www.zxrworld.co.uk

Hi,

I recently had a problem with my ZXR 400 fouling plugs because it was running too rich. The bike is running fine now
but I have had to turn the mixture screw out one turn, any more than that and she bogs down badly from running too rich.

At 4000 revs roughly a quarter throttle just as she goes on to the needle jet she bogs down from being too rich and you then
need to open the throttle a little bit more to lean the mixture and the bike pulls away. When I first got the bike I set the
needle jet circlip to the third setting from the top as it was on the 1st and leanest setting when I bought the bike. I am
thinking perhaps she is now slightly too rich when coming off the pilot jet and onto the main jet. Can anyone tell me what
clip position they are running on their jet needles together with main jet size please. My main jets are 98 and my pilot jet is 35.

Finally I am also having a problem with the rev counter which is not all over the place. Not being too handy with electrics but if you have any
suggestions I would be glad to hear of them.

Regards

Have a look in the manuals for needle settings and pilot sizes, cant go wrong with standard settings id would have thought!

http://www.zxrworld.co.uk/zxr400/manual.html

As for the rev counter needle, if its all over the place (which i assume is what you meant) then that usually means a knackered battery in our experience. Another member here tried a new battery which didnt solve he problem, but a whack with a hammer did

I have changed the battery its Varta and made no difference.

As for the standard needle jet setting what is it? the manual just says #6 what the hell does that mean?

stock needles arent adjustable ..

sounds like you have some aftermarket (dynojet?) needles .. which is probably the cause of your "running rich" issues as they are designed to work with a KnN (or pipercross) filter and a race exhaust. #98 mains and #35 pilots are stock.. if everything else is stock, get some stock needles too as the profile is different so it doesnt matter where you set your adjustable ones, they will never be right everywhere.