3.9 Mercury

[iggyw1]

I just picked up a 1964 Merc, 3.9 H.P. I do not know the model number, but I may be able to find it somewhere on the motor. It appears to be in great condition, and the previous owner ran it for me on his little boat on his lake. It starts up and runs fine. Has a gear shifter, neutral, reverse and forward. Went thru all the gears fine too. My question now:

I noticed when in forward the prop spun in only one direction, when in neutral, it spun in both directions, but in reverse, it does not spin in either direction. Is this normal on this motor to not spin in either direction while in reverse? The forward gear and neutral gear I can understand, but in reverse, it does not spin either way. When he ran it for me, it went into all the gears while it was on the water. Did not try it yet as I have no garbage can nor a motor cart of any kind, but just seemed strange that it won't spin in reverse.

 

[iggyw1]

I re-read my post and I was not too clear on it. I tried spinning the prop in gear but while the motor WAS NOT RUNNING.. I left that part out and thought it was important for all of you to know that.

I just ran the motor in a garbage can full of water, and it ran great. Forward, reverse & neutral all work great! But still, when the motor is off and in reverse, the prop still will not spin in either direction, neutral spins both ways (as it should) and forward only spins one direction (as it should). Just wondering if this is normal for this motor or should it only spin one direction when in reverse???

 

[iggyw1]

Does ANYONE have this motor out there that would check this out for me on their motor?? I would like to prevent any damage this may cause if it is not normal for the reverse gear to prevent the prop from free spinning in one direction like the forward gear does. Thanks!!

 

[River Boy]

Yep. That's normal for a 3.9 / 4.5 Merc.

 

[iggyw1]

Yep. That's normal for a 3.9 / 4.5 Merc.

Thank you very much River Boy. I was hoping that was the case.