Mercruiser 165 inline 6 rebuild.

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Hi Guys:

I have a 1976 Slickcraft/Grew SS215 with a MCM 165 inline six in it. Over the past few years my hobby has become an obsession and along with my friend John, we've rebuilt 5 inline sixes. I visited all of the marinas and marine mechanics in the Greater Vancouver area and left my name and address with a standing order to buy any of their MCM 165 tear outs for scrap value. In short, I get a call every other month and take half of them. Yesterday I purchased a pair of fully dressed running engines for a ridiculously low price with the intention of rebuilding them for fun and maybe sell them on in the future. I've received so much help from this forum that I intend to do the best I can to document the tear down and rebuild process for one of these engines.

As I've got a full plate in other areas it may be sporadic but I'm going to try my best to pull it off and hopefully be as good as some of the other threads on this site. What do you guys think? Please let me know.

kilowatts
 

jasoutside

Supreme Mariner
Joined
Dec 20, 2009
Messages
13,269
Re: Mercruiser 165 inline 6 rebuild.

I'd love to see that sort of work documented. I for one would really appreciate that kind of education.:)
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Mercruiser 165 inline 6 rebuild.

Hi Guys:

Thanks Jason for your comments. I was actually thinking of your thread to emulate so I don't know about providing any education as I'm strictly a "manual in one hand and a wrench in the other" kind of mechanic.

Yeah Wood, I thought about that but thought the word "rebuild" made it fit. I guess the moderators will ultimately decide, eh?

kilowatts
 

el toro

Petty Officer 3rd Class
Joined
Mar 2, 2008
Messages
77
Re: Mercruiser 165 inline 6 rebuild.

Hey Kilowatts, that sounds great to me as I just purchased a boat this spring with an inline 6 in it and it's having overheating issues. So I'm looking to learn all I can about these motors. I'd love to hear any words of wisdom you have.
 

mike165

Petty Officer 2nd Class
Joined
Apr 14, 2011
Messages
196
Re: Mercruiser 165 inline 6 rebuild.

Hey Kilowatts, that sounds great to me as I just purchased a boat this spring with an inline 6 in it and it's having overheating issues. So I'm looking to learn all I can about these motors. I'd love to hear any words of wisdom you have.
Have a look at the riser to see if it is blocked and not leting the water flow thru quick enough,had the same problem and a new riser fixed it
 

Fordiesel69

Lieutenant Junior Grade
Joined
Sep 18, 2009
Messages
1,146
Re: Mercruiser 165 inline 6 rebuild.

Hi Guys:

I have a 1976 Slickcraft/Grew SS215 with a MCM 165 inline six in it. Over the past few years my hobby has become an obsession and along with my friend John, we've rebuilt 5 inline sixes. I visited all of the marinas and marine mechanics in the Greater Vancouver area and left my name and address with a standing order to buy any of their MCM 165 tear outs for scrap value. In short, I get a call every other month and take half of them. Yesterday I purchased a pair of fully dressed running engines for a ridiculously low price with the intention of rebuilding them for fun and maybe sell them on in the future. I've received so much help from this forum that I intend to do the best I can to document the tear down and rebuild process for one of these engines.

As I've got a full plate in other areas it may be sporadic but I'm going to try my best to pull it off and hopefully be as good as some of the other threads on this site. What do you guys think? Please let me know.

kilowatts

Sounds awsome. But you may be surprised they run as is. If no cracks or blown HG, they just run forever......
 

el toro

Petty Officer 3rd Class
Joined
Mar 2, 2008
Messages
77
Re: Mercruiser 165 inline 6 rebuild.

Have a look at the riser to see if it is blocked and not leting the water flow thru quick enough,had the same problem and a new riser fixed it

Hey Mike, that's what I thought it would be too but i just replaced the riser and the water pump in the leg. Fired it up for the first time this past weekend and it overheated on the muffs within 5 minutes. Now I'm scratching my head. The flow looked good coming out the outdrive too. The block and manifold are FWC so I don't see how there could be a blockage in there but maybe I'm wrong. I haven't tested the recirculating pump yet but it was turning with the belt...???
 

mike165

Petty Officer 2nd Class
Joined
Apr 14, 2011
Messages
196
Re: Mercruiser 165 inline 6 rebuild.

Hey Mike, that's what I thought it would be too but i just replaced the riser and the water pump in the leg. Fired it up for the first time this past weekend and it overheated on the muffs within 5 minutes. Now I'm scratching my head. The flow looked good coming out the outdrive too. The block and manifold are FWC so I don't see how there could be a blockage in there but maybe I'm wrong. I haven't tested the recirculating pump yet but it was turning with the belt...???
Have a good look at the manifold take the end caps off,and the water pump make sure it,s clean
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Mercruiser 165 inline 6 rebuild.

