Pipo6007

Yes I put the standard lower back on myself and works perfect. Forward throttle and boat goes forward. Reverse throttle and boat goes in reverse. The new counter rotating was shipped from mercury warehouse in Atlanta with no prop but completely assembled with lower unit oil and all. I picked it up put my same counter prop that was on the old one.

I don’t doubt that happened. People make mistakes. Just making sure I wasn’t missing something here.

Not but my brother sent me a video of him putting the throttle in reverse and the boat was heading forward into our marina. This has never happened before so I’m guessing Mercury made the mistake since there hasn’t been any other valid explanation. I’m calling them tomorrow morning to see what the next step is.

prowlersfish

You replace a standard rotation unit with a counter rotation unit ? ??

Pipo6007

nope.

prowlersfish

Ok you said you put the standard one back on so I assumed you put a standard unit back on .

Pipo6007

I have twin engines. Standard is on the right (starboard) Counter is on the left (port).

Pipo6007

The rest of the paragraph explains what’s happening to the port. The standard engine is working fine.

noelm

I'm out, so confused with terminology and explanations about right hand props still going forward on counter rotation boxes.

Pipo6007

Okay, I have three or four engines and two are standard and one or two are counter. All of them spin one way or another. Trying to figure out which way they are spinning with reversing the props and shifting in different directions. Got it???

As basic as I can explain is the port motor (counter rotation) when engaged into forward gear makes the boat go in reverse.

westco

if it goes backwards when you put it in forward gear and frontwards when you put it in reverse with a lefthanded prop then it’s a right handed standard rotation lower

gfretwell

Tom gave you the answer. Flip the linkage in the controller. There should be directions in the manual of how to do that.

TTaxi

I have seen a maiden launch of a nice 30 ' boat with a pair of standard and counter O/B's pinned on the transom that went forward when the previously happy owner "reversed " from the Travellift well. But in that case it was a new installation , the lower units were correct for their sides but the mechanical control cables were pooched incorrectly to one engine. The cables were reconnected correctly before long and all was well.

But... your is not a new launch and the still-in-place motor in question should not have had any controls disconnected unless something was requested in that department . Your pic shows the correct prop if it was taken with the new L/U.
So in the likely event those Merc 300s' Fleet Master gear cases will not accept full power in both F & R , then yes , it sure sounds like the new L/U is labeled or built wrong and you need to swap it back out with a correct counter -rotation unit. I think most O/B will not take high thrust in R without severe damage, but can't hurt to check with your engine mfgr about that model. I think some Suzuki models may be rare exceptions as they reportedly can be configured either rotation with a switch or some-such non-mechanical easy change on the engine.

I expect Merc would mention 'full-reversing " re those l/u's if they could handle that , but they don't . So I wouldn't mess with the cables if they are still as they were previously. That could make things worse .
https://www.mercuryracing.com/outboa...-applications/
Your brother isn't by any chance a prankster , is he?

PF-88

I'm thinking the shifter gear shaft on the lower unit was not in the proper position when you installed the lower unit so when you put it in forward the lower unit selector shaft is putting it in reverse, this happened to me one time when I dropped the lower unit to change the water pump impeller, the gear selector shaft got moved so when I reinstalled the lower unit and shifted into forward the prop spun in reverse.

eman6501

Has he tried dropping the lower and making sure it didn't get bumped into gear when it was going back together? I know that Mercury recommends being in forward gear when reassembling, but I've done it in neutral plenty without issue. On the 90 I had last the shift shaft stayed up in the leg and coupled at the lower. Worth a try at least. Did he take the controls apart replacing a cable or anything or just the lower replacement?

30West

Is it possible your old unit was not reversed, they flipped the controls instead?

PF-88

Drop the lower unit, turn the input shaft by hand and check the rotation of the prop and gear shift selector shaft position, visually confirm the proper operation of gearshift control and that it matches the gearshift selector shaft and prop rotation, seems to me a pretty easy way to find out were the problem is.

Diesel Dawg

This would not be the first lower unit that Mercury built as a "standard" rotation but stamped as a "counter". If nothing else about your setup has changed and all you did was swap the lower units, then an improperly labeled lower unit is your cause.

Pipo6007

I spoke to mercury over the phone and they said to remove the lower unit and manually put it into forward gear. Then turn the main shaft clockwise. If the prop spins clockwise then they mislabeled the lower unit. Have the dealer ship it back to exchange it.

mystery

Will they pay the dealer to remove & return the wrong one and install the new one?

rdiesel01

This - I installed a new counter LU last year and the shift pattern on the newer LU's has been reversed. You need to reverse the shift pattern at your control box

Pipo6007

That sounds interesting. Is this something new? Was it an outboard? This new lower unit says it was built in December of 2019. Are yours mechanical controls?

I can call mercury tomorrow to see what they say about that.