Z1OwnersClub GB

My z1000 1979 which has a mk11 engine is again starting from cold on 3 cylinders. Had same problem in Spring. I put new plugs in and all was well. Only covered about 300 miles and it's at it again. Starts fine with choke, then runs on 3 with some back firing and odd shot of flame. Given 3 minutes or so number 4 kicks in and runs beautifully. Took it a 50 mile run then left for a couple of days. Same thing happens all over. Plugs are bog standard ngk b7es. Not had chance to pull plugs yet but last time one was not sparking. Advice welcome please on changing plug spec or other thoughts? Thanks, Ian.

First off swap lead & plug with other one on same coil..... ie: 1 - 4 or 2 - 3..... any changes?
Then get some Denso plugs..... NGK can be dodgy, even new plugs can be naff.
Newer plugs seem to give up the ghost soon as they "wet" and never recover fully!?

Ebay ngks are often fakes and real shite. Even genuine ngks need at least one grade hotter with modern fuels.
Get denso's you know it makes sense.

Thanks for replies. I swapped leads and plugs last time, was the plugs. Will do same again asap. Will follow advice here and get some Denso plugs.w22es u yes?

I use IW24... the Iridium plugs - a bit pricey but always done me well over several bikes in the last +10yrs

Thanks again il give them a whirl.

Fuel can go off in a few weeks , if it wets a plug then usually the plug is shot . Any bike we get with fuel issues we use Shell v power in them as it has the least ethanol.

Where do people get Nippon Denso plugs from

I've found SparkPlugs.co.uk and the ordinary ones are £2 each and the iridium ones £8 each, which seems suspiciously cheap to me.

I buy mine from here - http://www.ebay.co.uk/itm/IW27-DENSO-IR ... 2749.l2649
They are the cheapest I can find at just under £7 each.
The ones in the listing are NGK9 equivalent which I favour in non stock motors.
They do hotter grades for the same price.

Julian_Boolean wrote:I've found SparkPlugs.co.uk and the ordinary ones are £2 each and the iridium ones £8 each, which seems suspiciously cheap to me.

I get mine from them and have not had any issues.

warren3200gt wrote:

Julian_Boolean wrote:I've found SparkPlugs.co.uk and the ordinary ones are £2 each and the iridium ones £8 each, which seems suspiciously cheap to me.

I get mine from them and have not had any issues.

Yes I have bought from them, very good, had a similar problem on my z250, had a chat with the man from Spark plugs, very helpful sorted out my problem.

Try gently pulling the plug cap of the offending plug slightly while its ticking over. You should hear it start to fire when there's a gap between the cap and the plug. Let it run for 30sec or so while it warms up and cleans itself. You won't get a shock as long as your leads and caps are good but if you're not brave use some pliers.

Fitted IW24 plugs this morning. Fired up on all 4 and settled nicely on tickover. Took for spin and all is good. Thanks for the help. Fingers crossed these plugs will last longer than the NGK ones did.

Ian.

If there is a specific underlying problem, it'll raise it's head again, but them Denso's is the business

Thanks Mr Pigford...now il be worrying lol. Actually I have been wondering what might cause this problem other than crap plugs. The twice that its happened it has been number one first time and number two plug the second time that gave up the ghost. They look fine but just don't spark. Have to wait and see.

Ian.