I'm dealing with my Honda Outboard Pre-1997 BF100D SA OUTBOARD ENGINE, . I picked up some line in the prop, removed it, then the engine died a few times and no water was coming out of the ??exit , just some pressure and a little steam, rowed in, found water in my engine crankcase, nice!, compression is still good on both clys., called a shop and they said I had to "replace 18 91251-935-004
SEAL, WATER (17MM) (Honda Code 0444240) next to the prop,
and that would fix the leak, common problem", does this sound right to you? I'm doubtful (sure would be nice and easy to fix though)??? I can see water getting into the gearbox, but the crankcase?

The seal is for the gearcase. If there is water in the gearcase, this is the most likely problem if you found line cutting into it. Like you, I see no relationship to water in the crankcase.

The water in the crankcase and no water indication can be related or it could be two different things.

No water coming out the indicator...
- Could be the impeller burnt up
- Could be debris in the water passage or part of the impeller (I guess that qualifies as debris)
(used some compressed air to **** back through the indicator hole and see if you can loosen
it up...if it is debris)

Water in the gearcase could be...
- ****n head gasket
- motor not coming to temperature (thermostat stuck open)
- motor could have overheated (bad impeller, thermostat stuck closed, debris)
- if you have a plastic oil fill, it could be a warped oil fill. I know it sounds crazy, but there is a
water passage through the oil fill base and the plastic fills tend to warp and allow the water
to get past the o ring to the oil fill passage.

There may be other reasons, cracks etc, but the above seem to the most guilty.

Mike

Thanks for that UM. I spoke w/ the shop again today and they thought I said the lower end, whew! I had about a cup of water coming out w/ the engine oil out of the crankcase(upper end) (I changed the oil about a month ago). I had some questions about your reply:

- motor not coming to temperature (thermostat stuck open), are you referring to condensation or how could this force water into the crankcase?
- motor could have overheated (bad impeller, thermostat stuck closed, debris), again can water be forced into the crankcase?
- if you have a plastic oil fill, it could be a warped oil fill. I know it sounds crazy, but there is a water passage through the oil fill base and the plastic fills tend to warp and allow the water to get past the o ring to the oil fill passage. Where and how would I access this to check it? I'll start searching the book again.

I was just trying to go down a list of common things that put water in the crankcase.

- motor not coming to temperature (thermostat stuck open), are you referring to condensation or how could this force water into the crankcase?
This would mostly be due to condensation. I see this more on larger motors.

- motor could have overheated (bad impeller, thermostat stuck closed, debris), again can water be forced into the crankcase?
Depending on if the motor overheated or not, debris stuck in the water passage will increase the pressure and the likelyhood of something finding its way past one of the gaskets or o rings.

- if you have a plastic oil fill, it could be a warped oil fill. I know it sounds crazy, but there is a water passage through the oil fill base and the plastic fills tend to warp and allow the water to get past the o ring to the oil fill passage. Where and how would I access this to check it? I'll start searching the book again.
This one looks easy but you can not get the screws to come all the way out without pulling the whole powerhead. Some of my customers have chosen to merely drill holes in the side of the case large enough for the screw heads and screw to come through. Check parts 13 and 14 Honda Outboard Parts Pre-1997 BF100D SA OUTBOARD ENGINE, JPN, VIN# B100S-1500001 OIL PUMP + OIL FILTER + EXHAUST PIPE Diagram
On part 14 you will see a small o inside the main o ring seal. That is where the water goes through. If the plastic fill warps, the water leaks through that hole directly into the oil pan. If yours is metal, it is less likely to warp. You have to replace the oil fill and seal.

It could be something totally different (and probably more serious). These are the most common things I see.

A compression test is definitely in order...as well as time to check the impeller.

Mike

Good one, sounds like a good plan. The compression was good, 100psi on 5 pulls, 130 on 8 pulls(3 more). I'm pretty sure she did overheat. Looked at the oil fill, 3 bolts holding on a vertical plastic piece. I did have some oil spewed over the engine.