DragBikeMike
Serious Thumper
Offline
SuzukiSavage.com Rocks!
Posts: 4071
Honolulu
|
I did a series of runs with my GoPro zeroed in on the air/fuel (A/F) meter. With the engine up to full operating temperature, I recorded A/F at idle, 2500 rpm level-cruise, 3500 rpm level-cruise, 4500 rpm level-cruise, 4000 rpm up a grade, and WOT 3rd gear all the way past 7000 rpm.
After reviewing the videos to verify that the A/F was optimized, I reconfigured the carburetor back to the baseline and did the same series of runs with the GoPro zeroed in on the A/F meter.
I repeated this test several times, back & forth (UFO, no UFO, etc.) until I was satisfied that the data was consistent & repeatable. Note that it always developed the erratic idle in the UFO configuration, and always idled perfectly in the standard configuration. The rich idle issue isn’t a loose/leaky manifold, it’s directly attributable to the UFO.
Here are the results of those tests. The standard configuration and the UFO configuration were almost identical. BTW, the higher the A/F number the leaner the mixture. For instance, 12.0 represents 12.0:1 which is 12 parts air to 1-part fuel.
|