Mercruiser 305 counterclockwise rotor

BUA

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Everything I read says the rotors turn clockwise... both of mine turn counter clockwise. Since my rotor turns counter clockwise am I right in assuming that the spark plug pattern I set up on my distributor cap is counterclockwise?
Thanks
 

Don S

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Re: Mercruiser 305 counterclockwise rotor

Everything I read says the rotors turn clockwise... both of mine turn counter clockwise. Since my rotor turns

Yes, they always turn clockwise. Even on counter rotating engines. You say BOTH of yours turn CCW. Assuming that means you have twins, did you by some chance switch starters?
 

BUA

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Re: Mercruiser 305 counterclockwise rotor

Yes, they always turn clockwise. Even on counter rotating engines. You say BOTH of yours turn CCW. Assuming that means you have twins, did you by some chance switch starters?

Yes I have twins. Starboard engine flywheel is clockwise, port is counter clockwise. The rotors both turn counter clockwise. I did have the starters out...didn't think it was possible to mix up which when to each engine.
 
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Bt Doctur

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Re: Mercruiser 305 counterclockwise rotor

block mounted or aft entry starters. If aft entry just swap the starters
 

BUA

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Re: Mercruiser 305 counterclockwise rotor

Yes I have twins. Starboard engine flywheel is clockwise, port is counter clockwise. The rotors both turn counter clockwise. I did have the starters out...didn't think it was possible to mix up which when to each engine.

Going to try to switch the starters...will let you know.
 

Don S

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Re: Mercruiser 305 counterclockwise rotor

Yes I have twins. Starboard engine flywheel is clockwise, port is counter clockwise. The rotors both turn counter clockwise. I did have the starters out...didn't think it was possible to mix up which when to each engine.

The engines turn opposite directions, which means the starters have to be different. The rotors ALWAYS turn clockwise. Doesn't matter if they are block or aft mounted.
 

BUA

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Re: Mercruiser 305 counterclockwise rotor

The engines turn opposite directions, which means the starters have to be different. The rotors ALWAYS turn clockwise. Doesn't matter if they are block or aft mounted.

OMG...a month and a half working on this...and you are 100% right (although engine not yet starting). I've read every forum possible trying to get to the bottom of my issues.
I switched the starters...the rotor is now turning clockwise. I set up the spark plug pattern on the dist to match. Tried to start and got sputtering and smoke. Guessing timing is off and might be flooded.
Thanks you so much Don.
I will keep you posted on progress.
 

BUA

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Re: Mercruiser 305 counterclockwise rotor

Some good news. Starboard engine started, runs great!!!
Port engine barking through the carb. I'm thinking it's flooding so I am going to clean and re-build it.
Thanks again for all the help.
 

Bt Doctur

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Re: Mercruiser 305 counterclockwise rotor

you do realize the firing order is different even though the rotors turn in the same direction.
order_zpsba78d965.jpg
 

Bt Doctur

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Re: Mercruiser 305 counterclockwise rotor

I know Don but with aft mounted ones the rotation is also reversed. You use a reverse rotation starter for a standard motor and a standard one for a reverse rotation motor.
 

BUA

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Re: Mercruiser 305 counterclockwise rotor

you do realize the firing order is different even though the rotors turn in the same direction.
order_zpsba78d965.jpg

Thanks...yes I have the firing order correct on the engine that won't start.
 
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