Kerker 4-2-1 No Baffle Jetting

[lankeeyankee]

Ok, I know most of you that run the Kerker 4-2-1 have removed your baffle from a time or two.. There is no sound such as this:eusa_dance:

The question is... Have any of you compared the A/F ration on a dyno with the baffle and without the baffle? If so was it leaner, richer, or not much of a difference to worry about?

The reason I ask is my buddy that raced his VMAX back in the day told me he was running no air filters, no baffle and ran 175 main jets,, and that VMAX did run good with the setup.

Thinking I am going to run with no baffle when I bracket race as a distractant to my oponent.

My therory on this (which may be bass ackwards)
Faster exhaust flow creating more / faster vac from the intake which controls the fuel being pulled from the MJ so = more vac = pulling more fuel= no need to jet or may run a lil richer:ummm:

 

[kaboom]

I am certainly no help on this....I am still trying to figure out how a better flowing exhaust and a more restrictive exhaust both cause a rich condition:confused2:

Seems backasswards to any engine I have ever dealt with:ummm:

 

[joelyons50023]

When i ran mine with no baffle it went way lean. just did it to see what would happen did not rejet so a 175 dj would be close.

 

[one2dmax]

richer the bulk of the time. Pretty much no discerable diff in power.

Sean

 

[lankeeyankee]

richer the bulk of the time. Pretty much no discerable diff in power.

Sean

Sean

Are you sayin it will run richer or I need to jet richer?:confused2:

 

[lankeeyankee]

When i ran mine with no baffle it went way lean. just did it to see what would happen did not rejet so a 175 dj would be close.

What did your AF ratio go from and to and what RPM's did you see the most dramatic change?

 

[EvilD]

What may be happening with out the baffle is you are loosing velocity, there by richening up the mixture. People associate this with loss of back pressure which is incorrect, it is loss of velocity. The exhaust was engenierred to be run with baffels, not open, if you were to design a open exhaust that maintains the proper velocity you will make more power. Clear as mud now?

 

[lankeeyankee]

What may be happening with out the baffle is you are loosing velocity, there by richening up the mixture. People associate this with loss of back pressure which is incorrect, it is loss of velocity. The exhaust was engenierred to be run with baffels, not open, if you were to design a open exhaust that maintains the proper velocity you will make more power. Clear as mud now?

You are correct to an extent exhaust velocity is just important as volume, if huber was around he could give you a 3 pg formula on this equation.
Backpressure is good at certain RPM ranges.....
I just dont want to take my bike to the dyno to have some douche bag over rev it.. i may ride across country to borrow Ragins AF meter though,

 

[kozy]

This thread struck my curiosity. I was going to jet my Max on my own, but A) couldn't get the float bowl drain screws loose and B) couldn't pry the carbs off of the engine. I was deathly afraid I was going to break something, so I took it to the stealer. He put 162 mains in it and all the guys I ride with say they can smell gas really bad when they ride behind me. I've got the Comp baffle in the Kerker, but hardly any packing in it. Should I drop a jet size?

 

[one2dmax]

If you aren't running my jet kit you need to be a lot smaller main. Stock is 152.5 and you should be either there or 150 (which will likely be closer for you). You won't be gettting max benefit without my kit or the stage seven though.

Sean

 

[joelyons50023]

Hey lankee look up my posts both pajs second page halfway down.

 

[lankeeyankee]

This thread struck my curiosity. I was going to jet my Max on my own, but A) couldn't get the float bowl drain screws loose and B) couldn't pry the carbs off of the engine. I was deathly afraid I was going to break something, so I took it to the stealer. He put 162 mains in it and all the guys I ride with say they can smell gas really bad when they ride behind me. I've got the Comp baffle in the Kerker, but hardly any packing in it. Should I drop a jet size?

Cant get the float bowl drain screws loose? Hmmm 10MM box end high qaulity wrench,,,,, 6PT 3/8 socket?? Couldnt pry the carbs up from the boots? Hmmm sounds like either you have athritis in your wrists,, very weak arm and hand muscles or POS tools or maybe even the wrong tools.

We dont know what air filter your running,,, or what jet kit your running, needles? etc... or when your buddies are smelling raw fuel low end mid range top rpm? when:ummm: Its raining out here so I am not getting great signal to my magic crystal bowl to see your bike from 400 miles away.

 

[one2dmax]

Lankeee, sometimes I wonder if you are smoking the burrito's and not eating them. Do you even know what the float bowl drain screws are? They sure as hell don't take a 10mm socket. It's a number 2 phillips and not uncommon to have them get stuck and strip out.


You are right about what is the current carb setup but I pretty much covered it all. If he's not running my kit he's way too rich. It doesn't matter what needles or filter if it's not mine.

Sean

 

[lankeeyankee]

Lankeee, sometimes I wonder if you are smoking the burrito's and not eating them. Do you even know what the float bowl drain screws are? They sure as hell don't take a 10mm socket. It's a number 2 phillips and not uncommon to have them get stuck and strip out.


You are right about what is the current carb setup but I pretty much covered it all. If he's not running my kit he's way too rich. It doesn't matter what needles or filter if it's not mine.

Sean

Ok Mr. Speedy Engine Remover, Slick Seat Maker.. I guess I dont know what I am talking about.... Maybe you are correct with the screw thingy..
I dont think I have ever drained my float bowls,, I have pulled the float bowls and replaced the screws with allen heads,, and yes the first time you are better off using needle nose Vice grips (new ones made by vice) which is no biggy just a little more effort.

If he wants to change his main jets he shouldnt even need to mess with the float drain screw.. Use a 10MM to remove me the brass bolt to access the main jet...

By the way.. Got a light?

 

[one2dmax]

Agreed, however most people like to try and go by instrucions printed in manuals and proper procedure. You are supposed to drain the carbs first before about anything else. Look from the side of your bike and you'll see a phillips headed screw on each carb which lets fuel flow from the bowl and out the little black hoses that stick out the sides.

Personally, I don't bother draining them either and take them off and flip them over and catch the fuel when it flows out the overflow hoses.

i'm sorry if i've got that much more experience then you and I can tell you don't like it. But, when you are on here trying to offer advice to others who are asking you can maybe make a better effort to give them correct advise.

I started like you way back when and learned then hard way as you are. eventually you'll get there and you've already learned a good amount. I had the Nitrous back in the early 90's (and still have one engine with it). I've blown up more engines then I care to think about but that helped me learn what we can do to make them last better. I tear the shit out of the bike but if I sell something to someone it's better then it would have been because of that.

Sean