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Honda B100 revival progress so far

DJ530

New member
Thought I would share a few progress pics of this project so far. What was supposed to be "Just needs a kill switch, and she will fire right up" has morphed into a semi-restoration lol Picked this one up for $380 bucks, said it just needed a kill switch. So far I am into a new kill switch, CDI box, new thermostat, intake gaskets, carb gasket, new impeller, housing, gaskets, a carb overhaul, and sorting out the wiring mess- well she is a great runner now. Few minor issues to sort out, the oil light won't light up for some reason, tested the sensor, wires, and the bulb, but no light, I know it has pressure so not sweating it for now. Also found a small leak at the exhaust gasket where it bolts to the head, seems to leak less and less the more I run it, but I may need to pull the head to swap out another gasket. So far real happy with the progress, thought I would have it on the water by now, but it has thrown me every challenge I can think of so far.

Fires on the first pull now, needed to tweak the choke rod to pull the choke completely shut, otherwise it was finicky on cold starts.
WP_20210905_09_40_25_Pro.jpg

My small leak, figures the one gasket I decided to reuse too.
WP_20210905_09_26_22_Pro.jpg

The new lower unit parts, went together smooth. I put a dab of grease on the drive shaft, and guided the water tube into the housing. When I pulled this apart, the water tube was just chilling out - outside of the pump housing, so that explains why it wasn't cooling. and the thermostat was on it's last leg after 40+ years.
WP_20210904_10_58_08_Pro.jpg

Pic of it idling, runs like a top. It seems to idle smoothest with the pilot screw about 1 1/4 turn from stop, otherwise the idle would surge at times when it warms up.

WP_20210905_09_26_33_Pro.jpg

Not sure if I should run it on the water with that exhaust gasket leaking water, it never overcomes the weep hole in the housing, and I really don't want to take the head off if I can avoid it this summer. Hope to do a water test tomorrow, we shall see.

Thanks to jgmo for all the help on this one! If it weren't for this board, not sure I would have been able to conquer this beast!
 
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Hi,
Seems like it's kept you pretty busy! It looks great btw!
These tough old gals can turn into a labor of love because they just seem to have so much character.

I don't know but one issue that you may run into with that leaking exhaust gasket is that, if too much exhaust gas accumulates in the compartment, the engine will be starved for oxygen and it will stall out on you.

It's a common problem with these outboards when that gasket fails. In which case, you can limp home by simply removing the hood and running it that way.

Pulling the power head to replace the gasket isn't too bad of a job and it can be an opportunity to swab out the oil sump and oil filter.

You've done some nice work there and I hope she serves you well for as long as you own her.
 
Hi,
Seems like it's kept you pretty busy! It looks great btw!
These tough old gals can turn into a labor of love because they just seem to have so much character.

I don't know but one issue that you may run into with that leaking exhaust gasket is that, if too much exhaust gas accumulates in the compartment, the engine will be starved for oxygen and it will stall out on you.

It's a common problem with these outboards when that gasket fails. In which case, you can limp home by simply removing the hood and running it that way.

Pulling the power head to replace the gasket isn't too bad of a job and it can be an opportunity to swab out the oil sump and oil filter.

You've done some nice work there and I hope she serves you well for as long as you own her.

Thanks! I think she will be a reliable unit. Ran into another issue with my trailer so didn't get it on the water today.

Is there a trick to getting to the captured bolt retaining the powerhead off? Is it accessible by pulling the extension housing off? When I looked, it seems I need to pull the head just to get it as it's buried behind the exhaust. I have a feeling the exhaust bolts weren't torqued since there was no corrosion when I had the intake off. Will order the gasket in case it keeps leaking, I have a little time to repair some brackets on the trailer.
 
Great work. Subscribed to your thread and will look at other posts as soon as I can figure out how. :p Love these old Hondas. I have 1 B100 and a B75. Nursing them both back to life so thanks for sharing. Peace.
 
