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rotation change

C'mon Folks, nobody wants to take a shot at this one? Ok, from looking at the manuals it looks like flopping the shift rod over to the other side of the slider will accomplish the change, what i'd like to find out is if it can be done at the control box, negating the need to pull the lower end. Both gears are straight cut bevel gears so it should be good to go just reversing the shift rod. Any thoughts?
 
I have counter rotation in BF225 and I was told that the bottom end would need to changed. Why would you want to do that?
 
Sorry folks but I still don't see a difference between a standard and a counter lower end, just the position of the shift rod, the gears look identical, and the manual doesn't address it at all, it just says to "position the flat in the direction of cruise" In fact, I saw a rebuilt on ebay with a notation to "flop the shift rod to the other side to make it a counter lower end" I'm confused, also a pretty fair mechanic
 
ok im right

on a counter rotater motor

the forward gear is on the back

on normal gear case it is on the front

do not switch just the shift shaft and prop, you will ruin the gear case
 
I don't specifically know the answer to your question but I can offer this:

I opened the parts blow ups from the two links below in separate windows and compared the right hand rotation transmission to the counter rotating assembly and there are some differences between the two that I would be concerned with. The part numbers don't cross between the forward and reverse gears, assembly to assembly, and the bearing placement for each is different. I don't think the change would be as simple as you state. Just my opinion.

http://www.boats.net/parts/search/H...99/PROPELLER SHAFT + PROPELLER (2)/parts.html

http://www.boats.net/parts/search/H...99/PROPELLER SHAFT + PROPELLER (1)/parts.html
 
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I can answer your question. The gearcases differ in the way load bearing bearings and gears are placed in the lower unit. In a standard rotation engine, the bearing and gear at the front of the gearcase (the part opposite of the prop, you know the bullet looking end) always have the forward gear. In a counter rotation gearcase the forward gear is always at the back. You cannot change the shift lever of a standard rotation gearcase to make it counter rotating, it will destroy the gearcase. You would be putting all of the load on the reverse gear and it's bearing, which are not designed for that use. Hondas counter rotation gearcases come apart the same way, unlike other brands of gearcases, however, the difference is in the bearing carrier which is different in the gearcases to handle different types of bearings.

I work at a marine engine and gearcase rebuilder. We supply shops all around the country. We build thousands of gearcases. I am also a certified Honda marine tech. Please do not try to change your standard rotation gearcase into a counter rotating gearcase by switching around cables or shift rods. It will destroy it.
 
Hondamech,

That was an exceptionally good, highly educational explanation. Thank you for that. Do I correctly assume that applies to all the larger Honda outboards?
 
Yes. All the large gearcases are the same. All counter rotational gearcases are constructed differently to a standard rotation gearcase
 
Nicely done fellas,
Although the manual is a little ambiguous the parts breakdown does tell the tale, the positions of the tapered roller and the*ball bearing are reversed on a counter lower end.* I'd be curious to see someone give it a try, but I don't have a couple thousand to spend on the experiment.* I guess I'll just be taking a beating on prop prices.* There is only one supplier for a 16" x 11"P x 3 LH prop that I can find and it's way pricey for an aluminun, would you believe $450.00 US?* Anyway,* Thank you all for your help, much appreciated,
*
Rich
 
It is never as simple as some people would like.---------------The standard lower unit " reverse bearing " set-up would not stand up to the loads generated being used as " full throttle forward "------------ Boat = Bring On Another Thousand ( $$$$ )
 
Check out these guys for a prop http://www.a1discountprop.com/a1index.html - don't know if they will have what you are after (if nothing is listed in their tables, give them a call) but I have used them extensively for motors I work on. Their prices are great (often 50-60% below retail) and you have it in a couple of days. They work out of a little office north of Detroit.

Aside from saving a few bucks on a prop (and having a bit better selection), a counter rotating motor will not perform any differently than a "normal rotation", in a single engine set up...
 
I have a similar issue in some ways...
Bought a pontoon boat with a 90hp 4 stroke BF90A BBBL-1008566 that a guy stated he had changed controls and rebuilt the foot. When I put in forwards, it goes in reverse and when I put in reverse, it goes forward. I opened the controls and they don't appear to be reversable. It doesn't appear that the lever under the engine cover can be changed. It has a right hand rotation prop on it - could this be a left hand rotation engine? Or, could the guy have put the gear in backwards during the rebuild? Is it possible to reassemble it backwards? Any way to tell? Maybe he should have put a LH rotation prop on? Any suggestions?
 
All of the 90A 's were right hand rotation. That vintage, though, actually had a Mercury gearcase on it. I am not sure if that year Mercury had a counterrotational gearcase for their 90's. in 1996. I know of no way to put it together backwards...although anything is possible.

Most likely, though, the shifter is probably your issue. I know you said that it appears that it can not be reversed.

Can you take a picture of it?

Even though they do not look like it, many still can be reversed.

Mike
 
Thanks - attached are some pictures. Mercury gearcase ... hmmm... maybe that explains the mercury branded prop. Also, the former owner mentioned he changed the controls. Attached are some pix. From looking at it, it appears that the cable can be moved to the bottom position.

Also, since he rebuilt the foot, is there anyway the vertical shifter can be installed wrong?

I understand that you say the gearcase gears can't be put in wrong.

Please let me know if the pix came thru. not sure how to add them...
Thanks Michael
 
This type of control is not made to reverse. It might be possible, but there is nothing in the rigging book for reversing these.

If you shift into forward, it should pull the cable forward. Likewise, if you shift into reverse, it should shift the motor into reverse.

The throttle should pull forward to advance the throttle on the engine. It is the one in the picture that is the outside one on the shifter.

This also looks like it is a right handed shifter. Which means, if you right hand is on the shift handle, your thumb should naturally go to the trim switch on the handle.

Your question on the Mercury prop...you can use a Mercury prop on the Honda 90's...even those with Honda gear cases. You just have to have the right thrust washer.

I do not know how the shift rod could be incorrectly installed. The Mercury gearcase has a shifter cam the attaches to the vertical shift rod going into the gearcase. I do not know if you can install these 180 degrees from normal operation and cause the gearcase to be "backwards".

I have not had to rebuild any of these...they usually coming in demolished and we just replace them with an updated gearcase. You might check with a Mercury mechanic. I would think Justintime would probably know.

Basically, if you push the shift lever on the engine forward and the engine goes backwards, then something is going on in the gear case.

Mike
 
Hi Guys,

When rebuilding the merc/honda gearcase the shift cam located on the end of the shift shaft labelled "THIS SIDE UP" must be placed facing DOWN or it will behave in the manner noted. Merc gearcases shift in the opposite rotation.
I have seen several people caught out with this :)
Cheers
John
 
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