Honda BF8A Last Attempt Before Throwing it Away

[Oceannavigator]

This doesn't involve pulling the head, so it seems more appropriate to have a new topic.

This problem is so vexing.

The motor has water in the lower cylinder, so it only runs on one cylinder, the upper one.

It runs ok on one cylinder for 2-3 minutes, then a bunch of oil gets into the working cylinder, causes a smoke show and nearly (or completely) stalls the engine.

From there, it recovers to run ok for another 5 minutes, then more oil gets in the working cylinder, smoking and stalling or nearly stalling.

It repeats like this over and over and water is in the lower cylinder.

I replaced the head gasket. It ran great on 2 cylinders for about 10-15 minutes, though for the first 3 minutes only the one cylinder was working, as it warmed up after the head gasket install.

I have water still getting in the cylinder after head gasket replacement.

Throw it away at this point?

I mean, I make about $500 a day at work. 4 days of screwing with this thing is a new one.

It starts to become less and less intelligent to keep trying to fix it.

This is a last ditch thread... any ideas what could cause this? I don't know the exact geometry of every part inside this engine, so it's hard to picture where the water and oil flow and how both are getting into the cylinders, yet the crankcase oil shows no sign of water in it and water is only getting in one cylinder, while the other works just fine (until the oil floods in).

Answer this question.-----------do you have spark on both leads that will jump a gap of 1/4" ( 6 mm ) or more on both leads ?-----------Have you checked valve clearance ?

Spark is strong, have not checked valves because it runs great when not flooding with water/oil.

 

[Deanmck]

Sadly from the way I see it. If it's not the head gasket. You could try retightning to check the torque settings. It sounds like a warped head. That really is not good. Not unfixable, but not good.

 

[jgmo]

I agree with Deanmck,
It's either a warped head, a warped block deck or there is a crack in block or head. Without pressure checks you likely will never locate a crack but you could (should actually) use a straightedge to assess for warpage. These outboards can be valuable for parts but it can be time consuming to get them sold and that seems to be an issue for you. Sorry you're having trouble.

 

[mf70]

As was said, aside from a crack, the only place the water could come from is the head/ block joint.

You can check for a warped head with a straightedge (once the head's off, of course).

I've heard of "magnaflux" as a tool for detecting cracks, but I don't know if it applies to aluminum castings.

 

[pilotart]

It's value as a "parts engine" would be several hundred dollars, the most from parting it out piecemeal on eBay and Craigslist, but that takes time.

Water in one cylinder (but none in oil) and oil in other cylinder points to two different issues, both 'head' related. I can't see any "Last Attempt" not involving head removal as a starting point.

More time and money, but looks like OP has "Had It" with this engine. A repair should involve taking the Head into a Machine Shop. They would plane the gasket surface and check for voids from combustion chambers into water jacket. The "oil into cylinder" would most likely be a valve guide issue. A Machine Shop Bill of <$200 including a "Valve Job" should do it.

If it has corrosion voids I don't know if that's repairable, but should be visible before taking it in to a shop. Alternate solution for that would be an eBay head that would still need taken to Machine Shop before installation.

A void in cylinder wall seems less likely due to no water in oil and a broken oil ring could also introduce oil into cylinder. A little more time and investigation on recent head gasket job would likely prevented present dilemma.

I have no room to criticize the OP on this at all. 20 years ago, I had a 'loved' 120 Mercruiser engine that needed (I thought) a replacement cylinder head. I had a good used head in reserve so took it into Machine Shop for conditioning and valve job. Then after pulling original head, found a cracked cylinder wall and scrapped the boat (1973 Aristocraft Nineteen). I later sold that head on eBay for much more than the Machine Shop bill, also the prop and few other items I had stripped before disposal.

For the type of use the OP has, it would seem that one of these new Electric Outboard Motors and a Solar Battery Charger should be investigated.

I can imagine these short runs on a gasoline engine would be less troublesome done with electric power.
Art