Honda outboard spitting molten plastic from exhaust

[ribbony]

We came across a nice little al dinghy with a 2.5hp honda 4 stroke motor 2006 model. We bought the boat but have balked at the motor. When we tested it on the stand it ran well for a min, then spewed molten plastic out the exhaust . The chap selling it then drastically reduced the price, but is it a bargain or a trap ? He wanted $450 for it, then reduced to $300 but what are some of the possible scenarios. I kept the bits of plastic that look a bit like the Austrian noodle dish called Spatzle. He asid it may have been some sealant coming out (no recent work done on the motor).

[Daddy's Dream]

Possibly the water pump impellor coming apart? I'm just gurssing, but that would be the first thing I'd check. It's made of hard ruber and they do come apart.

[ribbony]

It was coloured hard plastic, red I think with a charred black crust. Do they have impellers in those little 4 stroke Hondas ???

[Daddy's Dream]

Back in 96 when I worked for Honda they did. (Back then they were all black). But who knows now. Seems like everything changes so fast anymore. LoL

[ribbony]

The chap selling the honda said the engine was air cooled. Perhaps it is not and that is why it is melting down when he does his demos on the trolley without any water to cool the motor Ouch.

[Daddy's Dream]

I've been searching the internet for about an hour and I haven't been able to find out anything on a 2.5..... are you sure it isn't model BF25? The BF 25 is water cooled. I looked at a listing of all their water pump kits and they don't list a BF 2.5 at all. That said if it is a 2.5 then it must not be water cooled. Which brings me to the next question. Could it be a 2 stroke? They are oil cooled. The 2.5 isn't on their list of replacement props either.

Not doubting your word. Just thinking if I can't find it on the internet I must not be asking the right questions. Or possibly it wasn't imported into the US. I'm tempted to call American Honda and to ask them myself.

[Daddy's Dream]

Oh never mind I just noticed where your at. None of this applies in your case. I should have known better then to have assumed you were in the US. Sorry about that.

They did import a 2 HP, 4 stroke outboard into the US that is air cooled. So purhaps that one is air cooled as well. Sorry I had all the wrong answers.

[ribbony]

Thanks for the research !

It does appear that it is air cooled as there was no intake on the leg for water to go in. The air cooled concept sounds good from the maintaince angle, but i wonder if they do it on the larger HP engines, probably not.

I think this coloured plastic is a sign of severe internal meltdown.

[waterworldly]

Call a Honda dealer / repair facility and explain what you see.

[cabo_sailor]

I have a Honda 4-stroke 2.5 HP. It is air cooled. However, the owner's manual cautions against running it if the lower unit is NOT in the water. I presume that some of the cooling is heat conduction through the water in addition to air.

[David M]

I would walk away from the offer. If you are not certain what that plastic is then why take the risk? If could very well be a problem that is going to cost you more than the $150 price reduction.