how to fix carb stumble on 2000+ 9r's?

[Broism]

Originally Posted by David

So did anyone have any luck using the 0.5 mm washers?

WOW, it actually worked! Shimmed up .05mm and turned the adjusters 2 full turns and what a difference. It actually runs smooth at low rpm, haven't opened it up yet but will get back to you....WOOHHOO!

BTW one of the mixture screws was out by like 3 turns, so i highly recommend everyone should check there own out. It was super easy but i wish i had of run the system dry first, fuel everywhere!

Update: acceleration is scary better, i cant believe the difference .05mm shim and 2 full turns of the mixture screws. World of difference and it only cost $4 compared to the jet kit above and beyond $150

[Matts01zx9r]

i went and did the shim mod and adjust the screws out 2 turns now i still have an irratic idle, that pretty much lead to unsynched carbs?? oh and its a pain to get it started even when warmed up

[e1_ZX-9r]

Jet needle shimming should affect mid-range primarily and eliminate surging. What you're describing sounds more like a float height and carb synchronization issue, if not flooding from leaving the bike parked with the fuel tap ON. Look back in this thread to the bottom of the second page, there are links with instructions for each. There's also historic information, linked below, that might help you with your E2.

[Matts01zx9r]

thanks man ya im going to buy a carb tuning tool and see what it does.

[Matts01zx9r]

dumb question here on my 01 i found 2 vacuum connections one on the 1st cylinder and one on the last cylinder and i think theres on where the coolant line goes in. Arnt i suppose to have 4?? anyone have a pic i dont have a manual on hand

[e1_ZX-9r]

Maybe this link will help. Dunno exactly which tubes you're referring to, ones above or below or what. I'm too lazy to go out to the garage and check mine.

Pictures courtesy of Calamari Chris' Web site. Valve Adjustment for 2002 ZX-9r (Calamari Chris).

[Matts01zx9r]

the vacuum connection i have to use to synch my carbs i could only find 2 under the boot that is between the carb and engine block. The number 2 and 3 cylinders im lost on

[e1_ZX-9r]

Pictures courtesy of Calamari Chris' Web site. There are at least four photos at different angles on his nine page valve adjustment procedure (linked below...there are other pages). I just had mine all apart hours ago and it looks identical to the picture above; four intake vacuum hoses just under each intake boot.

[Matts01zx9r]

mine definetly does not have 4 2 and 3 cylinder are closed up and 1 and 4 have vacuum hoses routing to the right and up towards the spark plug area. and am i correct in saying there should be 4 adjustment screws?? i only see three. Sorry for all the questions its just none of this makes sense when im looking at my bike. Should be 4 adjustment screw and 4 vacuum lines each for a cylinder so it cant be adjusted and mine has 3 adjustment screws and only 2 ports where there is vacuum line coming out of it. I think the previous owner messed with it or something

[e1_ZX-9r]

Yeah, the previous owner probably tied the two cylinder head tubes together and removed the KLEEN air system. Shouldn't matter though, you can still do your vacuum synch using the holes that are plugged.

[Matts01zx9r]

oh ok now what about the whole having only 3 adjustment screws?? Shouldnt there be 4?? Dont get me wrong im pretty mechanical with stuff but this is kinda stumping me lol

[e1_ZX-9r]

Sorry everyone if this is a repeat of a repeat. Just wanna help this guy out. The ZX-9r carb synchronization procedure is in my post at the bottom of this thread's second page. Three screws is correct. Read my post, it will make sense.

[Matts01zx9r]

ok one more quick question in stock form are the needles shimmed up at all?? I found a smallllllll washer in each one of the carbs that was thinner than the .5mm one i was going to put in.

[e1_ZX-9r]

Originally Posted by e1_ZX-9r

...is in my post at the bottom of this thread's second page...

I think you'll find the answer there, see step #3.