Normal operating engine temp?

Surface Interval · **Posted:** Sun Jan 26, 2014 10:34 pm

The three previous topics (as of today) from hail mary discussed his boat's performance issues. An exhaust restriction was causing a loss of performance and enough exhaust back pressure to blow a rubber hose on the port exhaust elbow. Normally there is very little or no exhaust back pressure. One of the few things that can cause this restriction is an unattached flapper valve lodged in the transom area of the exhaust system. I experienced this with my boat several years ago. In addition to the interaction and entertainment value, one of the great things about this forum is the ability to share information to get help or to help out someone else. Thanks to everyone that has helped me out in the past.

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

i started experiencing performance problems like hard to plane the boat and not reaching full speed, the rpms would be at 4500 and the boat was only doing 25 mph , then the exhaust boot hose began bursting. The exhaust flappers had fallen way down into the exhaust and was clogged
as a new boat owner I wasnt exactly sure what was going on but i knew something was not right.. and the mechanics did not see the flappers with the inspection camera and after 3 blown hoses I arrived here and got the answer and printed it and showed to mechanic. they took it all apart and cleared it out and there was the flappers as well as rust chunks from the previous exhaust risers that they had replaced. so now happy boating :lol:

LouC · **Posted:** Mon Jan 27, 2014 7:52 pm

hail mary wrote:

and the mechanics did not see the flappers with the inspection camera and after 3 blown hoses I arrived here and got the answer and printed it and showed to mechanic. they took it all apart and cleared it out and there was the flappers as well as rust chunks from the previous exhaust risers that they had replaced. so now happy boating :lol:

Well they if they changed the exhaust hose, they would have seen that the flapper was not there, now the metal rod that it pivots on was still there, why did they not remove the drive and go looking for it? Did they think it just vaporized into thin air? Instead of depending on a hi-tech camera, they should be thinking based on logic, where would the missing flapper be?These flapper valves can get melted easily if the cooling water to the exhaust system gets cut off, either because of a bad impeller, or clogged risers. If you have an overheat, then you have to check these. Not only that, but the water tube gaskets in the drive can get melted in a severe overheat. When that happens, even if everything else is OK, you can get an overheat with the boat on plane because when the upper gear housing lifts out of the water, the leaky gaskets will suck in air.
When I had my overheat last summer, right away I ordered new flappers and water tube gaskets because I knew I'd be replacing them. One was melted on the metal rod, one was right in the middle of the exhaust housing at the bottom of the Y pipe.
And, I'm not even a trained boat mechanic. A self-taught do it yourselfer, 42 years worth.

So note to you all, if you have an overheat, make sure to check the flappers, if your engine has them.
And, like I said in earlier, get an IR temp gun and monitor the temps of your exhaust system. You will spot a problem in time that way. It should not be higher than 130-140*F after coming off plane and should be at about 100* idling. If you can't keep your hands on the risers they are too hot, because most people can't tolerate temps of over 140*.

If the mechanics water tested the boat on plane and monitored the exhaust system temperatures they would have known for sure that there was still a problem. A lot of that hot exhaust gas was not getting out so for sure it was hotter than normal.

hail mary · **Joined:** Tue Dec 17, 2013 11:50 pm **Posts:** 33

yes you are right , so needless to say i will not be taking my boat back to this place...Ever. , The mechanic was a young guy that did not have the experience needed to be working on my boat or any boat and the owner was not so helpful either , really. also Im a contractor and when I work in someones house I make it look like i was never there and clean up my mess and lay down drop cloths. These guys trashed my boat, got my carpet dirty and got oil on my bench seats which i had them clean before i would take my boat back,

rpengr · **Posted:** Mon Jan 27, 2014 10:02 pm

LouC wrote:

One thing you can do now since its running well and normal temps, is to get an IR temp gun from Radio Shack. Take readings of the thermo housing or the intake manifold right where it bolts on and readings of the manifolds/risers. This will give you baseline of normal temps and will tell you things the temp gauge will not.
With a warmed up engine my temp gauge will say 160-165, intake manifold under the therm housing will say 155, ex manifolds will read 100 or so at idle and will go up to 130 after coming off plane but quickly go back to 100. If I see temps higher than that I start looking for problems.

+1
and post your findings here for future readers: http://www.smwebhead.com/phpBB3/viewtopic.php?f=11&t=10101

www.iFourWinns.com

Normal operating engine temp?

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