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FZS 1000 longer cold start
#1
I need some advice.
Over the winter, I removed the carburetors. I blew out the jets, inspected and cleaned everything, and replaced all four float bowl gasket sets (CAB-Y39). I set the float height according to the service manual and adjusted the idle mixture screws to 2.5 turns out.
The motorcycle runs perfectly: it idles smoothly, throttle response is instant, the RPM drops back immediately after revving, and there are no hesitations, bogging, or flat spots at all.
BUT...
On the first cold start, the engine cranks for about 3–5 seconds. It initially sounds like it's about to catch, then spins freely for a couple of seconds, then catches again and starts. With the choke fully on, it settles at around 2800 RPM.
Also, if I ride the bike and then leave it parked for a couple of hours, it will still take 2–3 seconds to start, even with the choke applied.
Could someone please advise? Would it make sense to turn the idle mixture screws out to 3 turns, or is this more likely a float level issue that would require going back into the carburetors and adjusting the fuel level in the float bowls?
The bike runs absolutely flawlessly once started. My only concern is the starting behavior. Thanks in advance for any suggestions!

I haven't checked the fuel level using the drain-hose-into-a-bottle method. Before starting the bike, I usually wait about 5 seconds until I hear the fuel pump relay click.
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#2
Why did you remove the crabs over winter? Was the bike cold/hot starting fine before you removed them? If yes you need to check your work, clean, inspect/ check everything.
Later
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#3
(01-06-26, 10:11 AM)Gnasher Wrote: Why did you remove the crabs over winter?  Was the bike cold/hot starting fine before you removed them?  If yes you need to check your work, clean, inspect/ check everything.

I was having issues riding through the city. When cruising at a steady speed, the motorcycle would shake/jerk.
Before I touched the carburetors, it didn't start very well, whether the engine was cold or warm. Now it's become slightly worse for a second or two when starting.
As far as I remember, the mixture screws were set to 3 turns out, but I could be mistaken.

I'm not sure that adjusting the idle mixture screws to 3 turns out would actually solve the starting issue. I might try it out of curiosity, but the third cylinder is very difficult to reach, so it's not something I can easily test.

That's why I decided to ask for advice from more experienced users first.
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#4
You need to set them as per the manual, provided the bike is standard or as per Ivans if it's been modded. It's likely you've got crap in one or some of the pilot circuit air galleries/ jets still. These can be notoriously difficult to clean sometimes, many think they've cleaned them only to find out they haven't on reassembly.
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#5
Following on from Gnasher's advice, I would add if you can afford it send the carbs off to be ultrasonically cleaned also.
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#6
Word of caution regarding ultrasonic cleaning.  If done properly it will clean crabs up but it will not unblock air bleed/fuel passages beyond a certain point, only physically clearing will unblock them.  I'd also add there's a huge variation is quality offered by individuals/companies offering ultrasonic cleaning. 

I've worked on many sets of carbs that have been ultrasonically cleaned, when in reality they been dipped in hot soapy water at best.
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#7
I would look at adjusting the float levels to 15mm as per Ivans guidance. Its well documented that 13mm causes the carbs to flood especially if on the side stand.

Happy for you to come find me on FB, ive a very public page and have perfected my carb work.

Vapourblasting & Ultrasonic cleaning done together and not just dropped in hot soapy water lol

Lots of advice to give free of charge ?

Richard Mark
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#8
(Yesterday, 12:10 PM)RMT1983 Wrote: Vapourblasting & Ultrasonic cleaning done together 

its good that we have a member that can provide this service, do you have some links to jobs you have done or better still to members on here..?
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#9
Loads on my profile on FB - dont want to take over someone's post with my stuff though... maybe a thread for the links?
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