exhaust manifold temp

[garyfink]

When I run the boat on the muffs the exhaust manifold stays cold to the touch. When I run it in the pond the exhaust manifold get's warm to the touch not screaming hot just warm. Then engine is solid on 140 which is normal. Should I suspect the water pump in the outdrive or a clogged exhaust man.

 

[Bondo]

Re: exhaust manifold temp

Ayuh,... Welcome Aboard,... sounds pretty normal to me...

When was the impeller last changed,..??

Saltwater, or fresh,..??

What motor,..??

What Drive,..??

What vintage,..??

 

[garyfink]

Re: exhaust manifold temp

I just bought the boat this summer and I've spent most of the time redoing the what the last owner did. He did say he just had the impeller changed but at this point I don't think I can trust him.
The boat is an 85 stingray with 140I and alpha one out drive. The motor now runs impecably. After having it in the water for the second time I'm begining to think I can trust it now. I am planning a total waterpump replacement in the future, but probably not before the spring. I can squeeze the hoses and the feel full. I'm really leaning towards a somewhat clogged exhaust manifold. It's a fres water boat for now anyway.

 

[NHGuy]

Re: exhaust manifold temp

On muffs you only need half water pressure from your water hose. If you have it higher than that the water coming through is cooling the manifolds more than the drive pump will. I read that the drive pump should do around 4 gallon per minute on my 1.47 ratio drive at 1000 rpm, so yours should be a little more, maybe around 4.5 to 5 gpm.
They say the manifold should be warm enough that you can touch it but hot enough that you don't want to stay in contact with it.
So, yes. Not a temperature problem.

 

[tpenfield]

Re: exhaust manifold temp

When I run the boat on the muffs the exhaust manifold stays cold to the touch. When I run it in the pond the exhaust manifold get's warm to the touch not screaming hot just warm. Then engine is solid on 140 which is normal. Should I suspect the water pump in the outdrive or a clogged exhaust man.

What you are seeing (and feeling by touch) is normal. you have no issue. Happy boating.

 

[garyfink]

Re: exhaust manifold temp

thanks everyone looks like everyhting is good. this forum is great