hey guys just pulled the plugs out f my project bike and they look like this, what does this colour mean? or is this normal?
(http://i60.tinypic.com/2nsynfs.jpg)
(http://i61.tinypic.com/ru7l0i.jpg)
It's running rich. It may be your air screws, or maybe you ride it at low revs allot? Are all the jets in the carbs standard size?
Yeh,... well it could be rich if it's a bit black and sooty, but if it's black and oily looking, that's something else - rings or guides.
BUT! ...
Don't fall into the trap of judging from plug colour unless you do a 'proper' plug chop. E.g. if you've just come up the driveway, and/or let it sit on tickover for a bit then pulled out your plugs, that plug colour will not indicate main jet or needle position setting, (Which is what you REALLY need to know), it will only indicate your pilot jet (tickover) setting (which is often on the rich side -blackish plug colour anyway).
There's a pretty strict routine for checking correct air/fuel mixture. You're wasting your time if you don't follow the routine, you'll find it, google it or youtube it.
Quote from: Joolstacho on September 22, 2015, 03:11:55 AM
There's a pretty strict routine for checking correct air/fuel mixture. You're wasting your time if you don't follow the routine, you'll find it, google it or youtube it.
My method of checking proper mixtures is pretty straightforward, jam my Innovate LC-1 probe up the tail pipe and read it (assuming catless). For a few hundred bucks it has been a worthwhile tool for me. But you are correct that if you want to use the plugs to gauge the mixture there is a procedure to follow in order to get more accurate results.