How does this plug colour look?

[RWN50]

Hi guys,

I'm not a plug reading guru by any means so looking for some info from people that know what they are looking at.

These 2 different plugs (first copper, 2nd iridium) are new out of the box and 3 passes old (couple of minutes of wide open throttle, then turned off straight away and checked)

Motor details -
Tohatsu/Nissan 50hp (700cc 3cyl 2stroke)
Shaved head
Ported
Tuner
Reeds
Standard airbox
revving to 7000rpm

I think they look a tad lean?

Thanks in advance

http://i62.tinypic.com/bgyck5.jpg
http://i61.tinypic.com/rtkpja.jpg
http://i58.tinypic.com/betwt4.jpg
http://i57.tinypic.com/34y1x8i.jpg

[Krazy Karl]

They look pretty lean to me. Also from something an old boat racer show me it looks like your timing is way advanced.
kk

[RWN50]

my timing has been brought back 2 deg less that standard

[Fastjeff57]

I've seen a few plugs that looked that way, yet the motor ran okay. The reason why is ethanol fuel--it "looks" different.

My late buddy's drag car ran on pure methanol, and there was absolutely NO color whatsoever on the plugs.


Jeff

[zul8tr]

Tell us what fuel, oil and oil ratio you are using.

[RWN50]

98 octune unleaded. Mineral oil run at 40:1

No methanol or ethanol blend

[zul8tr]

98 octune unleaded. Mineral oil run at 40:1

No methanol or ethanol blend

Is that E free fuel. What brand
mineral oil?

[Fast Fred]

i'm seenin , needs more fuel. best to keep bumpin it up till the boat slows down, then go back a bump or two,

[MWhite]

Hi guys,

I'm not a plug reading guru by any means so looking for some info from people that know what they are looking at.

These 2 different plugs (first copper, 2nd iridium) are new out of the box and 3 passes old (couple of minutes of wide open throttle, then turned off straight away and checked)

Motor details -
Tohatsu/Nissan 50hp (700cc 3cyl 2stroke)
Shaved head
Ported
Tuner
Reeds
Standard airbox
revving to 7000rpm

I think they look a tad lean?

Thanks in advance

http://i62.tinypic.com/bgyck5.jpg
http://i61.tinypic.com/rtkpja.jpg
http://i58.tinypic.com/betwt4.jpg
http://i57.tinypic.com/34y1x8i.jpg

What kind of fuel mixture/oil u running?? different oils will show alittle diff. on plugs, but it does look to be lean. I think i would bump up your jets size and read them.

[mercguy]

163 or 165 main jets?

[RWN50]

Thanks everyone for the info. The 98 octane is not an E fuel its just pump gas over here in australia.
using Valvoline mineral oil at 40:1

Mercguy, they are the standard tohatsu jetd which are 132 or 135's i think from memory.
What are tou running in the one in you avatar?

[Fastjeff57]

Yikes! That sucker is really running lean. At least there's no aluminum flakes on the plug ceramic.

Jeff

[mercguy]

Thanks everyone for the info. The 98 octane is not an E fuel its just pump gas over here in australia.
using Valvoline mineral oil at 40:1

Mercguy, they are the standard tohatsu jetd which are 132 or 135's i think from memory.
What are tou running in the one in you avatar?

run 135's in all 3 carbs............I run 32:1................what heat range plugs are you running? How much is shaved off the head? I build lots of the M50 Tohatsu's for racing..

[RWN50]

I PM'd you mate

[RWN50]

mercguy - I PM'd you but no response not sure if there is a problem with messages or not.

Can you tell me more about the M50's that you build? are you using stock fuel pumps still, a few guys a changing to 3cyl jetski ones. Do you always use standard 135 mains?

Im using NGK BR8HIX iridium plugs. heat rating of 8.

1.2mm off the head or nearly 50thou

What revs are you achieving out of your motors?

any advise would be great.

feels like its surging slightly with lower pitch props above 6800