Rich, Junior, Pete, Anyone...Plug chop confusion

[gk45011]

Went from the shop tuned 127.5 main-40 pilot- shimmed needle- 4.5 turns out: Changed to: 135 mains-45 pilot- shimmed needle- now around 3 turns out each.

Plugs look the same side to side. Picture below. engine temp is running around 245 degrees while moving if that matters. With having changed the jets up (Mikuni originals, not knock offs), The plug chop actually looks leaner than it used to.

Unless I am way off base counter clockwise would richen up the mixture. clockwise would lean the mixture out on the bs34 carbs (yes, I know CV's are the devil).

I received two sets of carbs with the bike. Neither one had all the factory jets still in them. I know that the later model bs34 for this bike came with 40 or 45 pilots. By going up to the 45 pilot I have almost gotten rid of the off idle stumble.

Can anyone tell me if I am on the right track. Should I try a bigger pilot since I am not sure which was the factory setting? I also thinking about continually stepping up the main. It pulled hard and solid all the way up to 95mph then traffic on the highway thickened up and I had to let back out of it. It is cruising nicely at 75-80 mph at around 6500 rpm.

Does this look way to lean to anyone?

 

[SONICJK]

Hard to tell since youre focused on your mustang rim and not the spark plug ;D
But it doesn't look "way" lean, a little maybe.
Is that a plug chop? at what throttle position?

 

[gk45011]

LOL, sorry for the crap picture.

The chop is at a 4th gear WOT uphill.

I attempted a 1/4 throttle as well and they look very similar (used a different set of plugs)

I can always keep bumping up a little, just looked on the white side to me on both chops *not my strong point).

Gary

 

[crazypj]

That's fine, most people jet way too rich
Your looking at the body not the insulator, will need a couple of hundred miles for ceramic to colour up.
It's easier to use plugs that are too rich and see if they burn cleaner
I would check for air leaks if jetting up isn't having any effect
It is running slightly hot, the ground strap will have a definite 'line' when you have correct heat range and mixture


This is how my 360 looks after a few hundred miles

 

[gk45011]

Thats awsome PJ. Thanks to you all for the help! I'll try to turn the mixture screws out a wee bit more and see if that gets me where I need to be.

Gary

 

[oldskool]

I agree with crazypj. How does it feel through the entire rpm range? Put a few more miles on them and then see how they look.

 

[crazypj]

Mixture screws only affect idle and just off idle as bypass ports 'open'
After about 1500~2000 rpm, pilot jet is giving all it's got

 

[gk45011]

Starts with a little choke warms up in about 1-2 min. Pulling hard through all the gears up to wot. Tested this up to about 95MPH on an open area of highway last night before I caught traffic and had to let off. I will give the bike a few more miles and ten check the plugs again to see what the overall look of them is.

Gary