Carb tuning

[ahventure]

So I'm having trouble after a BBK on my Kymco Agility 50 getting the carb tuned properly. I've done a few mods at once, which I know can make it difficult to nail down the problem: 72cc BBK, Technigas next R exhaust, 20mm carb, free flow cone filter, plus CVT mods.

My problem is that I'm finding it difficult to get the carb tuned at all throttle openings. Basically when I do a plug chop at WOT, it always looks lean, as in there is no colour on the ceramic part of the plug. I've increased the jet size in increments up to 96 now, which seems wayyyy too big for such a small motor, but still can't see any colour on that ceramic part beneath the spark points. I've got it set to a good idle, but it feels as though it bogs down as the throttle is opened making me think the main jet is too big. I dropped the needle by one notch which has made it better, but it still bogs a bit.

I read somewhere that people have experienced problems with tuning when using free flow air filters. when installing mine i wrapped a layer of silicone tap around the air intake on the carb to ensure a really nice tight fit with no air leaks.

I've attached some photos of the plug after doing a plug chop at WOT. Let me know what you think of the colour.

I'm still in the process of breaking it in, but i am a little hesitant to run it if it's lean as it is my only mode of transport at the moment!

Any advice you guys can give me would be awesome!!

[ahventure]

Also forgot to mention: it's an iridium plug with a performance coil

[kz1000st]

Bogging isn't usually from too big a jet, it's usually the opposite. That plug is way too white and it's probably because of the air filter. To see, try wrapping part of the filter with duct or masking tape and see if it changes the way it runs. Also try fiddling with the idle mixture screw. It figures into part of the flow at higher throttle openings.