Scooterotica

I'm trying out spark plugs for my engine.
Some have said here "Show us your spark plug and we will tell you how the engine is doing".
So now I need some help here. Eninge is GP 200, carb is 22mm Jetex. Mixture is 4%.
Left is a b8 and right is a b7 from NGK. Witch one should I prefer? What should I adjust?

are these both after plug chops at the same throttle position

byron wrote:are these both after plug chops at the same throttle position

They are both after riding approx 400km with each. different positions. Not a scientific calculated test. Just city road use.

Funny you should post this as I'm getting the same result on a 210 Casa 28mm delly and plug chops at same throttle (half open..................same plugs )

Theres enough plugs at various colours here to perhaps help out
http://www.dansmc.com/Spark_Plugs/Spark ... talog.html

rog60 wrote:Funny you should post this as I'm getting the same result on a 210 Casa 28mm delly and plug chops at same throttle (half open..................same plugs )

My best bet is to go with the B8ES and reduce the oil/fuel ratio to 2% instead of 4%.
I may be wrong, think I need a new B8es spark-plug to try that. I feel that the B7es is a little bit to hot considering I'm in 4% mixture.

i could be wrong, this is a first time for me

Useful Thackers, but these are the same carb setting results on two plugs of the same make, just different heat ranges............

If I remember correctly, B7ES is a hotter plug than B8ES so you are just seeing the result of a better 'burn ' on the B7 than the B8..........or that's how my thinking is going at the moment.

On a cast barrel, like yours, I wouldn't go down to 2%, maybe 3% unless your using a fully synthetic oil. Just MY opinion tho'.

In my case, the barrel is nicasil lined with alloy jacket so I'm not so concerned about seizes, more with piston crown 'melts'.

In the final analysis I'd rather the engine ran a little too rich than too lean.........

Anyone else

yes, maybe go 3% ?
also, there are some fake NGK plugs out there, posssibly don't give brilliant readings, there was a post on here with some information from NGK on how to spot them.
but yeah, I'd go for the 8 over the 7 judging by your pics

I'm not saying it is the case here or not but :
http://www.ngk-sparkplugs.jp/english/te ... index.html

kejj wrote: My best bet is to go with the B8ES and reduce the oil/fuel ratio to 2% instead of 4%.
I may be wrong, think I need a new B8es spark-plug to try that. I feel that the B7es is a little bit to hot considering I'm in 4% mixture.

i could be wrong, this is a first time for me

Colours on my screen aren't the best, if you can identify what each plug looks like on http://www.dansmc.com/Spark_Plugs/Spark ... talog.html it would be easier. Looking at my screen I would say that the B7 is more suited to the type of riding you are doing at the moment, if you want to richen the mixture a little then drop to a 3% ratio with the B7 and see how it feels. Use a B8 for longer faster rides.