Forum

[Michael]

Today's update...



The whitened plug is out (NGK no6). I need transport so put back the old plug (BOSCH no 6) which kept fouling up (posted on this a few months back). Well... very little evidence of noise this morning, and a lot less hot. Only two things have changed: the weather is MUCH colder today and another plug is in...




Could my worries be down to a dud plug?




Also, the engine is probably due for its first decarbonising according to my service manual (I have done 16500 miles now)... might this also be a factor in my woes? And would a novice along with a decent brain (apparently), a service manual and the keen-ness be able to carry out such a job? What pitfalls exists which are not documented?




I will get it off for an electrical 'once over' after pay day... we'll see.

[grunda 12]

hi michael i wouldn,t bother de coking your bike at 16000 miles the efi engine doesnt burn too much oil as it has valve stem seals the bike ive just fitted the new crank big end in had very little carbon on the piston crown (yours could be different but i doubt it )and the plug will be that colour due to being probably a very weakend injection mixture for immissions ive not seen a nice coloured plug on an efi yet ,if your having plug problems that would not be unusual they don,t make them to last anymore unless your lucky as theres bound to be some wag who,s done 3 times around the globe on the same plug!!!atb paul efi surgeon but thats another story!!

[Michael]

Hi Paul, cheers for the tips. Chief EFI surgeon I suspect!! I'm more worried about the noise than the plug. But am led to believe the colour of the plug could indicate a reason for the noise. Will find out in Thursday - bikes going for a check up. m

[grunda 12]

hi michael i hope things are ok with your efi i cannot say that i,m totally impressed with what i have seen in the depths of the efi some things look like after thought bodge ups and then some of it looks quality i wish i could put photos on here i,d show you the crank pin from this efi ive just built i think i may make it into a trophy for juan who blew it up its terrible atb paul.

[Alan R]

Hi MICHAEL --------- just to add a little help at this point..have another look at that plug photo you posted... Notice the colour of the tabletop behind ??.. That's the sort of colour you need to aim for, the much-described " Light coffee" color (with or without sugar, it's up to you !!)............

[Frank]

The centre electrode is certainly white but the outside electrode show a hint of a tan so I don't think it's beyond tweaking. You have to be careful with plug numbering schemes as NGK number a different way to the rest, but they do seem to come together around 6 so a NGK 6 and Bosch 6 are in about the same heat range. If the noise is helped by a change of plug, and made worse by a change down to normal unleaded, then it does sound as if it's pinking, possibly caused by an overheating plug. I would try a colder plug an NGK BP7ES and see how it goes regarding colour and noise, at least until you get the fuelling checked. I take it the plug is a genuine NGK and not one of these fakes that are supposed to be knocking around?