Thanks for the heads up but I will stick with what I know
works for me
from my automotive experience more torque and throttle response
with a low rise manifold than a hi rise manifold
Look at your motocross bikes the cabs are slammed up tight to the head
on your sport bikes the cabs are tight against the head
motocross is all about low end grunt you never see a Mx motor with a crab hanging off of a long intake track

 

I'd think carbs mounted close to the engine is more about lack of space to do otherwise on most bikes.

Get the FCR35 sorted out and let's hear how it's running

 

New day of AFR testing getting the lean out
This carb showed up with a
r needle
168 main
45 pilot
Adjustable slow air jet
This is where I am starting out
I got some time to put into the cow today
I am waiting on parts for the first carb that I bought that was the
wrong one it has been sold and is going on a DR650 suzuki that is
here for some up grades

 

trust me it ain't about a lack of space
changing the height of the carb or using a side draft up draft down draft
carburetor will make the motor behave in different ways that you can take advantage of to set the bike up for what you want it to do
I am not trying to sell a carburetor good luck finding one,most normal people
would just bolt on a mikuni and call it a day and thats great it is a wounderful up grade for the ol klx this whole thing is to give me something to do while I am waiting on parts for the other stuff to do
and for the 1%ers who want to take a walk on the dark side
but so far the little black klx motard is starting to act like a tard.

 

Done for the day
I had to change up the needle took out the r and went to a p
I have also ordered some pilot jets 50 52 55
to fix the mid range lean
now I am waiting on parts for 3 bikes
so many parts so little time
On ward through the fog

 

You'll notice the typical lack of space mentioned here, and how the MV Tamburini's moveable extension bellmouths lift off the short stacks above 10,000 rpm shortening the intake tract length to add top end power.

Also mentioned is how designers can get a 2 or more intake waves down a short intake etc

- That may be a different subject than where to place the carb along an intake tract that's going to be a fixed X inches long regardless of whatever distance the carb ends up being though.


I already have a 36 & 40, so I'm not in the market - just waiting to hear how it works out for you

 

I under stand I am not trying to sell a carb this one is for my wifes bike but the length of the velocity stacks are different than how high the carb is set off the head
back in the sixty's when we ran hillborn injection on the small block chevy the short stacks were for top end and the long stacks were for down low grunt.
and you could tune it any where in between

 

Richard here is a thought
I'm not trying to tell ya what to do Lord knows
I have a hard enough time just trying to figer out
what I'm doing but that being said
I don't know that much about the Mikuni carburetors I dont work with them that much
But I work with the mikuni EFI all the time, in my humble oponion it has it all over the Keihin
locked out EFI system so
I always ran the Keihin carbs cause they were cheap and there are
a bunch of them out there,some one is always blowing up there motor cross
motors they give up and part there bikes out
But back to the thought
Does your mikuni's have removable intake bells
Bill.

 

2 fcr going on
one on klx one on dr650

 

No none of the Mikuni pumpers do; and both the 36 and the 40mm fit with the existing KLX connections at either end perfectly btw


I guess the Keihin FCR has a leak jet in the AP system, which could be an advantage for tuning; but some of them have no choke?

Other than that both brands have the same systems for the most part