mercruiser 228, 305 keep overheating any ideas!!!

[betayv]

hi there, thanks for all the help and info that you guys put on this forum here is my history I have a 1980 mercruiser with a 228 o 305 motor I have a new water pump installed on my outdrive, new thermostat housing, new risers and manifolds, new circulating pump for the motor, I have a digital temp gun just in case my gauge wasn't working, and the engine when is running on muffs on idle the tem is 160 I put the boat in the water and going slow about 8 miles almost idle the temp is 175 if I go hald way throttle the temp go up to 200 if I put the boat back on idle the temp go down to 165, here is more info I use a 160 degree thermostat and I took the thermostat out and didnt make no diference same temp any ideas thanks.

 

[erikgreen]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Where are you measuring the temp with the IR thermometer?

If you're measuring alongside the carb, there are places where the temp on the intake might well be above 200, if you're measuring on the exhaust manifolds they could have hotspots.. if this is the case, how old are they?

You should be checking engine temp right on top of the thermostat.

You could also try temporarily disconnecting the water intake hose from the engine circ pump while running to make sure you're getting a good flow of water... if you're not getting enough into the engine due to blockage, then it won't cool.

Erik

 

[betayv]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Where are you measuring the temp with the IR thermometer

hi there and thanks for your help Im measuring the temp right on the top of the thermostat housing and my risers and manifolds are brand new just put them last week, hey just in case what hose I should disconnect and check if I have enought flow of water If I dont have enough flow of water what I should do? thanks

 

[Bondo]

Re: mercruiser 228, 305 keep overheating any ideas!!!

hey just in case what hose I should disconnect and check if I have enought flow of water If I dont have enough flow of water what I should do? thanks

Ayuh,......

The lower hose, portside of the T-Stat housing is the In-coming line from the Drive......

Speaking of the T-Stat housing,.... Did you replace it with the Exact same copy of the original, with the check-balls,..??
And,....
When you replaced the Impeller,.....
Was the old 1 completely Intact,..?? Did you Flush out the line I mentioned above to flush out any debris between the Motor,+ Drive,..??

 

[betayv]

Re: mercruiser 228, 305 keep overheating any ideas!!!

hi there thanks for the help and yes I replace the housing with the same copy of old housing, I replace the impeller 2 months ago and the old impeller was complete destroyed I pull the hose coming in from the outdrive to the oil cooler and the rest of the hoses and flush them all, by the way I pull the hose and I dont see that much water coming out. what I should check? thanks

 

[sarantis]

Re: mercruiser 228, 305 keep overheating any ideas!!!

make sure the water hose from bell housing to the transom is not bent.Bend down and check it.Assembling my new water pump housing i had made a mistake puting the top rubber seal over the top of the housing instead at the top of the inner of the housing where there is its "nest".The overheating may has damaged the intake manifold gasket but i don't know if you should expect in this case bubles to the water circuit since these gaskets have in front water passages,or you should see water in the oil.So leave this possibility for the last.I've heard the particles of a destroyed impeller may go to the engine but where?Don't neglect to report back.I'm not sure i ve solved my temp problems yet.But the way you describe the problem indicates a big and simple mistake in assembling.Good luck!

 

[sarantis]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Another check is to pull the outdrive and put the hose garden at a medium flow to the inlet hose of bell housing and notice the temp differences.

 

[betayv]

Re: mercruiser 228, 305 keep overheating any ideas!!!

hi there and thanks for your help the hose from bell housing to the transom is bent let me ask if I want to replace this hose I have to pull the otdrive? or is another way to do it, what I dont want is take the outdrive apart and them have problems with my shif cable thanks again.

 

[sarantis]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Hi Key West, I've been there when working at CENTURY cruising ship,nice place for cruising.
First of all replace it only with factory bent hose.It's extremelly dificult to replace it without removing the outdrive.A guy in this forum ,about a month ago or two said that he pulled the one end (bell housing end) he led a cable through the hose until it got into the brass hose at the transom ,then pulled the rubber hose out and led the new one in.He said it was easy. Good luck!

 

[betayv]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Hi There And Thanks For The Help You Know If I Take The Outdrive Out To Replace The Hose Will Mess My Shifting Cable Or Not Thanks.

 

[sarantis]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Taking out the outdrive has nothing to do with the shift cable.Unless you mean about synchronization .Before uninstalling the drive you put full throtle forward gear and when installing it you turn the shift shaft that engages to the bell housing straight forward.But better take a look to the manual because you may need to pull a little out the bell housing .If you don't have the manual ask the link.It's free online and would help you a lot.

 

[betayv]

Re: mercruiser 228, 305 keep overheating any ideas!!!

hi there thanks for your help I SOLVE THE problem what happen was the hose from bell housing to the transom was obstructed with parts of the old impeller I took out the hose inlet hose from the tramsom without taking the outdrive apart and them I disconect the hose from the oil cooler and then put a garden hose with a clamp and give some pressure and I see a lot of parts of my old impeller coming out after that I have plenty water flowing I put all the hoses back and I star my motor and AHHHH big diference I use to run 170 in iddle with muff now is 135-140 really nice thanks again for your help!!!

 

[erikgreen]

Re: mercruiser 228, 305 keep overheating any ideas!!!

I thought you said you flushed all those hoses?

 

[sarantis]

Re: mercruiser 228, 305 keep overheating any ideas!!!

Glad to help you,actually you are the first one that i help!