Hi Guys:

Thanks for the interest in this thread. I picked the 2 engines up yesterday from the marina. They came out of a big old flybridge cruiser which was delinquent in the storage fees. The boat was no value so they crushed it after taking out the engines. The dump won't take them and their only alternative was to sell them to me or for the scrap yard to pick them up for free. They are freshly rebuilt and fully dressed with San Juan Engineering closed cooling systems and aftermarket Jabsco raw water pumps to supplement the water pump in the outdrive. I don't really know why the pumps were attached but I plan on removing them anyway and bringing them back to stock specs. I plan to put them both on engine stands until I have the time to attack them. For the record I paid $150.00 each for them! The last time I sold a used San Juan cooling system I got $700.00 so I don't see how I can make too many mistakes, eh?
First impressions:
The oil is fairly clean with no water in it. The cooling system is full of green anti-freeze. The plugs are all clean and look pretty new. Points need to be replaced. Wiring harness has been bo-jacked. Gaskets have been replaced with the rebuild. Someone painted the block electric blue! Manifolds seem to be clean and tight with no sign of leakage or corrosion. I tried a few bolts and nuts and non of them were seized. One broken carb, I think the mechanic who took out the motors just kicked it over! One broken oil pan plug, oil leaked all over the back of the truck. 160 degree thermostats in each motor. The rest of the parts seem to be OK but filthy and greasy. 2 bent spark guards on the carbs. Good hoses and fuel lines. I ran the serial numbers and they are both within 13 numbers of each other and both 1978 vintage.
So far, so good. I'll keep you in the loop.

kilowatts
 

thx1979

Recruit
Joined
Jun 12, 2011
Messages
1
Re: Mercruiser 165 inline 6 rebuild.

I need some 165 love!

I have a cracked water jacket and need to find a new block or engine. I'm new to this forum and to boating and am looking to get my boat up and running. I have a mid 70's fiberform 19'. I live in North Vancouver, I'm a landscaper and I would love to go out on my boat. If you have any suggestions or would be able to help please let me know.

Tyler
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Mercruiser 165 inline 6 rebuild.

Hi Guys:

thx1979 you have a PM.

kilowatts
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Mercruiser 165 inline 6 rebuild.

H Guys:

With great regret I have to report that I'm not going to be able to finish this thread in the manner to which the readers on this site have become accustomed! I've just got too much on my plate at the moment. I'm building a new house and trying to keep my business humming along so please accept my apologies for making such brash promises but I will get back to this project later in 2012 and make the best thread I can at that time. I'll still be reading along with everyone else though.

kilowatts
 

Ike-110722

Chief Petty Officer
Joined
Sep 3, 2007
Messages
408
Re: Mercruiser 165 inline 6 rebuild.

Too bad.. I was hoping to glean some good info from this thread. I just bought a 1972 Sea Ray SRV 190 with a Mercruiser 165. I haven't really done anything yet except clean it up a bit as the boat has been sitting for several years. The starter is new but appears to be an automotive starter, and the distributor is definitely an automotive part. The fuel lines have never been change in 39 years. How do I know that? they are the old SAE J30 hose from the 70's. The manifold is pretty rusty on the outside, and there is a lot of rust on the other side of the engine block. But strangely enough it is relatively clean. No oil in the bilge, no oil all over everything. So who knows it may be all right? But where to start is the question? I really don't want to haul it out if I don't have to.

Also, you probably know good sources of parts. That kind of info would be very valuable.

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Last edited:

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: Mercruiser 165 inline 6 rebuild.

Also, you probably know good sources of parts. That kind of info would be very valuable.

Ayuh,... Start a thread of yer own, insteada hy-jackin' this 1, 'n you'll get All kinds of answers...
 

Grew15

Recruit
Joined
Aug 14, 2012
Messages
1
Re: Mercruiser 165 inline 6 rebuild.

Grew 165 mercruiser
Hi Kilowatts. I have read your thread and found it very interesting. I have just picked up a 19ft Grew with a 165 mercruiser engine that is working but in need of some attention. I have bought the boat for a winter project more than anything as the Hull, transom, and stringers seem to be in good shape, and I need to keep Busy in my shop over the winter, But i would like to rebuild the 165 mercruiser. so... i hope i can run questions off you with problems i am sure to have. If you have a mercruiser 165HP rebuilt...I might even be interested in buying one from you if its in excellent condition along with trading you the one I have IF you are interested? I live on Vancouver Island so am not that far away.

Well...Thanks for any info and tips you could provide with this endevour!
 
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