I just thought I would share the results of some testingthat I carried out.
I followed the same procedure that KSRRider2 used, 10 oz in a clear plastic bottle, and used a stop watch to record the amount of time it took to fill to the 10 oz line. Here are my results;
These are with stock petcock, stock tank and hoses.
With 90 degree visu-filter, Petcock in on position, full tank of gas, - 32.18 seconds to the mark.
For the rest of the testing, no filter was used.
Petcock in ON position, half tank of gas – 18.88 seconds to the mark.
Petcock in ON position, full tank of gas – 17.22 seconds to the mark.
Petcock on RES position, full tank of gas – 17.09 seconds to the mark.
Then I ground the stop off the plate on the petcock so I could use the ON+RES mod position.
Petcock in new ON+RESposition, full tank of gas – 12.19 and backed that up with an 11.76.
Then I drilled the gas cap vent holes to 5/32” (2 on bottom and the nipple hole).
Petcock on ON+RES position, full tank of gas – 11.72 seconds to the mark.
Petcock on ON+RES, full tank of gas, No Gas Cap – 11.43 seconds to the mark.
I tried it again with a short hose and a piston shaped vent that is on my sons TTR90, and came up with around 13 seconds (I didn’t write it down).
So based on my results, I conclude that the ON+RES mod is a good one, but the pingel still flows much more. The drilled cap didn’t make much change but It would make more difference if you had a pingel and were flowing in the 6 second range.
