Few clues in the text. Plugs = more than 1 cylinder Synch carbs = more than 1 carb and not injected. Avatar pic of a FZR400 = 4 stroke. :whistle:
I'd guess that's just a crank breather, They usually don't connect to anywhere. (But don't take my word for it!)
Your never going to be able to set anything other than tickover fuel with colourtune or similar unless of course you can see the 'colourtune etc' whilst holding a steady throttle at speed lol.... Waste of money imho.. Get it on a dyno.. What does it matter if its running slightly rich or lean at tickover? Are you spending a long time stationary?
Plug chops is the old way of getting a rough idea of mains size, done at max revs under load so preferably on a hill then cut engine AND PULL CLUTCH. Take plug out and see what colour the centre is. tan is good white is lean black is rich. All very difficult as you will find out when trying to get an accurate reading... makes no difference if itas a multi, 2 stroke, 4 stroke or whatever, unless its a single carb fueling 2 cylinders..
Use the colortune to sort out idle mixture. If the midrange and top end are still too rich you'll need to check the condition of the float needles, check if the emulsion tubes have gone oval and if anyone has mucked with the jetting in the past.
This way always works for me: Gather six birch twigs on the night of the winter equinox. At midnight on the next full moon throw them into the air while chanting chuga chuga chuga. If the twigs land exactly parallel to each other, it means your mixture is perfect. If they land in a messy, random pattern..... Book a Dyno run.
Haha do i need to dance around a fire while doing the chant and will a dyno will tell me why its spluttery when taking off slowly or how much power its got ?
Fire dancing is a bit more advanced. This is for electrical problems. But yes, a Dyno run will show the problem up. There is a very good place in Warrington called Hammer and Tongs.
Vacuum leak, like I said. You have the right symtoms. Spray carb cleaner around the intake stubs and vacuum hoses, if the engine picks up speed there's your problem. Get out there and check.
http://www.factorypro.com/tech/carbtun.html That method is far better than plug chopping for tuning your fuelling
Doofle your a leg-end ive just watched a video on vacuum leaks he test drove a cb 750 with severe leaks and its very similar nice one
