How much will a KN High Flow air Filter Affect the mixture?

How much will a KN High Flow air Filter Affect the mixturefrom the carbs?

It is brand new.

I noticed the differnce in performance right away.

Why use one of these air filters, is a stock better?

Otherwise stock KZ650 B2.

One more question, Plugs are sooty , dry black? B8ES is what I use, will a B9ES be better or B7ES?

I've been running a K&N with stock air box for 28 years. Some people may disagree but K&N filters have been proven to out flow any other filters out there and clean the air better. Also in 28 years I've only bought one filter ($11.00)! A minor mixture screw adjustment should be all you need. As far as your dry sooty plugs it sounds like your a perfect canidate for WG's coil mod !

The B8ES aren't the correct plug, the B7ES are. If I'm remembering my NGK plug numbers correctly the B8ES are a step colder plug (I remember thinking it was odd that the hotter plug had a lower number). Not sure if the colder plug would contribute to the black plugs or not, but I'm sure it can't help any.
+1 for doing the coil mod, made a HUGE difference in how my bike ran.

I've never been impressed with the coil mod. True, poor or corroded connections can drop coil voltage but I've always been able to get it back with a little maintenance. That said, go ahead flame away, I believe that the 8's are the stock plug. I always seem to end up with 7's. I like the mixture a bit rich to keep temps down with a one step hotter plug to keep the soot off.

KZCSI

Not flaming at all, but all of my reference material (my owners manual from my 77, my Clymers and my Factory Service Manual from the 81 CSR) all call for the B7ES as the stock plug.

And yes, going through every connection and every wire on the loom and ensuring clean connections and good wiring will ensure full voltage to the coil, it's just a lot more work than doing the coil mod to attain the same end.

Not trying to pick a fight here at all, just putting in my bits.

If you have 12 volts at the coil the mod isnt needed. I had 11.1 on my 1105 78KZ and it was a night and day difference with the mod giving 12.2 at the coil

Based on my experience with my '77 KZ650-B1, the WG Coil Repowering Mod was necessary, it eliminated the sooty plugs symptom as well as the hard to start/cold blooded symptom.

My 2 cents worth.

I measured only 10 volts going to my coils. My battery registered in at 12.56 volts so somewhere within my wiring I am losing at least 2 volts to the coils. For me, the coil mod makes sense as I do not have the time to chase down the voltage drop through my entire loom. I was able to piece together everything I needed for the mod right at about $10. So the price and immediate benefits of the mod is what sold me. Just my two cents.

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Needed and necessary vs. desirable are completely different. I think the coil mod is desirable since it takes out the possibility of old wiring and connections making a bad thing happen. For the cost and amount of time involved for me it's a no brainer (I get along good with no brainers...we are equals!). I was taught one of the first thing you should do with these older bikes is to go through the wires and connections. But I still say if I can make something better and that includes the coil power mod I'll do it. It beats not riding, getting crappy gas mileage/performance or pushing a beast home. IMHO of course!

About the K&N air filters, I was in an auto parts store the other day, and they had this rather convincing K&N display on the counter. It was a plexiglass plenum box with a fan in it, and on top of it was a plexiglass tube with a ping pong ball in it. On front of the plenum box was a square hole that held a filter. One filter was a stock looking paper filter, the other was an equal sized K&N filter.
With the paper filter in place, the ping pong ball hardly moved at all. But when you replace it with the K&N filter, the ball would rise all the way to the top of the tube, demonstrating much more air flow than the paper filter.
So I was kinda wondering if I switched to K&N pods from my cheapo paper Emgos, would there be a dramatic increase in airflow requiring yet another jet change?