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(150hp) Need help deciding between counter and regular lower unit

C

ColinW

New member
Hello,
I’m on the hunt for a new lower unit for my 150hp.
I’ve narrowed it down to two units. Could you let me know which one you would choose?

#1 counter rotating with nice stainless prop. 500 hours. Nice guy who said it ran great before the powerhead failed. Exterior is clean. Some corrosion inside that can probably be cleaned up.

#2 regular rotating. 900 hours. Guy bought it as a twin motor package with the other motor being good and this lower unit had a cylinder failure due to the tech forgetting to add oil.
No corrosion. Exterior clean.

I like #1 because the seller is the original owner. The counter rotating is mildly unsettling for prop availability.

Thank you!
 
ColinW said:
Hello,
I’m on the hunt for a new lower unit for my 150hp.
I’ve narrowed it down to two units. Could you let me know which one you would choose?

#1 counter rotating with nice stainless prop. 500 hours. Nice guy who said it ran great before the powerhead failed. Exterior is clean. Some corrosion inside that can probably be cleaned up.

#2 regular rotating. 900 hours. Guy bought it as a twin motor package with the other motor being good and this lower unit had a cylinder failure due to the tech forgetting to add oil.
No corrosion. Exterior clean.

I like #1 because the seller is the original owner. The counter rotating is mildly unsettling for prop availability.

Thank you!
Click to expand...
ColinW, I have Twin 150's. Left engine normal rotation and the other counter rotating. Don't believe you can use a CR for a single engine.
Not sure why not! CR is altered inside the gear box, not just a different prop.
When you say Lower Unit are you meaning gear box and extension housing? Or are you getting entire engine and removing lower unit?

Paul
 
I got into a mess and straightening it out may play out well for you here. I rebuilt a lower for an '05 or '06 Honda 90. Everything went well, until it was discovered that the prop shaft was turning in reverse. After spending a LOT of time on this, and Honda tech proving useless because they couldn't locate the engine serial number in their database, I figured out what I had done wrong. It turned out to be a simple assembly mistake.

Check out the offset pin on the bottom of the shift shaft #9 here:

Honda Outboard 150HP OEM Parts Diagram for Water Pump + Vertical Shaft | Boats.net

Buy OEM Parts for Honda Outboard 150HP Water Pump + Vertical Shaft Diagram
www.boats.net www.boats.net

I had located it on the LH side of the prop shaft (as seen looking at it from behind the boat). This produced a LH lower unit.

The answer was to remove the shaft and re-instal so the off set pin was on the RH side of the prop shaft. The pin will fit easily on either side of the prop shaft. That's all it takes..... or I should say, that's all it took on that one. Back in business after a simple swap.

See if you can verify this somewhere, because I'd hate to be responsible for somebody wasting a lot of time and money on an issue like this. I'm just sharing what I ran into... -Al
 
Wow, so there really is not much of a difference between LH and RH lower units.

To clarify, my RH lower unit is bad and I’m shopping for a new one. I’m considering a LH lower unit. Both LH and RH use the same gear case and shaft but the gears inside are different or just the placement of the offset pin as Alan has stated.
According to my research, only the limited prop selection would be the downside of going with a LH lower unit as your main motor.
Any input is appreciated,
Colin
 
Colin the left vs. right seating position is often established by prop rotation. The blade going down (as viewed from the rear) provides lift on that side of the boat (rh prop = seating on right). That may or not play for your boat when switching. Just something else to consider.
 
No experience here...just want to point out difference...parts wise... of Right Rotation vs. Counter rotating.

Below Right rotating transmission:

Honda Outboard 150HP OEM Parts Diagram for Propeller Shaft + Propeller | Boats.net

Buy OEM Parts for Honda Outboard 150HP Propeller Shaft + Propeller Diagram
www.boats.net www.boats.net

Then below, counter rotation:

Honda Outboard 150HP OEM Parts Diagram for PROPELLER SHAFT + PROPELLER (COUNTER ROTATION) | Boats.net

Buy OEM Parts for Honda Outboard 150HP PROPELLER SHAFT + PROPELLER (COUNTER ROTATION) Diagram
www.boats.net www.boats.net

One thing that jumps out in the counter rotating unit is item 11,
Holder, bearing.
Also, of course, there are the reversed bevel gears between the two.

There might be other subtle differences I know nothing about or I'm not seeing but just putting it out there for you to look over.

Good luck.
 
They reverse the location of the 2 main prop shaft bearings too. The front bearing in the RH drive is tapered, the rear is a roller. The LH drive needs that bearing holder to set the pre load on a tapered bearing which is now at the rear of the case, with the roller bearing located forward.

All of which makes no sense here, but I never claimed to be an engineer either....

Bottom line, clearly there are big (insurmountable) difference in the 2 types......
 
Good points.
The leaning to one side and the location of the captain seat (starboard) may be a deal breaker for the LH lower unit as my boat is a pretty light (2800 lbs w/o motor and fuel) 22’ aluminum with a shallow deadrise (former inboard river boat—14-16 degree) so I can see it being prone to tipping one way or the other.
 
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