Kawasaki ZX6R J1 starting problems

[Deranged Granny]

Hi all

I have a 2001 ZX6R (carb'd) which I've always had trouble starting from cold. It gets worse the lower the ambient temperature. The only way I can get it to start is with persistent use of the starter (~3 seconds on, 10 seconds off) for literally five minutes. It slowly but surely starts to hold idle for longer and longer until it holds. I'm surprised I haven't burnt out the motor yet. Turning on the choke kills it dead. This, along with the prodigious amount of pops and bangs on the overrun, suggests it's running way too rich. I've not had the chance to check the plugs yet. I don't think it's carb icing as it's only been around 5-10c when I've tried starting it. Heating the carbs / block / intake with a hairdryer seems to help? Starts on the button when warm.

I've checked my Haynes manual and it says to check the valve clearances before fiddling with the pilot screws. Is this necessary? It's only done 16k so I doubt the valves are out.

Shall I turn in the pilot screws a bit? Any other ideas?

All suggestions welcome. I want to stop starting my bike with a hairdryer.

[Lee540]

How do you start the bike?

If it were me, having many bikes with a choke.. just choke on full, clutch in and press the starter button without touching the throttle at all.

I would have also suggested checking the valves and changing the plugs..

Edited by Lee540 on Wednesday 21st March 10:14

[orangefzr]

I would be checking the airbox for obstructions like a mouse / rat nest, and removing carbs, cleaning any ste out of the jets and checking the positions of the pilot screws to start with, as you it does sound rich, but could still be something like a blocked choke jet as well
When did it last have spark plugs?

[Biker's Nemesis]

Spark plugs.

[xeny]

A friend had these symptoms on a Triumph - it turned out to be too tight inlet valve clearances :-(

You've presumably tried dumping a bottle of https://www.toolstation.com/shop/Automotive/d60/Mo...

(yes, I know it says injector, but it seems to work fine on carbs) through it?

[Cbull]

Had similar with my CBF125, it was the valves.

You say "Turning on the choke kills it dead.", surely it's meant to be on when trying to turn it over but obviously not whilst riding? When cold and my choke ain't on the bike doesn't even entertain starting up.

[Deranged Granny]

Thank you for the responses. Spark is the most sensible explanation. I bought the bike late last year but have only ridden it a handful of times and it is probably due a service. I should perhaps have considered that...

I don't start it with the choke as it will simply not fire with it on; it seems to be rich enough already.

If plugs don't cure it, I will check the clearances but am reasonably confident that shouldn't be necessary. Fingers crossed.

[graham22]

Valves could be an issue, had the same on a FZR1000 where they tightened up, were held open when cold & would not start due to slightly low compression.

Worth checking these first as won't require any parts.

As running rich, I understand Kawasakis of this era suffer from wear of the carb needles & emulsion tubes, even more so if a Dynojet kit has been fitted, no adjustments of idle/mixture screws will cure this (it may help but will mask the problem). Can you borrow a set of 2nd hand carbs?

[orangefzr]

It wouldn't hurt to check the valve clearance BUT the op says the bike runs fine when hot..... If the clearances were tight to the point of the bike not starting it would backfire through the exhaust system when trying to start it, and when the engine is hot the clearances would be even tighter, a bottle of fuel injector cleaner could be a good idea if you don't fancy taking the carbs off. Checking they're balanced would also be a good idea

Edited by orangefzr on Wednesday 21st March 13:21

[xeny]

My experience of the bike in question was it started fine when hot.

I'd guess the aluminium of the head expanded more than the steel of the valves once they were all warm so effectively the camshaft ended up further away from the valve seat by more than the valve got longer, but it's only a guess.

[orangefzr]

I just checked google on your behalf and apparently this particular bike needs the valves checked/adjusted every 7500 miles, so unfortunately for you it looks like you do need to get the valve cover off if it's now sat at 16000, sorry to be the bearer of bad news, I can't believe it is such a low amount of miles for a valve service, my yam is every 28000 miles

Edited by orangefzr on Wednesday 21st March 13:23

Edited by orangefzr on Wednesday 21st March 13:35

[Cbull]

I've done about 14k miles on mine since I bought it last year. Think mine may need doing too

[Deranged Granny]

Thanks again. I'll change the plugs and report back. I think I'll do the valves soon as well now, in any event!

[WhiteBaron]

my friend has the same bike, in the winter with an aftermarket exhaust fitted it was a pig to start, put the standard can on and it was fine. We put it down to back pressure or lack of.



in the end he has stopped swapping and left the standard can on - but I think thats just because we are getting old!

[Rubin215]

Biker's Nemesis said:

Spark plugs.

This.

90% of carb issues are spark plugs...

[abw280]

It could well be water gathering at the bottom of the tank, try draining the tank completely and only use super unleaded if the bike is only getting used infrequently.

[moanthebairns]

I've a similar problem with my G. I've had carbs, done, clearances, plugs, leads, checked hoses, flung cleaner in. I do need to sync carbs.

If you figure it out let me know. If not I'm taking it to someone who knows what the fk they are doing

[pozi]

From experience with mine and a friends G2 & J1 the valves clearances will definitely need adjusting by 15K miles, they seem to settle down from then on wards though.

It does not sound like the exact cause of your problems but I would be confident that the valves won't be helping it.

[Deranged Granny]

Big, big thanks to everyone for their help, and especially to those who said spark plugs Replaced them and it started with no choke after an agonising five seconds of turning over (probably about right for an old bike in cold weather). I am velly, velly appy.

And as a bonus... it pulls MUCH harder all through the rev range. Wayhey.

For what its worth, the old plugs looked sooted as expected, but otherwise fine. However, worth noting that they were iridium plugs and I replaced them with standard ones. Perhaps that was a factor?

Time to enjoy the first gear power wheelies

[Cbull]

Excellent! New bike feel for you

I have a J2 model and went to Bill Smiths Motorcycles yesterday for a smooch around. They had a J2 model for sale, less than 10k miles and not a spec of rust on it. It looked brand spanking new and definitely hadn't seen a spec of rain in its life. Everything standard for £2.7k which is a little pricey for a 17 year old but seemed fair considering its condition. Made me feel like I had a right knackered rust bucket of a bike ha ha.

Found a link...
http://www.billsmithmotors.co.uk/pages/used/used-b...