I wonder what this does to intake/exhaust timing; if full power would be
available in reverse. :->
Chuck
From: Chris Reinhardt <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: [F500] Rotax 493 installation
Date: Sat, 26 Aug 2006 10:29:01 -0700 (PDT)
The theory of operation is basically it spins the motor in the opposite
direction, and because you have two sets of pickups, the timing is correct
to run backwards. Not rocket science, but a cool feature.
CR
Jeff Blumenthal <[EMAIL PROTECTED]> wrote:
Bill,
You're asking the wrong guy for technical explanations. I can turn a
wrench but usually need someone to tell me which way.
All I can tell you is:
- the motor must be equipped from the factory with reverse. The main
ingredients that differentiate a reverse vs non-reverse is an extra set
of pickups and a different MPEM ignition module. You can identify a
motor that has reverse by looking at the wiring harnesses. All 493
motors have three wiring harnesses coming out of the motor. One has a
triangular connector, one has a round connector, and one is
rectangular. If the harness with the rectangular connector has 2 leads
it is NON-reverse. If it has 4 leads, it has reverse.( I believe that
the motors that Tony Murphy sells are equipped with reverse)
- I believe that sleds equipped with reverse have different clutches
but I'm told that regular clutches will work as long as you don't use
too much throttle in reverse mode.
- To activate reverse, you press a button which supplies a momentary
ground to the MPEM. To go forward, just press the button again.
-Jeff B.
Jan Schmidt wrote:
>Jeff,
>Can you give us a technical expaination as to how that reverse thingie
>actually works?
>Inquiring minds want to know.
>Bill Schmidt 88 red devil kawi (no reverse)
>
>
>
>>>>Jeff Blumenthal 08/26/06 9:51 AM >>>
>>>>
>>>>
>Sorry to interrupt the bike motor thread...
>
>I just finished installing a 493 in my KBS Mk8 and thought I'd share
>some info to save others the frustration I experienced.
>
>After completing the installation I tried to fire the engine. It
>cranked fine but did not even hint that it wanted to fire. I rechecked
>all my fittings, connections, etc. Spark was good and there was fuel in
>
>the carb bowls. I pulled the plugs and they were dry!? I pulled the
>fuel line off the carbs and cranked the engine to check fuel flow. There
>
>was plenty of fuel getting to the carbs. So everything checked fine but
>it wouldn't run.
>
>The 493 comes standard with a plastic "balance pipe" that connects the
>two carb manifolds. There is a hole (1/2") in each rubber manifold that
>the balance pipe connects to. When the 493 was first legalized, there
>was discussion about whether the balance pipe was legal...I can't recall
>
>what the current ruling is, but I don't use it because it does not fit
>my installation (because of the way I routed the cooling lines). I
>didn't have anything to plug the holes at the time and didn't think it
>would have any effect on starting the motor. WRONG!!! If those holes
>aren't plugged, or connected with the balance pipe, there is not enough
>suction to pull fuel from the carbs into the motor.
>
>I plugged the holes and the motor fired instantly.
>
>BTW, this is the first 493 I installed that has Rotax reverse. Very
>cool!!! Press the reverse button at idle and the motor almost comes to
>a stop, and then very quickly begins running the the reverse direction.
>
>The entire process only takes about one second to change direction.
>-Jeff B.
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