Lean condition

[bro.betterley]

I may be making a big deal out of nothing but my right rear exhuast header on my marks exhaust is blue ( indicating lean )

Should I ignore it, all my plugs read a nice light grey, but only one header is blue, the bike runs good no stumbles.

Were would you start to figure out what is making it so lean, heres the details on my bike, carbs were stock whem i got it, they were never touched.

My floats are between 16-17mm, all jets stock, marks 4 into 2 exhuast, new factory oem slides and diaphragms, stock needle shimmed 22 thousands, factory springs with 3 coils tied of, idle screws 3 1/4 out, Factory air box with spacers in the "Y" (if i remove "Y" stumbles bad in upper RPMs)

It has a good carb synch at 3,500 RPMs


On a side note the header that is blue is also the cylinder were notable vmax noise seems to be coming from that i posted about, in another thread, it dosent seem to get any louder when you increase RPMs, the chatter has been there since i got the bike 3000 miles ago, it now has 23, 000 miles on it

Do you think it could be exhaust leak even if i cant feel it with my hand?

 

[KJShover]

Do you think it could be exhaust leak even if i cant feel it with my hand?

Its possible. over the years I've had many header leaks that I couldn't feel with my hands. I now use a stethoscope or a long, lit candle.
It could also be from long idling and lack of the cooling air flowing around it.

If your plugs are looking good and it's running fine, I wouldn't sweat it too much. If you have a digital thermometer you can aim it at your pipes to get a feel of where your at in the heat range then tweak your a/f a little to soften up that cyl if needed.

My Kerker's have a slight blueing, with a nice gold color, in the back. but I know my tune is good. Just the nature of the beast. Lack of airflow in that area vs the flow up front.

 

[bro.betterley]

Its possible. over the years I've had many header leaks that I couldn't feel with my hands. I now use a stethoscope or a long, lit candle.
It could also be from long idling and lack of the cooling air flowing around it.

If your plugs are looking good and it's running fine, I wouldn't sweat it too much. If you have a digital thermometer you can aim it at your pipes to get a feel of where your at in the heat range then tweak your a/f a little to soften up that cyl if needed.

My Kerker's have a slight blueing, with a nice gold color, in the back. but I know my tune is good. Just the nature of the beast. Lack of airflow in that area vs the flow up front.

Thanks for the imput, but could you help me understand the red portion better?

 

[KJShover]

Thanks for the imput, but could you help me understand the red portion better?

I was talking about using the a/f screw to throw a little more fuel at it to richen the mixture.

If I remember right, the earlier Gen 1's used different jetting the in back two carbs than the front. I think this was the factory's way of cooling down the rear down tubes. If I'm wrong I'm sure another will pop in and correct me.

 

[tugla]

you are right KJ, think 85 or something like that had staggered jets

Bro, i think your bike is fine and normal, plug read first and if all good dont worry. my kerker also has a slight blue and its seems to have been like that for a while and not chg too much.

 

[KJShover]

you are right KJ, think 85 or something like that had staggered jets

Great, I'm glad my memory isn't fading as fast as I thought.

+1

If the plugs look good and the bike runs fine I wouldn't sweat it.

 

[Thevmaxrider]

I was talking about using the a/f screw to throw a little more fuel at it to richen the mixture.

If I remember right, the earlier Gen 1's used different jetting the in back two carbs than the front. I think this was the factory's way of cooling down the rear down tubes. If I'm wrong I'm sure another will pop in and correct me.

This was used to make up for the different header lengths between the front and rear.

 

[KJShover]

This was used to make up for the different header lengths between the front and rear.

Cool, Thanks Jim. I, for the life of me, couldn't remember why. :clapping: