Evinrude 2hp Steam Engine

[rupertmja]

OK, I'm fairly new to outboards but have now rubuilt three 2hps and was beginning to think it was easy until today, on my 4th. Basically, someone put a small telltale pipe on the exhaust plate. I rebuilt the engine, cleaned all the insides, new gaskets, new pump etc, and blocked off the telltale as I didn't think I'd need it. Started it up and it was getting hot and no water coming out the four holes on the back. Hmm. OK, so I refitted the teltale pipe. Water came gushing out for 20 secs than, les and less, then, steam. Pulled the powerhead, head, cleaned everything, rebuilt it, twice, same result. The only thing I can think it to be is that the water is leaking out back down the pipe somehow before it gets up into the engine - so I have changed the entire leg for a spare I had but something tells me it will not work - have to wait till tomorrow now. Oh, and I checked that the pump works - my method was to connect an old crankshaft to my electric drill to drive the leg - worked great. Anyone been here before? I need ideas to turn my steam engine into a normal one. Baffled, Rupert

 

[F_R]

Re: Evinrude 2hp Steam Engine

Can't say for sure that this is it, but suspect an exhaust leak into the water pump. Running it on a drill, there is no exhaust so no leak into the pump. Likewise, when you first start it there is no exhaust.

Again, not sure about the 2hp, but many larger motors have a water bleed hole from the pump outlet, keeping the well around the drive shaft full of water so exhaust cant blow into the pump through the drive shaft hole.

 

[tashasdaddy]

Re: Evinrude 2hp Steam Engine

it sounds like the tale tell hole goes into the exhaust, once running the exhaust has more pressure, backing up the cooling system. the tale tell has to be into the cooling system, before the exhaust. you may need to change the exhaust plate that has been screwed up. they cooling system finally drains into the exhaust, to exit the motor, and cool the exhaust.

these are bigger motors but the principle applies.
http://forums.iboats.com/showthread.php?t=222677

 

[rupertmja]

Re: Evinrude 2hp Steam Engine

The peehole insert definitely goes into the water route and not the exhaust. I changed the leg for another one and it is just the same. If I block it off a bit of water sprays out of the back four holes so maybe it is normal? If it didn't have the peehole I'd never have known about the steam anyway. Other than that, with new rings and everything it purrs great - just don't want to destroy it. I'll remove the peehole and block it off.

 

[slasmith1]

Re: Evinrude 2hp Steam Engine

Are you running this in a tank or on a hose?

 

[Rick.]

Re: Evinrude 2hp Steam Engine

Have you any reference as to how hot it's getting? (actual temperature) I'm thinking (which has caused problems before) maybe the pee hole tap is on the outlet side of the stat. If it is that could explain the steam and erratic flow? I would think the water pump discharge is sufficient to push water out the pee hole and the holes on the back of the leg at the same time. If your doing this in a tank make sure you have the water high enough. It makes quite a difference to the pumps output. Good luck. Rick.

 

[F_R]

Re: Evinrude 2hp Steam Engine

rupert, Since you seem to be pretty familiar with the 2hp motors, I assume you realize that the water spray out the relief is sort of unreliable. It only blows out by chance. Sometimes it just runs down the inside and never sees the holes. I assume you also realize that the exhaust cover plate is not water cooled except along one edge and gets hot as blazes. Same for the cylinger head, it is not water cooled except for the edges and gets dang hot around the spark plug.

 

[rupertmja]

Re: Evinrude 2hp Steam Engine

Yes, I think you are right (re last post) - they do run kinda hot. The head gasket has small holes in it but I doubt the water gets much chance to get in there as it rises up thru the barrel area - it'll take the easiest route - straight up and through to the next chamber next to the exhaust and then the water that is in the head will likely boil and turn to steam. The four holes on the back - I hold a dry cloth against it and see if it gets wet and it does, a bit, which means water comes thru.

And yes, I run it in a tank, which is the only way for a small engine. Ran it today for ten mins and it seemed fine with the peehole attachment removed.

Thanks for the advice.