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Honda bf9.9/15a lower unit

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Farmer fuller

New member
I currently have a major problem with my lower unit I currently only have forward gear I have messed around with the link rods. I can not find neutral all reverse what ever way I adjusted them I then decided to take Lower unit to bits and found that the dog clutch is not reaching reverse when the sprung loaded pin is pushed in it seems like the pin has warn out. Is this normal seems poor design as the pin just runs on two step wedge from gear linkage and wears it out.
am I missing a piece.
And can I use a different lower unit off a mucurey as I have read that they used them up to 1999 and what Lower units can I use off other Honda say bf8. Also what do people mean about a two piece drive shaft I only have ever worked on this one engine as it is my first one I have owned the lower unit has the crooked link rod if helps.
 
Hi,
I'll give it a try. First off, the Merc lower ends on some Honda outboards were actually considered "inferior" and many owners were pleased when Honda came out with their own. So, I would not recommend anything like that as a solution. I believe the Merc gear cases were only utilized on the larger Hondas anyway.

I've worked on MANY of the 2002 and newer twin Honda gear boxes and I have NEVER seen the shift pin wear out. Although, I guess it's possible.

Most "gear selection" problems are solved viz the proper adjustment of the shift rod.

Have you:

attempted to adjust the shift rod while the transmission is in reverse?
Threaded the shift rod connector nut 3/16" to 1/4" on to the lower rod?
verified that the shift rods are not unduly bent or are hanging up in some way?

Sorry I don't have a pin to measure to give you some specs but if you think your pin is worn, you can get one for about 5 bucks. See the link below to and it should help you determine if anything is missing.

I HAVE seen the clutch dogs wear out and it is useless trying to "file them square". If the ears are rounded, then it is best just to get new. They usually wear out because the skipper shifts from neutral into gear too SLOWLY. This causes the clutch to "chatter" and rounds off the ears. It is a good practice to shift the outboard into gear with a SHARP, CRISP MOVEMENT of the shift lever. The outboard should pretty much "bang" into gear if you want the clutch to live a long life.

http://www.boats.net/parts/search/Honda/Outboard Engine/1998/BF9.9AW LAS/PROPELLER SHAFT/parts.html

I hope this might help you but, if not, keep posting and I'm sure someone here will jump in with some wise counsel.
 
Thanks man you are a lot of help that diagram is spot on. I have looked more closer at dog clutch and reverse crown cog they are slightly warn from granny shifting. I am currently sourcing second hand lower unit as there is not the outlets like you have over there as I am from the U.K. What should I look for when purchasing new unit how much lateral play etc.
This is my first post on any forum and it's been fantastic experience many thanks
 
Hi Farmer fuller,
Thanks for the kind words even though I'm not sure how much I'll be able to sort this one out. I don't have any "engineering data" for the outboard. I don't know the year of yours so that parts page was just a guess. And, if it is an "overseas" (not sold in America) model, some or most of what I do have might not even apply. I just don't know.

I do know that the boats.net parts website offers international shipping. There is an "international" button on the home
page that provides clear shipping charges information. It seems that the charges for Australia and the UK are the same. It comes down to the size of your order. If you order up to about $300 (USD) the shipping is around 50 bucks USD. Not cheap but not outrageous to get your rig back up and running and FISHING again! The secret, of course, is find EVERYTHING you need and THINK you are GOING to NEED and order it all at once and be done with the shipping charges. I mean NGK plugs if you can't get them local...a carb kit..just in case, a water pump kit or at the least an impeller with gaskets...a new thermostat...these don't do well on a stuck stat....plus your gearcase pieces and anything else you might think of.

No, I don't have stock or any relation to boats.net. I'm just trying to give you a way to go if you strike out of the used part market wherever you are. I wish you luck with the search.
 
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