honda 2.3 O/B - prop not turning

SAWDOC

SAWDOC

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hi folks
Start of season: my honda o/b starts fine sounds ok and revs ok with the throttle handle. The prop wont turn even by hand. Any ideas how to solve?
 
If it won't turn by hand then its not the shear pin, because if that is broken it should turn by hand, but have no drive under power. Does it go into gear? If so does that stall the engine? If it does then it sounds like a siezed up gearbox or shaft bearing.
 
Norman_E said:
If it won't turn by hand then its not the shear pin, because if that is broken it should turn by hand, but have no drive under power. Does it go into gear? If so does that stall the engine? If it does then it sounds like a siezed up gearbox or shaft bearing.
Click to expand...

Agreed. My mistake.
Remember the BF2.3 doesn't have a normal gear box as such. It has a centrifugal clutch.

Schematics
http://www.hondaoriginalparts.com/pe/honda_outboard_parts_block_selection_M30.php?mod_01=30502
 
If it revs ok and it has a centrifugal clutch but the prop cannot be moved then assuming the centrifugal clutch is working and not badly slipping and the engine does not try to stall when revved then it sounds like something is broken in the gearbox. Did it stop suddenly when last used, did the prop hit the ground and stop the engine? I wonder if a tooth has broken off one of the bevel gears, jammed between the gears, and in the process sheared the vertical drive shaft. Shear pin should have been the weakest link if the prop struck something but you never know.

If the engine starts to struggle when being revved then the clutch is biting and can't turn the drive shaft so in that case may not be sheared, but the gears could still be mashed, or at least something has jammed/seized. I assume there is no impellor to break/jam if it is a forced air cooled engine.

Sounds like you may need to take the bottom of the leg off to investigate.
 
neilf39 said:
If it revs ok and it has a centrifugal clutch but the prop cannot be moved then assuming the centrifugal clutch is working and not badly slipping and the engine does not try to stall when revved then it sounds like something is broken in the gearbox.
Click to expand...

Clutch seems to be working grand she revs up as one would expect. the flow of air bubbles increases just above the prop but the prop itself does not turn. I have removed the prop checked all ok with shear pin, applied a little marine grease to what was exposed. Ran it again all sounds ok but no prop movement. tried turning the prop by hand with moderate force - just broke the shear pin. As stated above replacement available so have reassembled with second shear pin in place.
AFAIK no collision involving prop took place and any reluctance to move is down to 5 months in the shed after flushing with fresh water.
 
Clutch seems to be working grand
Click to expand...
I don't undersatnd how you deduce that the clutch is working

If you cannot turn the prop when the engine is not running something must either be siezed or or broken and jammed


If the clutch is working properly then it should engage when the engine revs are increased. If the transmission wont turn then the clutch will prevent the engine revs rising, acting like a brake.

:confused::confused:

Gear box oil is ok and was changed at the end of last season with no signs of signs of water ingress?

If so unlikely to be a problem with the gear box.

I reckon it might be the bearing that carries the outer part of the clutch assembly or the bush through which the drive shaft passes at the bottom of the leg.

Colhel was lucky .. a burst of engine power got it moving.
 
SAWDOC said:
Clutch seems to be working grand she revs up as one would expect. the flow of air bubbles increases just above the prop but the prop itself does not turn. I have removed the prop checked all ok with shear pin, applied a little marine grease to what was exposed. Ran it again all sounds ok but no prop movement. tried turning the prop by hand with moderate force - just broke the shear pin. As stated above replacement available so have reassembled with second shear pin in place.
AFAIK no collision involving prop took place and any reluctance to move is down to 5 months in the shed after flushing with fresh water.
Click to expand...
If the clutch "is working fine" but the prop will not turn, the engine cannot rev as the clutch will act as break. I say centrifugal clutch is siezed in unexpanded position jamming the transfer shaft.
 
VicS said:
I reckon it might be the bearing that carries the outer part of the clutch assembly or the bush through which the drive shaft passes at the bottom of the leg.

Colhel was lucky .. a burst of engine power got it moving.
Click to expand...

That's my theory, some old gunge or corrosion in a bush or bearing.
Mine is under 2 years old, The season before last it was mainly in freshwater, last season, salt water, stored in shed over Winter, if that helps your fault finding.
 
Update.
Tried revving a few times - no joy. My reason for saying the clutch seemed to be working ok is that when turned the revs did increase and the air bubbles in thew was also increased - the only missing ingredient was the prop turning.

Anyway, had to go off on an errand for an hour during which time I decided I was at nothing breaking shear pins so soon as I returned to base, removed prop again removed shear pin and inserted allen key through shear pin ope. I then attached vice grip to both sides of allen key and wiggled away. After a minute ot two thought I detected a slight movement and then hey presto she started to turn!
prop back on, stuck her back in the barrell and great! lovely churning water!
So similar problem as colhel described above, different solution. By the way, my o/b is now entering its sixth season and this never occured before.
Thanks one and all for suggestions and advice.
 
SAWDOC said:
Update.
Tried revving a few times - no joy. My reason for saying the clutch seemed to be working ok is that when turned the revs did increase and the air bubbles in thew was also increased - the only missing ingredient was the prop turning.

Anyway, had to go off on an errand for an hour during which time I decided I was at nothing breaking shear pins so soon as I returned to base, removed prop again removed shear pin and inserted allen key through shear pin ope. I then attached vice grip to both sides of allen key and wiggled away. After a minute ot two thought I detected a slight movement and then hey presto she started to turn!
prop back on, stuck her back in the barrell and great! lovely churning water!
So similar problem as colhel described above, different solution. By the way, my o/b is now entering its sixth season and this never occured before.
Thanks one and all for suggestions and advice.
Click to expand...



I have the same motor and I make a point of putting it in a dustbin of water and running it for 10mins once a month -simply to stop the sort of thing happening that you have just encountered
 
wizard said:
I have the same motor and I make a point of putting it in a dustbin of water and running it for 10mins once a month -simply to stop the sort of thing happening that you have just encountered
Click to expand...

I find putting it in a harbourful of water and running it 5mins each way to the mooring & back has the same effect. A bit more than once a month though.

I think I once had that lockup once, engine stalled at rev up and prop was stuck, but it freed by wiggling the prop.
 
Good outcome in the end.
But what can be done to prevent this from happening?
I got one sitting in my shed for all winter, so would like to add a small maintenance job for next fall to prevent this - if possible.
 
SAWDOC said:
After a minute ot two thought I detected a slight movement and then hey presto she started to turn!
.
Click to expand...
I would suggest you may not be out of the woods yet.
If corrosion caused that lock-up then it won't have been cured by getting it to turn. There is still something in there which has corrosion.
I'd certainly strip out the gearbox for a look.
 
Honda

Had the same problem: you will find that if you do not strip the unit down you will damage the shaft bearing!!

My Honda was not used for some time, it would not start and the the prop was seized to cut a long story short I removed the carb blew it out with compressed air all was well, however I could not turn the prop. Like you I thought about forcing it but decided against it and glad I did. The clutch is similar to a brake drum, when revved the weighted brake shoes upen out to make contact with the drum face, and turn the shaft this was also rusted which is why it started "snatching".

On the top of the shaft thre is a bearing which was seized solid two days with wd40 and eventually I got it moving. Lots of debris came out due to what I consider to be very poor seals top and bottom.

IMHO if this is not cleaned out and new grease put in you will have to replace the bearing very soon it could damage the shaft also if it gets hot.
 
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