Suspected carb issues - running very badly

[mxj560]

Hi all

I am having some issues with my L2. Prior to the new year my father and I had been running it warm, just to make sure everything was ok, and had noticed that when revving in neutral the revs would hang at around 2k and slowly settle back to idle. To be honest, we didn't think a whole lot about it.

About 3 weeks ago, we did the same, and this time it was running very poorly, very burbly. We assumed that it was due to their being very little fuel in the tank and the engine was running low.

Well, yesterday we went through the process of changing the oil, filters and plugs. However, prior to this I had put about 5 litres of fuel in the tank. Again the bike ran very poorly and burbled. Not only this, when revving the bike would struggle to rev out and would often cut out or drop back to idle if revved hard. It sounded and reacted very much like there was not enough fuel getting to the engine.

Having looked around on the forum, my father and I have come to the conclusion that there is an issue with:

1. Air leak in the carbs
2. Fuel pump issues.

My father has today taken the top end off the engine and has noticed that the rubber housing under the carbs (pictures below) has gone very hard, and on one of them there is evidence of blowing.

IMG00315-20120304-1813.jpg

IMG00316-20120304-1814(1).jpg

I have found the following kit on ebay and suspect it may be something to do with the gasket or the o-ring, but am really unsure:

http://www.ebay.co.uk/itm/KAWASAKI-ZXR4 ... 3f0fd5a9cc

Has anyone got any experience of this? If so, could you let me know if what we are looking at is correct, and if it is the part in the picture, the kind of price I am looking at to repair?

Any other thoughts or ideas greatly appreciated!

Many thanks

Matt

[cargo]

That linky is a repair kit for the carbs.

I'd guess Cradley will have new sealing rings for the carb rubbers................but I've always just used some sealer,instant gasket.

I also suspect that carb rubbers are one of those rare items that are no longer available new ?...........

[thomp1983]

cradleys can still get the car rubbers but there about £20 each or something silly like that

chris

[mxj560]

Crikey, at that price I am better buying a good used set of carbs on flea-bay!

Cargo - I have looked at the workshop manual and can see where the gasket in that link sits. Is there a chance it could be that gasket that has gone, thus causing an air leak? If not, any other thoughts? I can post a video of the noise the bike is making if that helps at all?

Ta for the help thus far!

[thomp1983]

easiest way is to remove the tank and with the bike running gently spraying carb cleaner around the carb rubbers, if the revs suddenly rise you've found your leak

chris