www.zxrworld.co.uk

Hi guys,

you lot ahve been so helpful in the past, I'm sure you'll know wot this one is...

Cold starting problems, hot starting problems, stalls at slow speeds/slow gear changes, erratic idling, stalls when I use the choke. Stutters at 10K rpm. Battery is okay and the temp gauge stays below half.

Bike set up is standard apart from pipercross filter, carbon race can and nutter sat on the saddle!

Says 14,500 miles on the clock, but it is an import with a UK clock, so how true that is is anyones guess!

I think the carbs need balancing, what do you guys think? Or could it be the valves?

thanks
Sean

i would certainly look at getting the carbs balanced, change your plugs, check HT leads and check the coils if you have access to a multimeter.

what sort of voltage should I get from the coils?

Are those twin spark plugs any good?

How much does balancing normally cost?

so many quastions, so little time...

If your prepared to do it yourself, then it will only cost you the price of a set of gauges which are about 30-40 quid, your time, and a free print out of my workshop guide:

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

The erratic idling sounds like the carbs need balancing, may even be some carb icing, but its worth checking the carbs and perhaps chuck in some redex to give a clean too.

Not sure how much the plugs are if you want to change them, may just need a clean and the gaps resetting. Bur dont go for irridium ones if you cange them, its not really worth it, just the standard plugs will be fine

I spoke to the guy at the garage where I bought it and told him I was having problems and the likely causes based on what I have read here. He said that as I have only had it a couple of months he would balance the carbs for free. I will ask him to clean/regap the plugs whilst he's in there.

It is good to find that not all garages are cowboys.

Thanks for all your help, it gave me the confidence to call the garage with a possible cause and that's what has saved me a few quid and some headscratching!

The bike is not due to go in til the new year, so I'll let you know the outcomes.

As it is so simple (following your helpful guide) I will get some gauges in the new year so I can check it myself periodically, should keep it sweet!

Thanks again guys.

sean

what kind of filter is it? like is it 4 cones or something?

also worth checking the mixture could be too lean? but that rearly goes out of sinc.

hope you get it sorted hassle free!

after fitting a panel filter and race can, it probably wants re-jetting.

It's a large oval cone filter with two butterfly nuts holding it in place. Looks pinkish when dry, reddy brown colour with the oil on it.

What does re-jetting involve, honing the needles?

thanks

Bike went back yesterday for carb balancing. He said it would only take an hour and he'd call me when it was ready, still no sign of it! I think maybe there is more to it than just a carb balance. I hope its ok. Gonna call them tomorrow. Fingers crossed!

Got the bike back today, still the same. It is like there is back pressure in the exhaust or something. I think it must be a sticking valve or the valve timing is out or something.
The mechanic was very surprised. It did sound sweet when I first started it, but when I was riding it kept stalling between gear changes and stalled at traffic lights, took ages to start up again.
Anyway I took it back and he's gonna have another look at it.
Bugger!