I was originally using a honda crf450 fcr-41 mx, running the jets at 168 main and 68 pilot (way rich) with a oecbl needle (or something odd like that)
My xr started first kick idle mixture screw 2 turns out it was so Snappy and responsive and burned a perfect golden brown on the plug. Due to fitment issues and the float beginning to stick, I swapped for a FCR41 Sudco carb. It fit better and with the same jetting but a different needle it ran STUPID rich.
Set the float, and cut back to 160 main 55 pilot. Still ran really rich all the time.
SO; I look at the AP squirter, and my old carb would spray for about 1-1.5 seconds with a pretty good blast, just enough to spray when you start to open the throttle til the slide is up about id say halfway and stop.
The sudco carb> starts to spray as soon as the slide is moving and sprays for 3-4 seconds a huge insane powerful blast. :thumbdown
There are no AP duration adjustments on this carb like there is the MX.
That means on and off the throttle I was pumping assloads of fuel into the motor with no chance to burn it off = running stupid rich. Also my pilot is a bit on the rich side for easy starting (havent played with starting jets and what not yet).
When you whack the throttle open it would give a kind of "braapuuuuhhhh" sound until the higher rpm range where it would really scream.
My solution? This was just way too simple.
I took the AP diaphram from the fcr mx and used it in the sudco fcr. This is not as obvious solution as it would seem, almost nowhere online in any of the tuning manuals did it mention different AP rubbers.
The rivet on the fcr mx stops the diaphragm about middle of its stroke. The sudco pump would push WELL below its mid stroke until it would bottom out.
Swapped them, and used the obel needle from the fcr mx and oh my god!
This thing is SO much SNAPPIER and RESPONSIVE! I can hold 2-3 gear wheelies and THIS BIKE SCREAMS. It seems to have lost some on the top end assuming the needle is responsible for that.
I have 2 friends with SXC's with the sudco carbs, and I plan to pass the info along, the stock diaphragm just pumps WAY too much fuel. The oem honda is really the way to go.
My xr started first kick idle mixture screw 2 turns out it was so Snappy and responsive and burned a perfect golden brown on the plug. Due to fitment issues and the float beginning to stick, I swapped for a FCR41 Sudco carb. It fit better and with the same jetting but a different needle it ran STUPID rich.
Set the float, and cut back to 160 main 55 pilot. Still ran really rich all the time.
SO; I look at the AP squirter, and my old carb would spray for about 1-1.5 seconds with a pretty good blast, just enough to spray when you start to open the throttle til the slide is up about id say halfway and stop.
The sudco carb> starts to spray as soon as the slide is moving and sprays for 3-4 seconds a huge insane powerful blast. :thumbdown
There are no AP duration adjustments on this carb like there is the MX.
That means on and off the throttle I was pumping assloads of fuel into the motor with no chance to burn it off = running stupid rich. Also my pilot is a bit on the rich side for easy starting (havent played with starting jets and what not yet).
When you whack the throttle open it would give a kind of "braapuuuuhhhh" sound until the higher rpm range where it would really scream.
My solution? This was just way too simple.
I took the AP diaphram from the fcr mx and used it in the sudco fcr. This is not as obvious solution as it would seem, almost nowhere online in any of the tuning manuals did it mention different AP rubbers.
The rivet on the fcr mx stops the diaphragm about middle of its stroke. The sudco pump would push WELL below its mid stroke until it would bottom out.
Swapped them, and used the obel needle from the fcr mx and oh my god!
This thing is SO much SNAPPIER and RESPONSIVE! I can hold 2-3 gear wheelies and THIS BIKE SCREAMS. It seems to have lost some on the top end assuming the needle is responsible for that.
I have 2 friends with SXC's with the sudco carbs, and I plan to pass the info along, the stock diaphragm just pumps WAY too much fuel. The oem honda is really the way to go.
