i finally got around to doing the plug chop...
ds just isnt running tip top and SEEMS to be lean...so i did this to try and figure it out...

my mods are WB pipe, KN, Big gun cdi. usually ride at about 800 ft above sea level, currently have it set with a 175 main (mikuni) and needle in the 2nd richest postion. (top of the needle is the leanest, making bottom the richest correct?)

Smokes on start up (black, not blue) seems to be hot...but plugs were blackish....

here is a link to the pictures...sorry my camera has horrible quality for really up close shots.... the plug on the left is what i have been running for the past few months, the plug on the right is from the plug chop.

Plugs


Plugs * 2

On the sheet i printed out on performing this, it said the Porcelain should be the tannish color.... Is that the porcelain inside the plug? or the main porcelain that surrounds 1/2 of the outside? (im assuming inside?) the porcelain on the Inside of the left plug is completly black (as you can probably tell from the heavy layer of soot) and the one on the right from the chop is completly white....)

would this mean that i am Lean on the top end (need to go to a larger Main jet,) and Rich on the bottom end? (need to lean out needle, and possibly switch pilots?)

not 100% so wanted to see what you guys thought, before i went and started changing the wrong thing...!

 

cant see the pics very well to tell one way or the other

so did you chop it at wide open throttle in a high gear?

sounds rich,,,,and if you chopped,,,it is most likely your main jet that is rich

 

i went up the 1/4 mile lane at about half throttle, than came back down PINNED in 5th, for about 4-6 seconds, held clutch in, hit kill siwtch, and then checked it.

The porcelain is Completly white... not a single bit of darkness on the inside at all

i thought plug chops were supposed to tell main jet condition....if it does in fact, than i beleive im Lean on top (if i was rich i would assume the porcelain would be really dark...)

 

I see now

I read your post wrong

yup, lean

 

you may want to find a longer stretch,,,,,with an uphill grade (to give it a load)

Im sure the Bomb guys will have you fixed up in no time

bigger main jet sounds like

 

would this mean lean on top (main) and Rich on bottom? (pilot/needle?)

i plan on going up one size on the Main (probably a 180 mikuni)

 

Roost it takes quite a while to get color on a new plug in this motor, if that plug from your chop was new then there would be no significant color to tell anything by in just a couple runs. It takes a good days ride to get color on to tell anything.

The old plug that is black shows you're rich somewhere, but where is the question of course, ie. main, needle clip, idle mix. If its really fouled it may not clean off in chop run, so I recommend running that new plug for a while to start turning its colors and then doing your chops again.

A very common cause of plugs blackening is a maladjusted idle mixture screw - jetting can be spot on but the soot gets deposited at idle a lot. set the screw by turning it in til the motor bogs, then out til she bogs again, and then set midway between those bogs. If this screw is rich that could explain your smoke at start up too.

FYI one tip - the muffler end is a direct representation of plug condition - if the muffler is blackened with soot then so is the plug. if the plug is right cause the mix is right the the muffler cap with have a dull gray coat.

 

I thought the point of the chop was to tell color, because if i rode say an hour on the new plugs, wont it just get dark again? (due to it being rich Somewhere in the circuit?)

you said to do a chop after riding it for awhile, if i pull it after an hour of riding, do i try to clean the porcelain, and THEN chop?

im a noob on like 90% of this stuff... lol only people i can get FREE help with is you guys... (my local shops would probably charge me for the time it takes them to answer the questions...lol)

 

hey hightower, i just looked at your pics, who did your seat? it looks awesome

i wouldnt mind getting one done like that in black/orange. What did it run you?

 

If it smokes on start up you are way to rich on the bottom end. Pull the K&N jet kit out and put your stock needle back in. Set it at the 5th (richest) position and use a #175 mikuni main. Air lid on. Air screw 2-3 turns.



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