Something else that concerns me is that the locking pin is at the front of the
engine, whilst the flywheel is at the rear. The 912's crankshaft is unusual (for
a four stroke) in that it is built up out of multiple forgings which are pressed
together (like a two stroke crank). This means that the whole crank will tend to
twist when resisting the force needed to undo and tighten the flywheel bolt. My
concern is that the crank may twist out of alignment.
This happend to me once when rebuilding an old Norton Model 50 (Motor Cycle)
engine that also used a pressed crank.......and as they say....once bitten twice
shy.
Chris Beath's suggestion of using an impact wrench may well work, but it will
entail severe axial loads on the crank that may also disrupt it's alignment.
I would suggest loading the engine into the back of the car and running it
round to the local garage (or tyre fitter) who will have pneumatic impact wrench
that can deliver all of the "shock" with none of the axial loads..........ususal
fee is a packet of cigarettes!
It would be good if we could get some official feed back from a Rotax dealer
........are you out there Nigel Beale?
Nigel (147)
Chris Beath wrote:
> John etc
>
> The Rotax agent in New Zealand said that he has broken a lock pin because of
> the amount of torque required (which meant he then had to strip the engine
> down) and strongly recommends instead to use a pneumatic impact wrench on
> the rear nut. I suppose the theory is that the short sharp jarring on the
> nut will provide the breakout force required without applying too much
> torque to the crankshaft.
>
> My replacement stator is still 3 weeks away so I'd be interested in feedback
> from anyone who tries this first!
>
> Chris
> -----Original Message-----
> From: JohnJMoran@aol.com <JohnJMoran@aol.com>
> Date: Monday, 31 May 1999 07:03
> Subject: Stator Mod - Note 2
>
> >The saga of the stator mod continues:
> >
> >The Locktite #222 ordered after examining the directions in the kit arrived
> >so I began the stator mod. The first question arose in locating the lock
> >screw properly. The directions say to rotate the flywheel until the number
> >impressed on it lines up with the opening in the surround; there are two
> >numbers on my flywheel and 3 openings in the surround. The proper
> alignment
> >was found with the 4 digit number in the upper stbd opening. The locking
> slot
> >is easily visible through the lock pin hole per the directions. The lock
> pin
> >will protrude about 3/4 inch when the crank is locked.
> >
> >In removing the bolt which secures the flywheel, an impressive torque is
> >required. I had to brace my foot against the engine mount to get sufficient
> >leverage using a 16 inch handle. Using full body weight on the handle was
> >not sufficient. The flywheel puller worked well, producing a loud bang
> when
> >the Locktite on the shaft released.
> >
> >As the crowning touch, the replacement stator supplied for my 912S seems to
> >be the wrong one. The pins on the end of the replacement unit's red wires
> are
> >1/8 inch circular connectors while the installed stator has small flat pins
> >which look identical to those used for the connectors which go to the
> >ignition switch. There is no part number on the replacement unit. The only
> >notable difference (other than the connectors) is that the replacement
> stator
> >has a black dot of paint at the 6 o'clock position.
> >
> >Others about to start the stator mod would do well to open the ignition
> >connector and compare connectors before removing the engine to verify that
> >the proper replacement stator is in hand. Probably should try to verify
> that
> >the proper flywheel puller is supplied also since this is another place
> where
> >things could go awry.
> >
> >In my opinion, it would be extremely difficult to change the stator without
> >removing the engine from the airframe in the Mk 1 Europa with standard
> engine
> >mount. So far, it seems that it will be possible to make the change
> without
> >removing the engine mount from the engine.
> >
> >John A044
> >
>
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