Captured bolt? There is only a "concealed" or hidden bolt as far as I know. You do have to remove the extension case to access any of the bolts.

And, in reality, the concealed bolt isn't even really concealed in the true sense of the word. It's just harder to see than the other 7 bolts that hold the powerhead to the oil case.

5 bolts positioned toward the front of the case with 4 of them abreast of each other and and the 5th in just ahead of them

Then, 3 bolts abreast of each other toward the rear of the case with the concealed bolt being the middle one of the 3.

The secret to NOT SCREWING THIS UP is to never force anything. Once ALL 8 bolts are removed the powerhead will separate from the case with ease..

Keep track of the bolt placement. There are 6 bolts that are 32mm long and 2 bolts that are 45 mm long.
 
Captured bolt? There is only a "concealed" or hidden bolt as far as I know.

Yes the concealed bolt. I used the wrong term. Ok got it! I also stumbled upon this video showing where they all are: https://www.youtube.com/watch?v=7Zy7OpCxnaA so it looks pretty simple. Wondering if I can get a wobble socket up on the exhaust bolts to tighten it up once I remove the plate, as I think it is just loose. If I am going to pull the powerhead I might as well replace all the seals/gaskets I can since most are still available. By the time I am 'done' with this lump every seal and gasket in it will be new lol After seeing a few other older Honda's and how bad of shape they can get (salt water corrosion), this one is in mint condition aside from a few cosmetic blunders, the previous owner decided to rattle can the whole motor, black on the bottom extension/gear case, and silver spray paint on the cowling, so it's not the prettiest setup but it sure runs good now. If I get time I will refinish the cowling cover to make it really pop.
 
I'm not sure about getting a wobble socket on all three bolts but, shucks, it might certainly be worth a try.

You are correct about doing what you can to minimize having to "go back in" if you're forced to take the powerhead out. The parts that are still available might not be for much longer as Honda will undoubtedly end all support at some point.

With that in mind, look the exhaust pipe over very carefully for any galvanic corrosion or damage. It is still being sold and if it needs replacement, now is the time. Item 16 in the link below. Pay particular attention to the inside of the water channel because that's where the pipe will corrode the most.

https://www.boats.net/catalog/honda...bf100-sa-pre-1997/oil-pump-oil-filter-muffler

While you may not like the paint job, yours looks pretty clean where it really counts.....under the hood!...;>)
 
Great work. Subscribed to your thread and will look at other posts as soon as I can figure out how. :p Love these old Hondas. I have 1 B100 and a B75. Nursing them both back to life so thanks for sharing. Peace.

Thanks! Since we already own a couple of Honda bikes it was a natural fit into my fleet. So far really liking it now that I have all it's issues worked out - it was one of those iffy purchases to begin, for a while I thought I bought a POS since it was a mystery buy.

For anyone else following along, here is some live action footage of her running, hope it's ok to post links yet.
https://www.youtube.com/watch?v=7RE8CpPjJ-8
 
I'm not sure about getting a wobble socket on all three bolts but, shucks, it might certainly be worth a try.

You are correct about doing what you can to minimize having to "go back in" if you're forced to take the powerhead out. The parts that are still available might not be for much longer as Honda will undoubtedly end all support at some point.

With that in mind, look the exhaust pipe over very carefully for any galvanic corrosion or damage. It is still being sold and if it needs replacement, now is the time. Item 16 in the link below. Pay particular attention to the inside of the water channel because that's where the pipe will corrode the most.

https://www.boats.net/catalog/honda...bf100-sa-pre-1997/oil-pump-oil-filter-muffler

While you may not like the paint job, yours looks pretty clean where it really counts.....under the hood!...;>)

Thanks! Ok I will look it over close, from what I saw so far there is really no corrosion anywhere on this motor, just some dirt mostly and the crap spray paint lol Even the gasket looks new or very low hours of use, but I have a new one on the way with all the other seals under the powerhead. Should have zero leaks with this puppy when im done.
 
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