Honda BF50 "kicking" in reverse

[DaveC426913]

Just took my SeaSaw in to the mechanic to get the gearshift/throttle tuned professionally and the gearbox checked.

When I shift into reverse, I have two options:
1. Shift gently, causing it to grind the gears
2. Shift not gently, causing it to rev and "buck". (The motor "jumps" with a *thunk* every two seconds or so.)
There is no third option.

I did my solemn duty as a Mac owner to try to fix it myself first, but I could not get the right tuning.

I found out several things from the mechanic, while my SeaSaw was still in the parking lot.

1. The motor is not bucking *on its mount* like I thought it was (and yes, the locking pin is in place). The bucking is actually it slipping out of gear in the lower gearbox. The prop is put under load, then slips, and the load is taken off. This causes the motor to buck repeatedly.

2. This is (according to him, at least) a common problem with Honda O/Bs in particular and Japanese O/Bs in general.

3. I feared it may be stripped and need repair after a summer of this, but he suggested that they can take a bit of this and it might still be OK. He'll know when he gets it apart.

So now I'm just waiting to hear if this will be a three-digit fix or a four-digit fix.

[NiceAft]

Please let us know the eventual solution. There are several owners of the same motor on this board; me included (2003 50 HP Honda four stroke).

[DaveC426913]

Heard back from shop.

Apparently there's a threaded retainer ring they need to take off before they can get at the lower section. It's seized and it broke their tool.
(I won't know more until I show up to examine it.)

So they can't do anything. I've either got to live with it, or replace the whole lower portion, at about $3500 (unless a salvage comes along).

[Rumdirty]

Ughh... As a fellow BF 50 owner all I can do is sympathize. Hope it all works out. Please do keep us in the loop.

[Jimmyt]

Interesting. I'd be curious to see a pic of what they're up against. Surprised they couldn't offer a better alternative.

[Tomfoolery]

Apparently there's a threaded retainer ring they need to take off before they can get at the lower section. It's seized and it broke their tool.
(I won't know more until I show up to examine it.)

I'm guessing it's that large ring around the prop shaft. No way I'd try to take that out, even on a fresh water boat.

Did you try adjusting the shift rod?

[NiceAft]

Is this shop an authorized Honda repair shop?

[Jimmyt]

I'm guessing it's that large ring around the prop shaft. No way I'd try to take that out, even on a fresh water boat.

The big toothy guy just onside the rear opening? I can imagine salt water could make that a real treat to get off. Looks like you'd need a special tool, lots of PB Blaster, maybe some heat, a 3/4 drive impact, a six pack, and all of the curse words you've ever heard. Not a great design. Maybe he can find one in a bone yard; if he can't find a shop that's up for it.



Also, he might want to check the replacement price...

https://www.hondapartsnation.com/oempar ... /gear-case

[DaveC426913]

Ugh. Never rains but it pours.

I picked the boat up after-hours. Only got as far as the busy, busy main road before discovering that the brakes won't release.

Spent a half hour dodging cars on foot before I could get it to move enough to get into a parking lot.

I think the brakes won't release because either:
- I used a 1 7/8" ball instead of a 2"
- the tow vehicle is a pickup, but it's so small and low the trailer is tilting toward the front. That means, when it starts away from a stop, the hydraulic can't release.

I'm calling around to see if anyone else has a bigger tow vehicle (or one of those raised hitches).

Crossing my fingers that the boat's still there when I go back for it.

[Tomfoolery]

I'm guessing it's that large ring around the prop shaft. No way I'd try to take that out, even on a fresh water boat.

The big toothy guy just onside the rear opening? I can imagine salt water could make that a real treat to get off. Looks like you'd need a special tool, lots of PB Blaster, maybe some heat, a 3/4 drive impact, a six pack, and all of the curse words you've ever heard. Not a great design. Maybe he can find one in a bone yard; if he can't find a shop that's up for it.



Also, he might want to check the replacement price...

https://www.hondapartsnation.com/oempar ... /gear-case

Yeah, that’s the guy. Holds the entire guts in there. I’m afraid to change the seals in case it’s so corroded I can’t them to seal to the case again. And there’s two of them in there, one facing each way. So I just change the gear oil every fall, and keep the leg out of the water when I’m not using it.

[opie]

whoanellie!!!!
There is a lock-tabbed washer holding that ring in. If you don't bend the tabs then you will break your tool or worse, crack the aluminum housing. I put a big discussion of this here many years ago. Forget all the work involved in searching for the thread and don't waste money trying to fix it. The aluminum threads will be spalled and you will never trust your engine on a long trip.
Here's what to do.
Order a new lower unit like I did.
Here is info....just confirm your exact model number with them first.

Babbitts Arctic Cat Partshouse

Aug 7, 2019

Details

Order Confirmation

Reference Number: 2054789

Via: Standard Ground

Est. Delivery:
8/14/2019 - 8/16/2019

CASE ASSY., GEAR *NH282MU* (L-TYPE) (OYSTER SILVER METALLIC-U)

Honda Item #41100-ZW4-H16ZA

Subtotal: $1,006.93 Shipping:$51.99 Salestax:$74.12
Total:$1,133.04

[DaveC426913]

OK, boat is back at the mechanic's.

We got it moving but it felt very heavy. Luckily, we only went 500 yards back to the mechanic.

We weren't sure whether it was actually seizing. So my friend checked. I quote him:

Well, this left bearing doesn't seem to be be warming up. I'd expect it to be warm if the brake was seized. I'll just check the right bearing here to see howYYYYEAAAAAGHHH@#$%*!(%#&^!#&$%*#$%#($ :pulls out blackened stumps of fingers:

So we're pretty sure the right bearing is seized.

All the hammer-and-WD-40 tricks in the book didn't release it.

[DaveC426913]

whoanellie!!!!
There is a lock-tabbed washer holding that ring in. If you don't bend the tabs then you will break your tool

Well, he broke his tool...

Yeah, he said I could pick up a new one for maybe $3500. But he'll keep an eye out for a used one.

Thing is, that isn't necessarily what I need. That's only if there's something wrong. If he just adjusts throttle cable, I might be all good.

[Jimmyt]

If you are going to pay $3,500 for replacement of an $1,100 part; you must have one heck of a lot of respect for that mechanic. Also, if he could fix it by adjusting the cable, why were you hauling the boat home? I thought your only option was a new foot or a bone yard piece. Maybe I missed something somewhere. I ain't the sharpest knife in the drawer.

Man, I hate you had brake/bearing issues. Hope you make it to the bottom of the hill soon so you can start looking up for a change!

[Jimmyt]

Yeah, that’s the guy. Holds the entire guts in there. I’m afraid to change the seals in case it’s so corroded I can’t them to seal to the case again. And there’s two of them in there, one facing each way. So I just change the gear oil every fall, and keep the leg out of the water when I’m not using it.

I get it. If it ain't broke, don't fix it. Unfortunately, I usually go by: if it ain't broke, I need to take it apart and see why not...