1972 Mercury 4 HP (40) 2 stroke running backwards (counter clockwise).

[MinnesotaWilly]

I have 4 1970's 2 stroke Mercs. My 4 HP is running counter clockwise. I realize there were some earlier left hand rotation Mercs, but nothing in the 70's that I can find. Has anyone heard of this? I realized this when I installed a new impeller and the vanes were curved the wrong way.

It makes sense that a 2 stroke could run in either direction, but would the ignition advance work in either direction? I think maybe the previous owner wound the recoil / pull rope the wrong way, so it pulls counter clockwise. This motor came to me on a boat that now has my 20 HP model 200 on it. The 4 HP has only been run in a tank and a few minutes in a harbor. These little single cylinder 4 HP's are pretty cool and very portable.

Any info / help would be appreciated. I'm new to the forum, but all the way back in 1973 I was running a Merc 20 HP on a Boston Whaler exactly like the 20 HP I have been restoring. This 4 HP has really had me puzzled!

 

[racerone]

I believe you have the only example made.----Or as you say a previous owner mas doing an experiment

 

[fitz73222]

My it was an original south of the equater motor, where nature runs counterclockwise

 

[timguy]

Ha, the advance....which is quite aggressive on 2 strokes, would become a retarding movement, this would have to be completely modified, also changed to activating carburator opening from the other direction. Helical gears in lower unit would loose effective durability, functioning with full power while turning backwards....would not last. Not to mention a different prop. Recoil starter dogs and the associated receiver would not work turning backwards....ridiculous to consider someone would do this.

 

[boscoe]

Early early Mercs did not have a gear shift mechanism. The motor would run in forward if rotated one way to start and run in reverse if rotated the other way to start.

 

[timguy]

Yes, advance and carb were self operated. Pretty neat stuff.