T20 Airflow Problem
Posted: Sun Jun 20, 2021 8:11 am
Greetings, I just got my T20 running and am using a Kohler Air Filter (32 883 06 S1) recommended on the Facebook T20 scrambler forum site. The problem is I could not get the engine above 4500RPM in 4th, 5th or 6th gear. Ran like it was starving for gas/air. Tried my original filter (very old, stiff and discolored), slightly better performance but still hits a wall around 5000RPMs and surges a little when it gets there.
With the filter box removed (bare open carbs), it goes like a scalded dog, got it up to 80MPH, approx 7000RPMs with at least a 1000RPMs left. So I then ran it without any filter element installed in the air box just to make sure there is no obstruction in the box or rubber boots to the carbs. A very slight increase in performance but it still hits a wall at approx 5000RPMs in 4th, 5th or 6th gear just like when the element is installed. Just removed everything again and it performs very strongly.
LASTLY, I installed the air box bottom with a new filter and the top part totally remove, it ran wonderfully. I am suspecting an airflow problem thru the 1 1/4" opening into the filter box. Has anyone else experienced this problem. The boot is in great shape, no cracks or tears. What am I missing? Any thoughts on individual filters, using foam, wire screens etc. The bike is completely stock no modifications. Thanks for any help.
ettore
With the filter box removed (bare open carbs), it goes like a scalded dog, got it up to 80MPH, approx 7000RPMs with at least a 1000RPMs left. So I then ran it without any filter element installed in the air box just to make sure there is no obstruction in the box or rubber boots to the carbs. A very slight increase in performance but it still hits a wall at approx 5000RPMs in 4th, 5th or 6th gear just like when the element is installed. Just removed everything again and it performs very strongly.
LASTLY, I installed the air box bottom with a new filter and the top part totally remove, it ran wonderfully. I am suspecting an airflow problem thru the 1 1/4" opening into the filter box. Has anyone else experienced this problem. The boot is in great shape, no cracks or tears. What am I missing? Any thoughts on individual filters, using foam, wire screens etc. The bike is completely stock no modifications. Thanks for any help.
ettore