Please explain the numbering system on a spark plug (Champion N3C --- NGK BP6ES) and what effect a higher or lower number will have on a 1977 era Bonneville's valves, rings, seals (etc)? Will changing the plug heat range cease the pinging from low octane gas? Trying to remember 38 years ago, I think the bike came with Champion N3C plugs... All comments and suggestions would be appreciated.....
Try this link to NGK's numbering system. http://www.ngk.com.au/spark-plugs/product-information/part-numbering-system
I just referenced my spark plugs with the above link, many thanks for linking. Changed my plugs this morning and the Haynes manual says 'NGK CR9EK' for my 2010 Speedie which I bought, the Triumph service guys had put in 'NGK CR8EK' (about 10k miles ago) which are a grade hotter then the new ones I have installed according to the NGK numbering system. The specifications changed after VIN 461332, and mine is pre-change The plugs I took out where all lighted tanned on the white electrode area. Is this likely to have a negative effect on my bike...should I regress back to the 9's? Or where Triumph wrong and installed incorrect spec plugs at the full service last year?
the NGK site appears to say the 8s are correct if i have got your bike right. go to NGK and look. For what it is worth and it was close to 40 years ago(JEEZ), I used two grades up on my old 78 Bonnie and she fired so sweet in the cold weather but come spring I always changed back
Thanks and good call Sprintdave, I didn't realise the linked NGK website had a part lookup function However, the linked site is for Australia, and they say the 9's are correct for the speed triple Se 2010, which mine is (very specific). I then looked at the UK site, and they have a different filter function which encompasses all Speed Triples after 1991 and they suggest the 8's! Maybe it is a climate thing, with ambient temperature being an large enough factor alone to require the difference. I am happy to run it with the 9's in, next time I remove the tank and air box I will take 5 mins to check the condition of the plugs too.
Not a lot of people know this. But until I retired 6 years ago I worked for NGK for over 20 years. I am happy to help anyone with spark plug issues. However the first rule is always go with what the manual says. With NGK the higher number means a colder running plug.ie if you have tuned the engine you may need to go to a higher number- colder plug for a hotter engine. Looking forward to boring you all with my spark plug stories a the great meet. La Roca
