Light brown plug

[james]

I am changing the jetting on my PX125 after fitting a new JL type exhaust. I went from 96 with my standard exhaust to 98 fo rthe new one but the plug is light brown. I changed the jet for 100 and took it for a short run but it is still light brown.

[Smallframe]

lend a mates p2 116 main (is it black now ?) and come down in sizes till you get chocolate brown. Brown is good.

A Caramac is a little lean

A Bourneville is a litle rich

A Galaxy is bloody lovely "if you get my Drifter " ;D

[Lucia]

Caramac is the new black. Only buy 3 at any one time.

[bryno]

Caramac, blimey they started making those again??

Colour sounds fine mate..

But you wont really get a proper reading on the main jet on a short run, you need to do a full throttle test, ideally 2 miles on full, then kill the engine, coast to a stop, smoke a fag, when cool check plug.

[james]

Thanks Bryno. Do you think light brown is ok from a short run? I will thry the all out then kill the engine chop soon. I tend to do 2 miles flat out on my home from work.

[dto79px]

after a short run only i would expect the plug to be darker , almost black sooty

[bryno]

^ problem with a short run or anything other than a full throttle cut is the other jets also effect the mixture, so on your 2 miles home it may well have been running very lean when flat out, then as you come off running mostly on the main jet the mix could be back to normal, so by time you have got home the plug looks fine..