1997 4.3L one exhaust manifold normal temp other too hot

[idflyfisher]

Just got my first boat and need some help. the port side manifold is at normal temps, but the starboard side is way too hot. What could be causing this?

Thanks in Advance

 

[Don S]

Re: 1997 4.3L one exhaust manifold normal temp other too hot

Lack of water causes that. It's normal for one side to run a little warmer than the other, especially on muffs, but it shoudn't get really hot.

The elbow or manifold could be plugged up, but the first thing I would check would be the impeller. Which drive do you have Alpha or Bravo?

 

[idflyfisher]

Re: 1997 4.3L one exhaust manifold normal temp other too hot

It's an alpha. I have the lower unit off and am waiting for gaskets that were bad while I was in changing the impeller. I am doing the thermostat while I wait. When you say obstruction, what are you talking about, and how difficult to check??
Thanks Don

 

[idflyfisher]

Re: 1997 4.3L one exhaust manifold normal temp other too hot

OK. So I just tested the boat after changing the impeller and puting in a new thermostat. I have lots more water coming out of the sterndrive,....but now both manifolds are too hot. The water coming out of the sterndrive is cool. Is it possible that I put the tstat in upside down??? I had the spring side so that it is toward the engine. Thats how I remember it coming out. Is that correct?

 

[idflyfisher]

Re: 1997 4.3L one exhaust manifold normal temp other too hot

pulled the tstat and retried...same result. investigating further I am not getting any flow into tstat housing from lower unit, but have water flowing out of prop and vents when engine in running. did I not get the fit right when I put the lower unit back on??