CB550K3 plugs

[Ashdowner]

I'd like to think that the previous owner of my bike had spent hours on research and testing to identify the optimum NGK plug for each individual cylinder and that he wasn't in fact some dickhead who threw in whatever was lying around in his workshop. Anyhow I've fitted the standard DR7ES and it will come as no surprise to any K3 owner to read that it has made no difference to the tickover and it still sounds like a dog giving birth. [ Guests cannot view attachments ] .

Can someone please explain the "clear-tube method of checking float levels on the P46 carbs and tell me where to fit the aforementioned clear tube?

[Woodside]

I'd like to think that the previous owner of my bike had spent hours on research and testing to identify the optimum NGK plug for each individual cylinder and that he wasn't in fact some dickhead who threw in whatever was lying around in his workshop. Anyhow I've fitted the standard DR7ES and it will come as no surprise to any K3 owner to read that it has made no difference to the tickover and it still sounds like a dog giving birth. (Attachment Link) .

Can someone please explain the "clear-tube method of checking float levels on the P46 carbs and tell me where to fit the aforementioned clear tube?

One of the most descriptive posts of the year.....

[Bryanj]

Shouldn't have resistor plugs whatever SOHC it is

[Johnwebley]

maybe he/she found the 2 center pots ran hot

[ka-ja]

Hi,
    Agree with bryanj, had this discussion with the D Silver bunch, after they sent me D8Es plugs for my 400/4, maybe OK for unsupressed metal caps, but my local Honda dealer recommended D8EA plugs for use with the more modern suppressed plastic caps, that was 1985, never had any spark trouble even in the wet with them, I think the above were a set of freebies from a breakers!

[Johnwebley]

Hi,
    Agree with bryanj, had this discussion with the D Silver bunch, after they sent me D8Es plugs for my 400/4, maybe OK for unsupressed metal caps, but my local Honda dealer recommended D8EA plugs for use with the more modern suppressed plastic caps, that was 1985, never had any spark trouble even in the wet with them, I think the above were a set of freebies from a breakers!

 thought the resister plugs had a suffix "R"

[Ashdowner]

Why is life so complicated. How do I tell if I have resistor caps?

[ka-ja]

Hi John, apologies, plugs sent by D Silver were DR8ES-L, anybody want a set of 4 cheap! NGK recommended plugs are not resistance type plugs
            Ashdowner---Apart from plug type/number, NGK also have "R" printed under the NGK logo. Float level with clear tube probably involves fitting a modified drain plug under the float chamber to fit a level tube on? maybe wrong,I've never needed to do it! ---Ken

[Ashdowner]

Final comment - I've checked and I have 5K Ohm NGK -plug caps on the bike. I found a previous thread on the subject that says you should use resistor plugs with NGK 5K caps i.e. DR7ES which is what I have, and it's probably why David Silver and Wemoto etc list them as the standard plug for the K3.

[Johnwebley]

Final comment - I've checked and I have 5K Ohm NGK -plug caps on the bike. I found a previous thread on the subject that says you should use resistor plugs with NGK 5K caps i.e. DR7ES which is what I have, and it's probably why David Silver and Wemoto etc list them as the standard plug for the K3.

   I believe if you use the resister plug caps,you NEVER use resister plugs as well!!

 as it loads the system to much

[Ashdowner]

Final final comment is that on the NGK website it states that there is absolutely no effect on plug performance or potential damage to anything if you use resistor spark plugs with resistor caps.

[JamesH]

On the 750's the total impedance of each side of the ignition circuit should read 25 kOhms (assuming you use 5 kOhm resistor plug caps). So if you meter between ht leads 1&4 (with caps removed) you should get 15 kohms, and with 5 kOhm caps fitted you get the 25 kOhms total. I use this as a rule of thumb on both my 550's and 750's and has never let me down. This all assumes you're running non-resistor plugs (eg D8EA on the 750's). If you need to use resistor plugs (eg DR8ES) then use non resistor plug caps.

[Bryanj]

NGK are correct in that there is no difference in plug performance but there can be a difference in coil performance