Saving Old Seagulls

On my century plus standard plug is the d16 I believe but been recommended to use the d6 or d6a. Your thoughts welcomed

Equal to D16 is NGK AB6. I use two of this on my two silver century with success. I don't know the types you are referring at.

A Champion D9 was recommended by some for continuous hard running, because it was a cooler plug. So if a D6 exists in a Champion this would be a cooler plug again and would almost certainly be a bad idea, as it would most likely not burn clean and oil up. A D21 is hotter than the standard D16 and is used by some in light usage where a hotter plug can perhaps stay cleaner. As others have said the NGK AB6 is equivalent to the Champion D16, perhaps that's what people are suggesting to you. The D16 or equivalent seem to work well for most, myself included, so I'd stay with that, or an equivalent to a D16 in another brand - no point in trying to reinvent the wheel.

NGK plugs are superior to Champions in my experience and opinion. Especially if you expect easy starting, although I must admit that my Seagulls seem to tolerate Champions better than my OMC motors.

I have always preferred to use a vintage spark plug with a vintage motor, I use mainly champion's or Lodge's.
Some of the OMC motors have odd rated plugs and can be hard to got hold of over here, especially when I had to pay £5 each for a NGK plug.
I suppose Champion plugs have been around for years and NGK, is a pretty new plug.
I prefer the two piece plug anyway, never had a problem with them.

I always found back in the late 70's that NGK plugs were superior to Champion in my motorcycles, after a couple of thousand miles the Champions would be wearing significantly, the NGK's seemed to last almost indefinitely. For that reason I've always gone with NGK to this day, although I doubt in reality the same differences still exist, I've always felt that was probably just a glich in time where for some reason NGK had some better technology, and they were the OEM fit on Japanese bikes. Those were the days where plugs were changed every 12,000 miles in a car, now the pickup trucks we buy at the dealer auctions with over 100k on the miles usually have the original spark plugs in them because they keep working and no one bothers to change them. The change interval is specified as 75k on some. Even the lowly spark plug has evolved quite a bit in my motoring life time. Having said that I recently replaced two new looking Champions in my 79 Chrysler 7.5 outboard with NGK's and the starting improved dramatically, but then again the motor was practically unused from new and so they were almost certainly 1979 Champions, so I guess that proves nothing.

The only 2 piece plug I have is the original that came in one of my 40+, currently I run an Autolite D16 equivalent and keep the original as a souvenir

Bought 2 x NGK AB6 in the end lol

Loiner1965 wrote:Bought 2 x NGK AB6 in the end lol

Yours must be the very rare Century Twin Cylinder then?

lol.........brought one as a spare

Loiner1965 wrote:......brought one as a spare

So you have two Twin Cylinder Centurys - Wow - sorry just being silly

Always a good idea to have a spare spark plug and I always keep one on hand in the boat, although I've never have had a plug problem on a Seagull - sticking my neck out now with that statement, I'd better get a case of them LOL.

My Century Plus runs perfectly well on an NGK A-6 is this the right plug?

Neal

Perfectly fine, Neal. That and its replacement the NGK AB6 are fine.