Redneck 782cc

Airmiller44

MTB Guru
Location
Mesa, Arizona
Recently did a bunch of work to my 760 motor and had some questions. I thought there was a thread about this build and am looking for jetting numbers at 1000 feet above sea level. I thought there was a whole build process for this essential big bore 701 61x with dual carb and dual pulse.

Took a 760 and ported exhaust, opened up the factory pipe hole from manifold to head pipe, decked cylinder to 61x port timing, cut sleeves,matched the ada domes and am getting 180 psi like desired. It has the 61x cdi and lightened flywheel, carbon tech reeds, dual 44's currently have 115 pilots, 140 mains, 2.0 needle and seat and the black springs which is about 21 psi pop off. Its 782cc

She runs great down low but am wondering if im having pop off issues up high or if i really need to go fatter that 140's

Forgive my silly questions on my redneck build. This is in my cracked out fx1 with the 140 kawi pump/sxr impeller
 
Location
Stockton
At sea level my 865 8 mil with aftermarket 44's I was jetted 100, 125. 2.0 and 14 pop and was real crisp... 5 mil 820, same carbs jetted the same too...

I'd jet down...
 
Location
Stockton
Your total jet # per carb is 256

Mine is 225 in above examples

My Dasa 1200 with 49 fs is 260

Your total # seems to high

If you like the 116 then you can drop the 140 down..

What is the issue your getting
 
Last edited:
Location
Stockton
For my ported 771 I was told:

115/130
38-42lbs pop off

Quinc, yours is more reasonable and close to the revised builder specs for the 5mil 820 we have. Starting rich first, 117.5 L 1.5 seat 127.5 H, 1.5 seat 65g Spring....32 pop off...

My lamey 8 mil @200 psi ran so good with the same aftermarket 44's with 100L 125H 65g Spring, 2.0 seat and 14 ish pop off. I reseoned mine runs great how could this smaller Engine need more fuel, so I used the jetting that worked in mine and haven't had to do any jetting changes on the 820 in 17 hours. The owner is real happy with the way it runs....not running high speed wide open btw

The builder rides more high speed, we ride more rec and flat
 
Your total jet # per carb is 256

Mine is 225 in above examples

My Dasa 1200 with 49 fs is 260

Your total # seems to high

If you like the 116 then you can drop the 140 down..

What is the issue your getting

What's the specifics on your 1200 jetting? I run 50mm carbs and have 100m 150p 2.5n/s 115gm spring.
 
Top Bottom