63' Evinrude 40hp (40353D) Steam Trail?

[JJBoatr]

Morning,
I recently got my 40hp running and it runs great. My question is; Is it normal for this motor to have a steam trail coming out of the upper exhaust outlet? It has the quiet exhaust housing. I've also noticed the exhaust manifold cover gets warmer than I am used too on my 22ci OMC motors. It doesn't get too hot to leave your hand on it but it's not cool to the touch like I am used too. Has no symptoms of getting too hot such as leaning out etc. I have not changed the thermostat yet. Your experience is appreciated.

 

[mla2ofus]

Sounds like it's due for a new water pump impeller. My '53 15HP 'rude did that until I replaced the impeller.
Mike

 

[JJBoatr]

Impeller is brand new. The drive shaft seal on the housing seamed loose on the drive shaft. Could that be letting water escape?

 

[flyingscott]

Are you sure it's steam and not exhaust?

 

[JJBoatr]

I'm fairly sure. It's white not blue. Spits a good amount of water out with it once the thermostat open.

 

[F_R]

Steam is normal on that motor, under certain conditions (weather, air temp, speed, etc. Does the spray vary according to thermostat status? It should open and close at any time, according to speed, lake temp, etc..

 

[JJBoatr]

Yes the steam/water output varies when the tstat opens and closes. Puts out more steam at idle but if you advance the throttle a little the steam lessens but it's still there. It steams all the time, today it's 80 degrees, water temp is 73. By what you've described it must be normal, just different than what I'm used to. I would expect steam with cooler temps, just not on a warm day.

 

[oldboat1]

I would just monitor engine temp -- surface temp on the top of the head (exhaust cover gets hotter). Head temp should be well under 160F (Look for 120-140F). An IR gun is a good tool to have.

A functioning t.stat is also important on that motor for the auto choke, if using it.

 

[JJBoatr]

I left my pyrometer at home as I didn't think about checking the head temp with it. I will next time I'm out for sure. Yes I'm using the how water choke and it actually works well. Fingers crossed it continues to work

 

[oldboat1]

All sounds good.

 

[JJBoatr]

It seems so. I'll get some heat readings and report back in a week or so