Advantages /Disadvantages of a single counter rotating engine

[rocklobster]

Hello all ,
Just wondering about the goods and bads of a single engine with a counter rotating prop ,(left turning) would you own one ,if not why not . I myself cannot see any real disadvantage apart from the wider availability selection of propellors and a little more expense in their purshase. I have been told that counter rotating engine gearboxes are some what strong than their counterparts. Is their any truth in this .
Thanks in advance for your opinions

[Spaniard_King]

Cable steering will be harder than normal.. if you have hydraulic then the difference is hard to pick.

Gearboxes.. well there all built prety well these days I don't think there is a lot of difference strength wise. The counter rotator was brought out for twin engine setup and is normnally found in the larger HP brackets hence made to take some punishment.

As far as props go.. look in the USA.. a left hander is hard to sell second hand so IMO they tend to be cheaper :)

[fisho64]

Cable steering will be harder than normal.. i)


Just out of curiousity-why?

[cormorant]

Just out of curiousity-why?

A lot of counter R come with a straight or non existant trim tab as they are usually in matched pairs linked so it doesn't matter..

You can find CR trim tabs( not that a lot of people bother) - most people never set em up right from the get go.


Other problems are that if tranducer is mounted on the incorrect side it will be "airated" possibly and that replacement gearbox if required are 30% more expensive and fewer spares at wreckers.

Hell of a lot of CR are used in commercial boats so if buying 2nd hand you really want to know where it came from and check it out.

[Spaniard_King]

Just out of curiousity-why?

see above :)

[finga]

As an advantage...they'd be a lot cheaper second-hand.
But usually because of the reasons mentioned above.
Would they be cheap enough to get over the normal clockwise rotating?? I don't reckon so.

[rocklobster]

I have an option to buy one and i cant really see any issues apart from the resale . Many pairs are sold off cats and are sold separately ,the right always goes first and the left seem to sell cheaper . I was concerned as to any negative effects it may have the on hull with relation to performance.

[Jaguar 18]

I have a CR on my 6.1 Hydrofield (single mid mounted motor not twins) and have not had any issues its been great so far (three years) it came of a commercial ab boat.
As far as price I had a 90 hp merc which I put on ebay and sold for $4800 and pickup up a 200hp Merc 2003/4 model for $4500, at the time I added hydraulic steering and fitting I think the change over only cost 2K extra fitted.

[cormorant]

Pricing is quite funny

I know there is no CR boxes ( not whole motors) at the wreckers normally and when someone wants one they need to take the lube and bend over. New ones are overpriced and there is fewer rebuilt ones so they know they have you over the barrel.

I know people who have bought a good SR box and sold the CR box and had some cash in the pocket.

Some brands CR boxes don't seem to fail in lower HP but in higher HP have had issues. On cats they are used on close in manovouring so if you buy a ex waterways boat etc that has spent it's life inspecting boats on moorings in and out of gear you really need to know hours on the gearbox not just the motor as they chew out dog clutches and the metal goes through the box the rest of the time.

Coming from cats somemotors may have been well misted all the time which is a worry with 2 strokes as the water gets to the crank bearings etc.

Again - prop choice - be prepared to bend and get lubed up.

You can still tell is was originally a CR from the serial numbers on the motor.

[ifishcq1]

I have a 225 Honda CR and it gets lots of use
done over 600hrs and no issues at all

cheers

[Wet Work]

There is no real difference. props are harder to find but US ebay has heaps and they will be a lot cheaper, including shipping than what you will pay here. I have bought pairs of props in from states, sold the RH and that has paid most of the cost of the pair so i have ended up with a really cheap prop.

You just need to set the little trim tab up correctly for single LH use. Just the same as you would for RH motor use if it was one of a pair.

You can usually get the LH/CR motors cheaper than the rh ones. I certainly havent hesitated to get LH motors in past and i will be happy to buy them in the future.