2300 Sea Level Jetting, White Plug
 

Hi,

I just did the first stage of mods to my buggy and now jetting. I added following:

Uni Filter with 6" Tube
12G Sliders in a 118 variator
NCY Clutch with Ban Jing Bell
Performance exhaust, similar to supertrap with disk
Iridium plug
Cdi Adjustable Performance Box
Performance Coil
Kevlar drive belt
I have what I believe is a 24mm carb that looks like keihin with 'Mikuni' On side.

I have put in a 135 main jet and my plug is still almost white with barely any tan at all. I am at 2300 above sea level so I am shocked I am at 135 with a white plug still. I checked for air leaks and nothing. Any thoughts on it? Seems also like the 135 does not run as well as the 130 I had in it. However, that 130 was real white.

Charles

if you have any spare plugs, take and do a cutaway to see what it looks like further down the ceramic. a lot of times with the ethanol added fuel you will be running fine but not getting any color up on the tip. likewise seeing that you have a supertrapp style exhaust, try tuning with the disks to see if you bring up some color.

I think when I don't use Iridium plug that it is more brown.

What procedure are you using to check color? You should always use an old plug that is already colored, this makes for an easy read. A new plug will take time to color.

Hi Sycarms,

I am using brand new Iridium plug. Seemed to run pretty good at 125 jet but then boosted to 130 and 135 and was not running good. However, the plug was still so white. Ran it around the block and back.

Also, I am still going to be sending you my head and manifold for porting and polishing, can't wait. Just got my aluminum manifold for it.

Charles

Your first and main concern with mixture is with wide open throttle for this is what burns up an engine by overheating it. Unless you have the equipment to check the A/F mixture the only accurate way to check is the WOT run. You will need an old colored plug and a strait run of 900-1200 feet,(phone poles are 300' apart). First you will loosen your plug and then lightly snug it down, this is so that when you remove it to read it is not so tight that you pull threads out with the plug. Bring your plug wrench with you. With engine at operating temp from a dead stop accelerate to full throttle for the 900'-1200' run never letting off full throttle. Once you reach the 900'-1200' mark with your throttle still in full open turn the engine off. Only after engine stops do you lift off of full throttle. This makes sure your plug will only read at full throttle and not idle circuit. Pull your plug and read by inspecting for color around the rim right above the threads, the ground strap and porcelain. If proper it should read anywhere from a light tan to a medium brown. You should also make sure your compression is good, a worn or too tight valve setting can give you a lean mixture.