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Carb sense check please
aka Keith - 21/6/15 at 08:48 AM

the Head gasket went on my zx9r, so having replaced the head etc yesterday it will not fire up on 4th cylinder.

It will start but only run on 1,2 and 3.
Moving coils around does not change anything so not coil related
Checked compression all ok
Checked spark all ok

If I spray easy start into the 4th carb on lumpy idle it smooths out the idle and it sound briefly to be running on 4

So before I strip down the carbs I just wanted the collectives thoughts on it has to be the carb on the 4th cylinder yes?
I have not miss diagnosed or missed anything have I?

Cheers
Craig


CosKev3 - 21/6/15 at 09:09 AM

I would think so.
have you tried tapping float bowl incase its stuck before stripping?


aka Keith - 21/6/15 at 09:16 AM

I'll give that a go.
Cheers
Craig

SO I have given it a tap with a rubber mallet a couple of times. no change .

[Edited on 21/6/15 by aka Keith]


CosKev3 - 21/6/15 at 09:59 AM

Have you got a float bowl drain point on zx9 carbs? If so unscrew that and check if you have fuel in the bowl I would before stripping.


aka Keith - 21/6/15 at 10:06 AM

There was fuel in the bowl. started the strip down and clean. but so far cannot see anything really dirty or clogged.
hey hoh
Cheers
Craig


40inches - 21/6/15 at 10:31 AM

You may not see anything, but it will probably be there.
I had one carb that was blocked in the drilling's in the carb body. Flush the jets and drilling's both ways with carb cleaner
I use THIS


aka Keith - 21/6/15 at 10:57 AM

Well I have stripped main, idle , float etc soaked in carb cleaner and given them a good clean. stuck it all back together and nothing different. arrgggghhhh


cliftyhanger - 21/6/15 at 12:09 PM

Have you swapped plugs around? a rich mixture can right a few wrongs.....
Assuming it is COP, but if not HT leads too.


aka Keith - 21/6/15 at 01:02 PM

Swapped plugs and COPs no change. I expect that it is a carb issue and have stripped the idle jet and screw and will leave them soaking in carb cleaner for another hour or two


40inches - 21/6/15 at 05:42 PM

Been there done that Took me four attempts before I twigged it was blocked in the drilled connecting gallery, although I could ,sort of, get it to fire up by unscrewing the needle 6 turns. I fired the Wynn's Pro Cleaner into the needle hole and back from the pilot jet, with the jet removed. The Wynn's cleaner is under a very high pressure, for a can
Just a thought, the tiny "O" ring is still on the pilot needle?

[Edited on 21-6-15 by 40inches]


aka Keith - 22/6/15 at 04:28 AM

quote:
Originally posted by 40inches
Been there done that Took me four attempts before I twigged it was blocked in the drilled connecting gallery, although I could ,sort of, get it to fire up by unscrewing the needle 6 turns. I fired the Wynn's Pro Cleaner into the needle hole and back from the pilot jet, with the jet removed. The Wynn's cleaner is under a very high pressure, for a can
Just a thought, the tiny "O" ring is still on the pilot needle?

[Edited on 21-6-15 by 40inches]


yip 40inches, have sprayed jets of carb cleaner through the pilot jet holes so much that it came out the other side as you did. the "o"ring is still on the pilot needle. I break it down again and rebuild it again and see if there is anything I missed the third time around.


40inches - 22/6/15 at 07:47 AM

quote:
Originally posted by aka Keith
quote:
Originally posted by 40inches
Been there done that Took me four attempts before I twigged it was blocked in the drilled connecting gallery, although I could ,sort of, get it to fire up by unscrewing the needle 6 turns. I fired the Wynn's Pro Cleaner into the needle hole and back from the pilot jet, with the jet removed. The Wynn's cleaner is under a very high pressure, for a can
Just a thought, the tiny "O" ring is still on the pilot needle?

[Edited on 21-6-15 by 40inches]


yip 40inches, have sprayed jets of carb cleaner through the pilot jet holes so much that it came out the other side as you did. the "o"ring is still on the pilot needle. I break it down again and rebuild it again and see if there is anything I missed the third time around.


A lot of the bike forums are of the opinion that the only way to be sure is to get the carbs cleaned Ultrasonically, easier said than done