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Exhaust manifold hot to touch

One theory may be; your engine's exhaust is coming out directly to the exhaust manifold and making its way out (4 cylinders on that side will inevitably heat things up). Secondly, if FWC, your 160-170 degree antifreeze is circulating in there too. 160 degrees is hot. Water boils at 212 degrees. If you have an infrared gun, shoot it up and down the manifold to see if temps are consistent. Are you losing coolant? Put your hands on the risers. Are they cool, warm or hot?

Just points to check before you pull manifolds.
 
M<ine run 130-140 ' F all the time. Yours are way too hot. EIther they are not getting enough water (bad impeller) or the passages are clogged with rust.

Jeff
 
It is a raw water system and should be running 140 deg like Jeff said.

Will be investigating tomorrow...headed to the lake :p:p...Hopefully, a little work and a lot of play :confused::confused: Yeh right.

I will let you know what I find.
 
See how much water is being pumped out the back compared to other boats/ yours when all was well.

Jeff

PS: If you don't IMMEDIATELY check to see if your motor(s) are pumping water EVERY TIME you start them up--cold or hot--you are fliring with disaster! I learned that ritual from my mentor 50 years ago and it has served me well.
 
Even with one engine manifold log completely blocked there would be water flowing from the other log on that engine out the back. Very hard to see water flow amount on mine because I have a swim plateform back there.
 
Ah yes! My neighbor's boat is like that. Not a good design feature.

Well, if BOTH manifolds are too hot that means not enough water is flowing. If that's the case, start with the raw water pum impeller or loose Vee belt.

Jeff
 
Checked for blockages in my cooling system this past weekend, couldn't find any. Ran a coat hanger down the tube of the cooling exhaust log in question, couldn't feel anything out of the norm. Ran the logs were cool this time. Got my niffty IR temp gun (thanks Jeff):D OB log running 115 deg, inbd log runs 100 deg. GOOD TO GO :p

After thinking it over. I touched the manifold after I had been running it hard to check the advance curve...that explains the hot log...they get a bit hotter at higher rpms..duh.. Just assumed the worst.

I did find a cylinder area that was much hotter than the rest...cause for concern??

Around the plug area of 7 cylinders temp running 150-160...one was reading 210 deg. Plugged cooling passage or air trapped from dewinterizing I guess. I will check it out after I run it for awhile and see if it goes away.
 
Check to see if that plug is in tight; loose plugs can't cool properly and overheat. If that's not it...I'm stumped.

Jeff
 
Learning something everyday !! I will check that plug and see what is going on with it.

Starting a new thread for spark plug education :D
 
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