Honda-SOHC

My understanding of spark plug technology  is they are designed to be  self cleaning at higher revs/temperatures - obviously there is a limit to this function so if the mixture is overly rich right through the range they will soot up.

I suspect throttle blipping was something we used to do to keep the plugs from sooting up at idle to make a clean getaway.

My experience primarily with cars using carbs is that a vehicle used for mostly short journey work fitted with the manufacturers standard plugs would foul up badly needing a good run to clear the carbon deposits.

I particularly remember a disabled customer who ran an Automatic Opel Commodore 2.5 GS (1974) from his home to work a  distance of less than a mile. On collecting his Opel from Ashbourne it would not exceeed 45-50 mph flat out. During the course of the journey to our service department  in Burton the top speed would slowly improve until it would reach 60-65 mph. After a service the car would drive like it should for a 2.5 litre straight six.

Fitting a different plug type to cope with the short journey used mostly on auto choke was not an option as the customer would drive to Scotland a few times a year where he had family. In reality he wouid have been better driving a car with a much smaller engine.

I fitted this one 15420-300-020P a Honda part iirc 17 mm head listed for the CBX1000 that fits the 500/550 etc

I think it differs from the original as it has a bigger bolt head - not sure if its Chromed or something like BZP.
Some of the cheaper aftermarket ones do not have as many holes in the center section.

https://www.ebay.co.uk/itm/264943691840?itmmeta=01HWDDES73CKH5R32S12N9A5G9&hash=item3dafdfe840:g:u6QAAOSw8NtftZ1Z&itmprp=enc%3AAQAJAAAA8AzdMM%2BMWvZhhc3hpVrufY7HefzhlpBjKh9LzaHr%2BTT80HHYlIkG7YpopkBeJ%2FZ3XZh9zXeBaFEunnCDsd59kDVcH5j8xDbcFsICz9d5BtbEkzKUc2pnCo2OAF31Uob6BMrjg%2FrdKilBzxfgSWoyHWTZlQgnb0uBUEumpEYCd4%2FUT2PcHd4F%2FsGJlq6YMUyP9j3BJOUwkNMNTzoicdxObtnFl8FEShqtm0GMg1uF7hszwt80PGodPrm7IqxcdLonbebs--hlBAFjJNdpl8%2Fmn%2BQ1SU60yojghbXjfGLWmDOVzJ%2F1B52BKx6eaDVoCu32NA%3D%3D%7Ctkp%3ABFBM0pO7reNj

.https://www.ebay.co.uk/itm/264943686943?itmmeta=01HWDDES73YBCGWN4KZ8V7S89P&hash=item3dafdfd51f:g:u6QAAOSw8NtftZ1Z&itmprp=enc%3AAQAJAAAA8JrIwGRHmeU0aMJnday6MO%2B1H1pfpTS9yb76oegYbFuMXrq1Fl1eV3Tws9HdYd0FJbf7oUns3U14PrOi9z8Z3jatktB%2FXDiCvT%2FGOQFh2tzFT0YzXPxeBXbB20dSWVnUR%2FKnBFuZmiEtRZDfz%2FhR1QrFK6xQEg%2BM%2B1ueBOuFFm13NQ7hJ7JGLbhUuqQ2YU56hDA%2B%2Fxbqg4fIaeMTStWhhAmofAcfB86Lql5Kfyd0QAswCjkxo%2FBYXbBGAZWytMZAyU3khw5oOJAkxKLHXa4pZzVpInUxBW4Qvqikwqlf4TZEQlLpcsqu82Fgtl2rL1GVMg%3D%3D%7Ctkp%3ABk9SR9KTu63jYw

I've noticed quite a few Websites where phone numbers, actual postal address are missing as well as a lack of e-mail address.
Some that have them keep them well hidden it seems with lots of navigation needed.

Digital Speedos website is a bit crap, there's no phone number but they do have a messaging service. I've gone backwards and forwards trying to get them to answer my question about speedo cables for a cb550 but not getting a direct answer.  I'm not sure how you can operate a business with no phone number.

Yeah, bunged it up with a rubber grommet, I’ve plenty if you want one

I’ll have a look later on for you, just out wobbling around the mendips today with ‘The Long Haired General’ on the back.

(I’m on my best behaviour)


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