating as per manual? CR's can be a b*****d to tune - thats why Mikuni's are a common choice

[nw66]

Standard Zed carbs always tended to hesitate on initial pick-up which was partly down to old design.

As nw66 said above, raising needles may help a bit, but it could also need size up on pilots?. Are they "pumper carbs" - if so check the accelerator pump action is operating as per manual? CR's can be a b*****d to tune - thats why Mikuni's are a common choice

Don't think the CR's have a pump?? the RS's do though!

[CAT3]

Not sure where you live in the country, but this guy would be well worth visiting or at least speaking to,

http://www.otcdynocentre.co.uk

Pete Alton is a very good guy & knows his stuff by all accounts.

[paulmceleney]

I had this problem with my bike smoothbore carbs I think your main jets are to big you could drop four sizes and start from there.Also check your plugs first to see what colour they are also you could open your air screw more to see if this makes any difference you only need to adjust a little bit at a time move 3mm then take it for a ride

[nw66]

[baz]

i always find this way the best at setting carbs up .........
remove the exhaust system from the head and start the engine
when warmed up set the tick over slightly higher than norm
turn the garage lights out and adj the mixture screws so that all
flames are the same length and a nice light blue colour.
Its like doing four colour tunes in one

[Pigford]

i always find this way the best at setting carbs up .........
remove the exhaust system from the head and start the engine
when warmed up set the tick over slightly higher than norm
turn the garage lights out and adj the mixture screws so that all
flames are the same length and a nice light blue colour.
Its like doing four colour tunes in one

No wonder you're half deaf (as well as daft)

[KeithZ1R]

i always find this way the best at setting carbs up .........
remove the exhaust system from the head and start the engine
when warmed up set the tick over slightly higher than norm
turn the garage lights out and adj the mixture screws so that all
flames are the same length and a nice light blue colour.
Its like doing four colour tunes in one

now that IS impressive

[baz]

i always find this way the best at setting carbs up .........
remove the exhaust system from the head and start the engine
when warmed up set the tick over slightly higher than norm
turn the garage lights out and adj the mixture screws so that all
flames are the same length and a nice light blue colour.
Its like doing four colour tunes in one

No wonder you're half deaf (as well as daft)

what did you say

[nw66]

[Z1parR]

i always find this way the best at setting carbs up .........
remove the exhaust system from the head and start the engine
when warmed up set the tick over slightly higher than norm
turn the garage lights out and adj the mixture screws so that all
flames are the same length and a nice light blue colour.
Its like doing four colour tunes in one

No wonder you're half deaf (as well as daft)

what did you say

I can see now why i was having to shout when i was last at yours .
I thought you couldn't hear me over the dogs .
It was that ringing in your lugs

[baz]

Go on, take the piss

Bet your all in the garage tomorrow though with the exhausts off and a tampon in each hear

[nw66]