Starter motor spinning backwards ?

[Dirt ninja]

Long story short. I bought a used 2016 beta 300rr race. The P/O had the dealer remove the starter and related components before he took it home. I bought it with the starter bendix and related wiring in a bag among other bags of spare parts. I installed everything , huge pita to install the starter. Installed a battery and nothing but a click. Okay maybe the battery was old. Installed a lithium battery . Still click. Wtf ,take the starter out and take it apart. Again WTF one of the comm springs is missing . The spring turned up in a bag of parts. Put everything back together and I get the sweet sound of the starter motor turning but not turning the engine over. Rode the bike all summer and now it's raining daily so I'm tearing it apart and it seems the starter motor is turning backwards. WTBF ? I'm stumped and I really don't like tearing the starter out . Any idea why it would? With the flywheel off and facing the starter spur gear it turns counter clockwise. Which is the direction if I spin the bendix it doesn't spin out and engage. I bought this bike because of estart and it's really starting to piss me off.

[Hubert Carpet]

The centre barrel of the starter case is on the wrong way round.

It contains the magnets and these have polarity (North and South). It is always a good idea with motors to mark the case parts before taking them apart. The direction a DC motor spins depends on the direction the current flows in a magnetic field.

Google "Fleming's Left Hand Rule" for more details.

Check the recent thread about removing starter motors to lessen the PITA.

[Dirt ninja]

I'm fimilar with Fleming's law . I didn't notice a difference in the can. I really should have marked the can. I picked the brain of 4 beta shops and they all told me the bendix was the problem. Thanks for the advice. I pulled the starter motor last night and the end cap was rotated 180 degrees.tonight I'm going to put it all back together . The removal is a pita , but a really smart design putting something that weighs this much that low . Thanks.

[Dirt ninja]

Finally got the bike back together. Bob's your Uncle , I now have a working starter. Three times the charm. Thanks.

[Hubert Carpet]

Excellent news. Well done.