Yamaha Ninja Please save me from insanity

[andrew-capp]

My XJ600 starts to stutter and stumble at 6000 rpm and some advice would be gratefully appreicated.
I have been told many times that a litre of petrol and a Zippo will cure all my worries but I'm kind of fond of the old girl.
The beast runs ok until 6000 rpm and then sounds like it?s choking and it stutters but if you keep the throttle on it slowly clears.
This is constant and the Carbs have been balanced but reading another good thread on the fuel air mixture how many turns out from seated do I have to turn and is it the same for all 4 carbs.
Somebody said it might be a torn diaphragm and I will look into this if anybody could confirm this.
Thanks in advance for any help or words of condolences chaps and thanks for the site.

[ArrrGeee]

Hi,
this is primarily a vision forum (XZ550's) but we won't
discriminate seeing as it's a Yamaha.

Yes, it could be a torn diaphram, or a plugged carb or
a large air leak. checking the diaphram's is pretty simple,
just pop the cv covers off your carbs one by one and have a
look. While your there, make sure that all the slide needles
are clipped on the same notch. also make sure the slides
move up and down smoothly in their bores.

you'll want to check your inline fuel filter to make sure it isn't plugged and the pickup in the tank as well.
If you you don't have an inline fuel filter, Get one !

lastly, if all of that is ok, you'll want to pop the carb bowls off
and see if they have any gunk floating around in them....

good luck.

-Ron

[andrew-capp]

Thanks Ron
I'll meet you in heaven for a pint or six.