Honda Bf2 Water Coming out of Cowling

[Jettyman]

This is my first post. I just joined after reading the excellent info on the Honda Bf2 engines. I recently purchased an old used and abused BF2 that has an impeller. After lots of work - replacing the rusted clutch inner housing and clutch, drilling out and retapping rocker cover and cleaning the carb she’s running great. One issue I’m having now is when running in a barrel the water is coming out the bottom of the cowling. Anyone ever seen this before? Any known fixes? Thanks in advance and I’ve had a great time reading the forum - Dave from New Jersey

 

[VicS]

The gasket at the top of the leg ???? Not now available as a Honda part so if it is you will have to make your own


Steve66 will know the answer for sure if he comes this way,

 

[Jettyman]

I think you’re right as when I took it apart/ put it back together there was no gasket. I’ll try making one. What a weird design

 

[VicS]

I think you’re right as when I took it apart/ put it back together there was no gasket. I’ll try making one. What a weird design

Actually I've now found it listed on the official parts website so perhaps it is available after all .

 

[Jettyman]

Thanks I’m looking it up now - I still can’t figure out how the water is supposed to flow but obviously it’s pumping water. I tried taking the lower unit apart to take a look at the impeller and vertical shaft bushing but it’s stuck pretty good. I’ll put the gasket on and “hope” every is ok instead of breaking something taking it apart.

 

[Laysula]

Your not confusing things with the "tell tale "are you?

 

[Jettyman]

The water is coming out of the lower cowling and not just one area - for lack of a better way to describe it there’s a light “unorganized” spray (big drops) from the back area at idle which increases with revs.

 

[Jettyman]

*back area = underside of cowling

 

[VicS]

*back area = underside of cowling

I believe your engine should have a "water check hole" below the steering swivel



Are you seeing this good water flow or is the check hole partially blocked?

Is the water level in the barrel about right or is it too high?

 

[Jettyman]

I don’t see any water coming out of the check hole - I’ll check for blockage. I also may have too much water in the barrel. I’ll try again later and report back. Thank you very much

 

[steve66]

Hi....unbolt the powerhead from the leg. Clean both mating faces and apply a smear of silicone

 

[Jettyman]

Thanks I’ll give it a go now. Can’t find the gasket anywhere so hopefully the silicone works

 

[steve66]

It does work. Its not a critical gasket

 

[CliveF]

Have a look a the diagram Vic S put up. The water is just to cool the exhaust gas that comes into the center of the top of the leg.
The water is pumped up the pipe 4 through the support 5 and hits the baffle 9 that sprays the water everywhere to cool the gas.
The gas water mix heads down the leg and out. There is excess water which comes out of the tell tale as shown in Vics second diagram.
Any other leaks you are correct to sort

To get at the impeller you HAVE to take the prop and gear cover off.
There is a circlip on then end of the driveshaft that holds the pinion gear on. Once removed the gear case should free from the leg, which lets you get at the pump.
This end of the shaft is a smaller diameter than the shaft above the impeller which is why it has to come downwards.
Barmy design but it is what it is.

Good luck with resolving your issue..

regards Clive

 

[Jettyman]

I applied silicone but I think I’m missing parts. I got this motor as a total basket case and according to the model BZBF is even supposed to have an impeller here’s a vid - actual pics caused I can’t figure out how to post a video

 

[Jettyman]

Oops can’t post pics either

 

[CliveF]

there is an impeller/pump it sits in the bottom of the leg directly above the vent slots in the bottom of the leg to the rear of the propeller.
If you are getting water out all over the place at the top then it implies the pump is working.
Obviously no guarantee on that you will have to confirm it for yourself.

good luck.

Clive

 

[Jettyman]

I think I know the answer to this question but....it looks like most of the parts for the water pump are discontinued so I guess I only really have two options -Run it as is or remove the impeller so the water going all the way up the shaft doesn’t rust out the clutch/bearing again. Can you run these older versions without the impeller installed? I’ll continue looking for the parts to do it right

 

[CliveF]

I got an impeller for mine just before xmas £10 delivered. the old one was totally striped and looked like a thick rubber washer. all of the vanes were resting in the recess behind the inlet grille.

So i guess you can run them without, although personally I would not.

 

[Jettyman]

Thanks Clive I haven’t looked in the leg (still building up the courage). I have a feeling it’s missing parts. I still can’t figure out how/why all of the water isn’t being diverted to the check hole. I’ll keep messing with it. It’s actually a fun motor to work on.