Lean plug!

[stonerosesmod]

Hi all,

Just changed my JL3 to a Franspeed supertourer exhaust on my smallblock mugello 200.The JL3 ran fine and showed good jetting across the range,but just went for a blat down a local road around 60mph and did a plug chop and got this,



Plug looks way too lean for me,and it was cruising for about a mile or so bang on mid throttle as ive taped and marked the grip.

Running a 26phbh with breathe sweet filter,

53 Pilot
AV266 Atomiser
X7 needle on 2nd clip
122 main

B8ES plug (new around 20 miles ago)

I just tried moving the needle clip down to the 3rd notch but it was really boggy and wouldnt pull cleanly through the gears so put it back to the 2nd.

Any ideas chaps?

[Donnie]

What colour was that plug before the exhaust change? I ask because i suspect you'll say dunno as it is new?
Muggy plugs take a while to colour up usually so may not be a true plug colour?

If it was true you may have to keep the x7 and go to an av264 then play with needle position again?

[stonerosesmod]

Must admit i changed plug when i changed pipe.Doh!

Camlam site suggests an AV268 for my set up? I may have to try the old B8 plug in and give it another chop on the same road,or maybe a B9?

[Donnie]

I'd put in the old plug, put the needle back to boggy and see if it will clear. If not, move the needle to one position leaner (down a notch) and repeat. Then you can start thinking about different atomisers.

[stonerosesmod]

Sod it, I might ring chalkie up tomorrow and try gettingit booked in soon!

[stonerosesmod]

Looks like it was a new plug throwing me out.Had it dynod and was really rich with on top end even without the filter.Went from a 122 main to a 119 and still really boggy.Tried again with a 116 and it ran a lot cleaner but slightly rich now.Wont rev out as much as the JL3 but thats the exhaust.Ill try it on the road if it stops raining!

[Donnie]

Thought it might have been. Glad you're sorted