help plz Overheat problem

[dead_soul79]

i have a 1987 larson dc190 runabout that has a mercruiser 3.7 took the boat out and ran good then started over heating . i'm looking for a service manual to help me fix the problem.

 

[stonyloam]

Re: help plz

Re: help plz

First thing to do is change the impeller in the outdrive. How long has it been since it has been changed? Here is your engine manual Merc #8: http://boatinfo.no/lib/mercruiser/manuals/mercruiser8.html#/0 and your outdrive Merc #6: http://boatinfo.no/lib/mercruiser/manuals/mercruiser6.html#/0 page 229 of #6 goes into impeller change

 

[dead_soul79]

Re: help plz

Re: help plz

not sure i bought the boat 3 months ago thank you for help

 

[Don S]

Re: help plz

Re: help plz

As noted, the impeller is the FIRST thing you check in any marine overheat.
I would suggest you remove the drive from the boat, to check. Since the boat is new to you, you might as well check in there as well.

The .pdf files below is just small sections from the OEM manuals so you don't have to leaf through many pages of the manual.

View attachment A1 R&R.pdf View attachment A1 Impeller R&R.pdf

I also edited the title of your thread so it actually means something. Everyone posting here wants "help plz"

 

[Eric 3.7LX Alpha 1]

Re: help plz Overheat problem

Since you have no known history of the impeller, I would replace the complete water pump assembly with OEM parts...
which would include:

Quicksilver 46-96148A 8 (Water Pump Upper Housing Repair Kit)
Quicksilver 46-44292A 3 (Lower Base Kit for an Alpha One)

 

[stonyloam]

Re: help plz Overheat problem

+1 Eric & Don!

 

[dead_soul79]

Re: help plz Overheat problem

would like to thank you all the impeller was the problem and the boat has been running cool as could be thank you all so much