jetting help

[rustee]

hello all great site i have already gotten some very usefull info here that has helped me out. i have a 05 tc full racing motor cam/port/13:5:1 piston stk bore full curtis sparks exhuast/ kn air filter no lid on box 41 fcr carb about 400-700 ft elevation.
c12 race fuel we race flat trac and tt
main 195
pilot 52
needle stk position
screw 2 turns out

i am still running too lean plug insulator is pure white and little deposits on bottom of plug base were treads end definatly running hot.exhuast header is getting purple. i cant beleive that i need to get up to the 200-205 main range or higher any info would be greatly appreciated. dont want too wast my motor. i have read the jetting faq but it dosent seem to apply here.also the jetting forum on what others are using nothing too my size. thanks rustee.........

[tltcracing]

try the upper jets. going richer really doesnt hurt anything but staying lean does.

[jkirk141]

im running a setup pretty close too that w a 170
i had problems jetting at first because my valves were too tight you might wanna check that.. everytime i would check the plug looked white and grey becuse the intake was way to tight and wasnt letting enough gas in... i would go over a 180 w that set up

[GPracer2500]

I really don't like jetting with plug readings. Too often you'll be chasing your tail. I've seen several threads recently where folks have kept going richer and richer (way richer than they should be) because their interpretation of the plug kept saying lean.

...but if you are using plug readings, be sure the part you're looking at is the very base of the insulator--way down inside the plug. It's really hard to see without a plug reading tool or cutting the threads away.

[rustee]

thanks for the reply guys!!
i put in a 200 main went 2 1/2 turns out ran strong then started to breake up a bit on top end. turnes screw back to 1 3/4 tryed agai thing riped no more breakup very responcive. did not get to pull the plug yet to check it out will look tommorrow. was thinking going to a 55 pilot from a 52 and comming back down to a 195-190 main and see what it looks like i will know more tommorow. we are racing nationals at birch creek saturday the 8th and really need to get this think done. again thanks for the great info. rustee....

[leadfoot_52]

I'd say put in a 195 main and leave it. I tried my 06 with different jets, and the plug color was still white even when it was cutting out (rich Mixture) with a 178 Main. I am now running a 172 main, and it's perfect. You should be able to tell by going like 10 mph in 4th gear, then mash the gas and try that with adjusting your needle. also remember if you are running race gas your plug will look white or even grey rather than a normal "Tan" color with using pump gas. It may take a while (it took me 3 Hours of messing with the needle clip postion), but it is well worth the amount of throttle response.