Recommissioning a Honda BF100

rollsfixer

Recruit
Joined
Jun 3, 2009
Messages
3
Hi All,

I have a BF100 model B100L that was made in 1981. It has been aux power for a sailboat, and not used a lot.i.e., never more than getting in and out of the marina. However, it has been sitting for several years, and mud-dauber wasps have built many nests inside the cover and intermediate housing, which need to be cleaned out. I know I also need to replace the water pump impeller based on age. Currently the engine has poor compression (30 and 95 psi, and I am concerned that in the past it may have sucked in some of that dried mud and scored up the cylinders. Also I read elsewhere on this forum that one owner fixed low compression by adjusting the valves.

I would like some general guidance on what to do to address poor compression, I am not opposed to taking it apart and replacing rings, grinding valves, etc. as needed, but perhaps there is a methodology including checking valve adjustment etc. that possibly avoid a teardown.

Thanks in advance for any suggestions on how to proceed.

p.s., I'm new here. I see I am called a cadet. Interesting. Is that based on numner of posts or time enrolled or something like that? I actually feel like a machinist's mate 1st class based on experience with other engines, but fixing on this Honda critter is new to me. Oh well call me whatever; I know who I am.
 
Last edited:

Nick on the Bad Habit

Petty Officer 2nd Class
Joined
Dec 11, 2004
Messages
144
Re: Recommissioning a Honda BF100

The compression can be affected by an air restiction from the intake. Make sure that the screen in front of the carb is clean and that you opened the throttle fully, also try squirting some oil into the cylinders to seal the oil rings. The compression test should be done on a warm motor. The link below is a download of your outboard.
http://novigrad.sitesled.com/1673.pdf
Good luck, Nick
 
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