CB550 spark plugs

[psycho_sis]

Hello.

Wonder if I could have some general advice and oppions?

I've recently got myself a lovely CB550F, 1978
My spark plugs have decided to stop working so I'm looking to replace them.

The Haynes manual suggests D7ES, on the web I'm recommended DR7ES and in the bike currently I have D8EA

Any ideas on what I should be using?

[L.A.B.]

NGK D7ES plugs would have been the original recommended plug which you can still use with resistor plug caps, the DR7ES is basically the same plug but they have the resistor built into the plug denoted by the 'R' so you would need to use them with non-resistor plug caps, if you are using red NGK caps then they are likely to be resistor type, this is normally printed on the caps (in small letters =5K[Ohms symbol] along with the cap model type)

NGK website lists D7EA as the standard plug:
http://www.ngksparkplugs.com/apps/motorcycles/make4.asp?id=1040&type=reg

D8 heatrange plugs may be a bit too cold, causing the plugs to foul when riding at low speeds.

[psycho_sis]

Hello.

Cheers for the information. You are right I do have the caps with the resistor in (It's easy when you know what you're looking for!!)

I have ordered the D7EA's. Looking forward to getting them and getting out now!

Thanks for the speedy response.

Kind regards

Caroline

[dunboyneroadracing]

most of the cb 400/550/750 s that i have ran have had dr8eas in them and they ran good.

[L.A.B.]

NGK '8's at least, being the recommended plugs for CB400F/CB750.