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Help With Fcr Jetting...(Please)


Toneale

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Hello Boys and girls.

I am in the process of putting 39mm flatslides on my 92 fireblade and need some help with the jetting/settings.

The carbs came off a ZX9/ZZR1100 so its likely the jetting is probably off by considerable amount. I am looking for a base setting for the jets which can then be tweeked on the dyno.

The carbs are currently running the following jets/settings:

Needles OCEMV (Taper 1º00', L1 79.15mm, Root d1 2.795mm) centre clip position.
Main Jets #150
Pilot Jets #52
Float Valve 2.0mm
Slow Air Screws Fitted (Adjustable, instead of jets).
Main Air Jets were not fitted as the kawasaki airbox adaptors originally fitted had a take off arrangement so any advice on sizes gratefully accepted.

The engine is in a mild state of tune (gasflowed and skimmed head, Kent half race cams, pipe etc). I will be running bellmouths if that helps.

All info gratefully received.

Ta muchly :thumbsup:

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A 92 fireblade will be running

Main #120

Pilot jets #40

Needle 0.25=J5FS & 0.75=J5FR

Base this on what you have....

Needles OCEMV (Taper 1º00', L1 79.15mm, Root d1 2.795mm) centre clip position.
Main Jets #150
Pilot Jets #52

IMVHO you could do loads of guessing but until you get it on a dyno its all guesswork and probably a waste of money.What i mean is you could shell out an getting a few jets only to find they are all wrong once you got on the dyno. You are far better (IMO) to let the dyno people sort it out one the 1st go as it will save you time and hassle.

or you could try.. :biggrinvk4:

#140 main

#45 pilot

The needle clips will allow some adjustment

This is about in the middle for cc/min.But again its a pure guess from my crystal ball borrowed from septic peg...get a dyno booked and get it done right the 1st time.. :icon_salut:

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If you were to even just get the mains right from doing some bodgey maths it'd be a hell of a shot in the dark, yet alone the pilots, the needles and the float heights. Stick it on a dyno and even with only an hour or so of faffing about you'll have the mains right and the needles somewhere close. You'll also find that Mr Dynoman has a selection of jets ready to go in, save you spending a whole load on jets that don't quite fuel right and then having them just sat there.

Then you could also take into account that badly set up FCRs will probably be worse than CV carbs on factory settings, but in saying that, I realise you'd probably just get it on a dyno at some point to do the fine tuning and you're only after a ball-park to get it running. In my opinion, just bite the bullet early on and get it dyno'd right first time.

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Some sage words people. cheers. :thumbsup:

I think I'll leave it to the dyno guy to do the necessary and take the guesswork out of it all.

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Have you got a dyno run before FCRs , it always interesting to know how they compare to CVs

Sorry I can't help with jetting I'm in the same boat as you , ive left it with the experts but my bike has been on the dyno today with the FCRs and theres still work to do

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Here's the current dyno chart. managed to get peak output up to 138 bhp but eventually settled on 131bhp (bottom chart) as it had a slightly better torque curve.

I hoping to get another 3-5 bhp across the range with the flatsides.

Dyno2_zps187c9565.jpg

dyno_zps4eda1e81.jpg

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170 mains, 200 main air jets, EMP needles, 52 pilots and work from there on the dyno. I wouldn't be astonished if you got more than 5-6hp.

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132bhp from a 92 blade?? What has been done to it?

1.5kg off the crank lightened and balanced to the stock rods;

Stock pistons

Kent half race cams

Polished and ported

Head skimmed to bring compression up to just under 12:1

Stock valves

Stock Carbs and airbox with K&N filter

Ackrapovic race system

Dyna 2000 ignition

Dyna Coil

Solid core HT leads

plus a few other odds and ends...http://pbmagforum.co.uk/index.php?/topic/38056-21st-century-fireblade/

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