California eating spark plugs

I have an 86 California 2 which is stock apart from K&N filters, The bike has an appetite for spark plugs which is baffling me slightly.Plugs only last approximately 450 miles, until then the bike starts and runs beautifully, after 450 miles it will start misfiring from a closed throttle and will get worse until new plugs are fitted.It has stock jets and the mixture looks fine, points and ignition timing are spot onPlugs are BP6ESAny ideas?

possible that they are fake plugs

Could it possibly be an ignition fault, like failing HT coils, which can spark a new plug but start to struggle as soon as the plug surface fouls even slightly?

The hand book for the California EV states that the plugs should be BPR6ES those are the resistive plugs rather than the standard BP6ES don’t know if that makes a difference but worth trying.
Regards Keith

Oh yeah THAT is why the plugs are failing …wrong plugs buddy

Hmmm, I have had strange things happen with NGK’s before, hence I keep going back to Bosch. From my ‘Bosch to NGK spark plug cross reference’ list (from orft webernet): Bosch vs NGK numbers: W5D BP7ES }W5D1 BP7ES } 850 Le Mans 1/2/3 ***W5DC BP7ES }W5DCO BP7ES }W5DCX BP7ES-11 W5DP BP7ES } W6D BP6ES }W6D1 BP6ES } 850 T3/4/5 Cali Spada Convert G5 etc.W6DC BP6ES }W6DCO BP6ES }W6DCX BP6ES-11 W6DP BP6ES }W6DPX BP6ES-11 W7DC BP6ES } BMW R80 Latter just added FYI but note W7DC is ‘hotter’ than W6DC which is what BP6ES equates to. So BP6ES would be ‘too cold’ for the R80 unless thrashing it a bit or hot weather. Maybe. Whether or not the plug has a built-in resistor shouldn’t matter and many caps have them anyway (such as the red/black NGK booted waterproof ones which I do like, even if I haven’t had much luck with their plugs).

Assuming that you have not fitted electronic, have you changed the condensors?

This is useful
Sadly the Cali II is not listed.
I’ll have a look in my old catalogue.
Best of luck

When you say its wrecking the plugs – when they start to fail in the 500 miles are they showing any signs of excessive wear on the electrodes could it be running very lean causing pinking etc that is actually exploding the electrodes away ?

Could you attach a photo of a wrecked plug?
All the best,

Thanks for all the help and advice everyone! plugs come out looking as you would expect from the mileage, like new with no sign of wear at all. They just don’t work properly.

The NGK catalogues I have don’t list the Cali II. They do list most models before (Tontis) and after Cali III etc.
There is a listing for 950 series which may well be your bike this specifies the plug you have.
Could the plugs be a symptom rather than a faulty component?
Good luck

If they are looking like they should after a low mileage, surely the fault lies elsewhere. Have you checked the spark after you’ve taken them out? And how about a quick clean with a light wire brush?

Yes I was going to say, he didn't say "wrecking plugs" he said plugs only last approximately 450 miles.   Again I suggest try a different brand, if only for elimination purposes.    Otherwise you might end up with the bike in bits and you tearing your hair out looking for a non-existant problem.  The very rare occcasions (2 I think) I tried NGK's they were chucked in disgust well before 450 m. They certainly didn't appear to like the Rita ignition system, put the old Bosch's back in, no problem-o. Chalk and cheese.

I will try some Bosch plugs and see how they lastThanks again for the helpChris

Hold on a minute, folks! The key issue is…K&N’s fitted…and still got STANDARD jets.That will run lean…hotter…and eat plugs. Go up 10% on the stock main-jet. AND go up +2 on the needle jet sizing. That should fix the appetite for plugs.

well done Timmy

“stock jets” well spotted. It’s a V1000, so I’m guessing stock is 125 (?), so probs needs go up to 135 - 140 -ish Which carbs VHB or PHF ?

I need to get out more, I looked at thread title and thought it was something similar to 'The day of the Triffids’rbt15482013-10-12 13:25:34