OK to Use Left Handed Engine in Single Setup

[bent monkey]

I am getting a deal on a new Yamaha F250 but it is a left handed engine and I have an OX 66 Right Handed and wanted to know if I should stick with a right handed engine.
I realize backing down/docking will be different but other than that is there anything that I am missing or should think about?
Thanks
Sean

 

[DaleH]

Just turn the wheel the other way ...

Have heard of people doing this. Service & parts will differ, props could be pricey, if available in the config you're looking for, i.e., not all LH props are made in design/diam/pitch of typical RH availability.

Impeller/waterpump service should be identical as I believe the crankshaft turns the same way, with the delta being at the dog gears.

 

[bent monkey]

I am just wondering if it would be possible to change the gear out in the lower unit to make it a right hand, I already have a great tuned RH prop. I am on hold with Yamaha US HQ right now.

 

[bent monkey]

I spoke to Yamaha and Parker and the only difference is that the Yamaha guy said that I will lose about 200 RPM's or so, but he also said that he would go with a LEFT Hand Engine as the gears are stronger than the standard Right Hand engine.
He asked me to call Parker to ensure they didn't build 'wedge' into the boat for a RH engine and they said that they do not.
So there you have it, you lose some RPM's but the trade off is a much stronger gear case.

 

[B-Faithful]

hmm 200 rpm loss for the counter rotation... :?: How does that work when syncronizing twins :?:

 

[bent monkey]

hmm 200 rpm loss for the counter rotation... :?: How does that work when syncronizing twins :?:

I am not sure about that, I have a single. The unit I am buying is an F250 that they are giving me for 14k with the 5 year warranty so I think I can live with 200 less RPM's at WOT.......

 

[DaleH]

... the Yamaha guy said that I will lose about 200 RPM's or so, but he also said that he would go with a LEFT Hand Engine as the gears are stronger than the standard Right Hand engine.

Now that makes NO sense, what a lame comment as phrased. That would imply on a RH motor that reverse gears are stronger than forward gears! Whereas the positioning of the Fwd/Rvs gears to the propshaft must be opposite, since they are essentially have to be reversed from a RH motor because the crankshaft still spins the same way.

Anyway, just BUY it and use it. I'd also bet $$ you won't see any RPM loss.

 

[bent monkey]

... the Yamaha guy said that I will lose about 200 RPM's or so, but he also said that he would go with a LEFT Hand Engine as the gears are stronger than the standard Right Hand engine.

Now that makes NO sense, what a lame comment as phrased. Whereas the positioning of the Fwd/Rvs gears to the propshaft, since they are essentially reversed from a RH motor because the crankshaft still spins the same way.

Anyway, BUY it and use it. I'd also bet $$ you won't see any RPM loss.

I thought twice about his statement as well but those words came from his mouth, anyway, I am moving forward with it.
Just have to get used to the difference when backing down.
Oh, one more thought, would the ducer for the sounder need to be moved from starboard to port due to the different rotation?

 

[John_Madison CT]

I have a left-hand rotation outboard on my 2520DV single screw. Absolutely no difference from a right hand turn outboard.

I bought a spare prop on Ebay cheap as nobody bid on it.

I get 5300RPM's out of a 17" pitch Mercury Mirage prop on my 250hp Yamaha Ox66.

 

[Megabyte]

I have a neighbor who repowered his Proline CC with a LH OX66 and he has had absolutely no issues with it.
It is a great way to repower and save a few bucks in the process. :wink:

 

[bent monkey]

Thanks for the feedback guys, You have no idea how much I appreciate it! You know that feeling when you are about to spend a lot of money and are not quite sure it is for the right thing, well multiply that times 100!
I am baffled at the Yamaha Rep's feedback, posted above, that is what threw me for a loop and started me worrying :shock:
Can't wait to see how this big 250 scoots my 2310 along

 

[bent monkey]

Done Deal! Took it out yesterday and still have to get the right prop, put a 19 on there and could only get up to 5100 or so, but have a 17 to try today.
I'll read that sticky in the forum but if anyone has any more specific feedback on props I would love to hear it.
Thanks Again!
Sean

 

[bent monkey]

Congratulations

"2310" ?

Looks like a candidate for Merc Rev 4 17p and raise up motor a couple of holes.

Yeah, 2310. you think that prop would do it and why raise the engine?

 

[Megabyte]

The Rev 4 is a 4-blade prop.
4-blade props generally perform better with the motor moved-up a bit.

 

[bent monkey]

The Rev 4 is a 4-blade prop.
4-blade props generally perform better with the motor moved-up a bit.

OK, got it. I am really ignorant about props, really ignorant.

 

[bent monkey]

Lower units have tremendous drag. Whole purpose of Merc Rev 4 is to bite better allowing you to raise up LU.

In my 23DVCC (same hull as yours), motor higest position, less time to plane, less bow rise, planes @ lower RPM, backs better, 2.5-3.5 mpg (all ocean runnin'), actually runs a little faster w/motor now raised up, less wake.

A side benefit of Rev 4 is yer get rid of sometimes problematic rubber doughnut in prop.

that sounds like a great option, which motor do you have?

 

[bent monkey]

Today I tested a Mirage Plus 15 3/8 x 18. All I can say is this thing seems to be perfectly tuned to the 2320/f250. The engine sings like a turbine in the midrange as well as at cruise (4500rpm). The Mirage 15.25 x 19 would make the engine work a little harder than I liked as it ran a little louder and not quite as smooth.

Today's test:

100 gal fuel
2.5 people
200 lbs gear/ice/food

Conditions 5 knts on the nose, seas 1 ft tight chop.

25 mph 3700 rpm 3.1 mpg
30 mph 4100 rpm 3.0 mpg
35 mph 4600 rpm 2.7-2.8 fluctuating

WOT 46 mph 5900 easy - 6000 briefly

The best 3 blade prop I've tested. Engine sounds great with this prop. I'm done testing---out.

The above from grouperjim in the prop sticky sounds like my setup as well so I will try a 4 and the one he uses and see what happens.

 

[bent monkey]

Do NOT try the Rev 4 unless you raise up motor at least 2 positions off bottom holes. It's easy to raise motor if you have a trailer. One man 30 minute job.

Roger.

 

[bent monkey]

I spoke to Yamaha and Parker and the only difference is that the Yamaha guy said that I will lose about 200 RPM's or so, but he also said that he would go with a LEFT Hand Engine as the gears are stronger than the standard Right Hand engine.
.
So there you have it, you lose some RPM's but the trade off is a much stronger gear case.

Looks like Yamaha rep was exactly right. Took me a while to find this.

June issue, page 75. Off Road Adventures................

"A hypoid axle with a reverse cut ring gear (right in photo). Mounted in the axle, the pinion is above the axle centerline rather than below it. When used in a front axle, a reverse cut ring and pinion is about 15 percent stronger than a standard ring and pinion. If a high pinion is used in back, the reverse is true."

btw, how's the new power? 8)

NO SH*T!! Really? Well that is news to me.
I will have to do so Google'ing on the subject now to find out more. If nothing else the gear case is stronger like he said and he did say that if he had a choice he would go with the LH, so makes me feel better. I wonder if what he said about the 'lose 200 RPM's vs. a RH' is true.

New engine is great, just trying to prop it right now, going to try a Mirage 18 and see what happens.
Thanks for the tenacity and discovering this info.

 

[bent monkey]

Here are a number of Google results showing that the reverse gear is stronger:
http://www.google.com/search?hl=en&q=A+ ... 5&ie=UTF-8