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MY21 650 SBA 146, ES, ICE Storm 1.5
6,618 Posts
Discussion Starter · #1 ·
Here is some information on the PERC-4, electrically controlled mechanical reverse chaincase.

To engage it you must press the yellow PERC button for about 1 second, with 0 MPH on the driveaxle and below 2500 RPM on the motor. An indicator light will go on when it is engaged. There is a 6000 RPM engine speed limit when in reverse.

If the engine stops running for any reason, after the restart it will be in forward gear automatically.

The gearcase is very sturdy, and all new. It has 8.42" center to center distance on the sprockets. It uses 3/4" HYVO 3/8" pitch chain like the EDGE and non-racing IQ.

Listed gear/chain combinations currently used are:

21/46-80 FS Classic, FS Touring
24/44-80 23/46-80 FST Touring
24/40/78 23/46-80 FST Classic, FST Switchback

The shaft ends the sprockets fit on are larger and have more splines. The top sprocket has 24 splines, the bottom sprocket has 31 splines.

Chaincase oil should be checked every 500 miles and changed every 1000 miles.
It will take 9 ounces, poured in throught the dipstick hole. There is a drain plug accessible form under the bellypan. It has a Tesnel plastic tensioner with a large rounded wear surface similar to the '06 2 stroke chaincase. A bolt gives tension, 1/4 turn back from finger tight, it is supposed to wear very well and not need much adjustment after break in.

The chaincase is tricky to put the cover back on when it is in the sled. You may need a hacksaw blade to guide the forks and gears into place.

The servo motor can be actuated with a 9 volt battery for testing purposes.
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