Could this boat have been re-powered with the wrong rotation motor???

v12mac

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Could this boat have been re-powered with the wrong rotation motor???<br /><br />This is an odd one..<br />My brother just purchased a Mako 23’ with a brand new Volvo crate motor 0 hours the owner had not even taken it out for a test run due to a medical condition. When we ran it today it felt like the transmission was slipping under load. 3-4k RPM.<br /><br />Now, this is the weird part. I have been running direct drive inboard ski boats all my life. When you put them in to reverse you get a wherrring sound that is very distinct to the straight inboard. This boat makes that sound in forward and no wherrr in reverse.<br /><br />Question: Could the mechanic that re-powered this boat have messed up and ordered a reverse rotation motor, installed it and to cover up the error changed the controls and swapped props to cover up the mistake? Or is there something I am missing here? What causes that distinct reverse sound in an inboard? Why would this rig make that noise in forward but not reverse?<br /><br />Any ideas would be welcome.<br /><br />Mac
 

baja power

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Re: Could this boat have been re-powered with the wrong rotation motor???

While looking at the motor from head on... It if it like most single. engine boats... The belts will turn to the right ( looking toward the transom) if it doesnt, Its a counter rotating motor..
 

Don S

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Re: Could this boat have been re-powered with the wrong rotation motor???

Volvo doesn't put out a counter rotating engine, so that eliminates that possibility. What model of engine and transmission are we talking about here.<br /><br />
Engine%20Rotation.png
 

v12mac

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Re: Could this boat have been re-powered with the wrong rotation motor???

The motor has a tag on it that says 5.0 the guy that sold my brother the boat said it had a 350 in it before and he repowerd with this motor. I'll get the model numbers.<br /><br />Mac
 

Don S

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Re: Could this boat have been re-powered with the wrong rotation motor???

OK, it's a Chevy V8, thats all that's need there. I assume it's a NEW motor, not a rebuild.<br />Really need to know what transmission you have and which direction the propshaft is turning when in forward gear.
 

v12mac

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Re: Could this boat have been re-powered with the wrong rotation motor???

Engine is Volvo Penta 3869162 5.0 G1-B ssn 4012067908<br />Trans is by Mercury Marine 5612458<br /><br />On closer inspection the motor is rotating to the left as pictured above but when in forward (Shift lever) the prop is rotating to the right, opposite to the fly wheel and sounding like every inboard boat I have ever run in reverse. <br /><br />Now looking at the linkage when you shift into forward the lever on the transmission moves toward the stern of the boat. <br /><br />Do I have the wrong engine, trans, prop or a combo??<br /><br />Ideas??<br /><br />Mac
 

Don S

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Re: Could this boat have been re-powered with the wrong rotation motor???

It's hard to say where the problem is. Your tranny number doesn't show up in the parts book, don't even mention a year, or even it's a V-drive or anything. Who knows if the prop was changed, perhaps the old engine was a counter rotating engine and when the new engine was installed they just changed the linkage.<br />You could probably just change props to one that rotates the same way as the engine, then change the linkage on the transmission and the thrust from the prop would be pushing the proper way on the bearings and gears inside the tranny/v-drive. Going the wrong way, the tranny will not last long.
 

muc

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Re: Could this boat have been re-powered with the wrong rotation motor???

I ran the serial number and this is not a "crate" motor it was put into service 11/02 in a 2003 Larson with a I/O Might want to check into whats going on. Like Don S. says if you run most trannys in reverse at high speeds for very long they don't like it.
 

Capt Ken

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Re: Could this boat have been re-powered with the wrong rotation motor???

Well, we do know the pump on the transmission is set correctly or the transmissin wouldn't be working at all. If the Mako is an older one, then more than likely the transmission is a Borg Warner. I would be real easy to tell if its running in reverse, just look on the transmission housing next to the shift lever, there's a F and a R. Its not uncommon for the Mako's to be running a 1.91:1 ratio which would make the prop turn opposite the engine.
 

v12mac

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Re: Could this boat have been re-powered with the wrong rotation motor???

Thanks for all the posts, I think we got this one solved.<br /><br />When the boat was in “Forward” kept hearing the whirr of a direct drive inboard in reverse, when we tried to plane the boat off the tyranny would slip. <br /><br />What happened: Looks like the wrench that dropped in the motor hooked up the linkage wrong and to cover up the mistake, he swapped the prop for a right hand rotation prop.<br /><br />We changed the linkage up on the Morse control, and put a left hand rotation prop on and wolaha! Problem solved. It is running great and super quite in forward with the standard whirr in reverse. Just need to dial in the prop size a bit.<br /><br />I’d like to dig in to the history of this motor a bit more if possible. How did you pull up that info? Is there a chance Volvo took this block and rebuilt it? <br /><br />Mac
 
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