Torque Sequence :: Mercruiser Head 165 HP Inline 6

MercMonster

Petty Officer 2nd Class
Joined
Jun 3, 2007
Messages
151
I'm looking to see if anyone has the torque sequence for a mercruiser head for a 165HP Inline 6. As posted earlier, I have a block with GM 82 stamping. So believe that's what I'm working with here. Still waiting for the manual to arrive (is coming postal). I'd like to get a head start on removing it today, while I have the time and gumption. Got the spark problem fixed and put on the muffs, she is singing along, but dumping water into the oil. Also, the oil pressure is low (about 20-25 lbs. on the gauge). Can this be attributed to water in the oil or is it necessarily a pump going bad? Bad gauge? Don, per your earlier suggestion, I am replacing all the components there..... Also could use the torque sequence for the exhaust manifold if anyone has that handy for reference.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6


14-10-6-2-3-7-11
13-9-5-1-4-8-12
Here ya go!......:)
 

MercMonster

Petty Officer 2nd Class
Joined
Jun 3, 2007
Messages
151
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

Sweet! Thanks there admiral!:) Is there a torque sequence for the exhaust manifold? Or just a bolt torque specification? I am just full of questions... Can I use automotive gasket for the head? I am thinking exhaust would use marine gaskets right?
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6


No, but I usually go from the center outward....
23-25#....
Use a marine head gasket for the head.......
For the exhaust, it is OK to use auto......:)
 

MercMonster

Petty Officer 2nd Class
Joined
Jun 3, 2007
Messages
151
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

When you get automotive parts that you can interchange for your boat safely, like the exhaust gasket for example, do you just give the auto parts store the engine specs? How can I be sure exactly what I have? I am guessing with mine by saying 4.1L 250 CID L6 just from what I've gathered by reading. Does this sound right for a Inline 6 with GM 82 stamped on the block? I'd like to be able to go in assured this is what I have and not have to guess....and run parts back and forth to the store. Is there an easy way to correctly ID the engine itself? I dabbled lightly in mechanics before, but had never gotten serious about it. My engine does look very similar to the 2nd picture on this page, without the breather and fan and other non-marine gadgets of course. Can the water pump be a regular vehicle water pump or is that marine also. Is there a list somewhere of what can be safely interchanged?
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6


If you have a Napa by you they have alot of marine parts & info for what you seek.....
I can tell you this: You will need to get a marine water pump......
The automotive ones won't hold up........
BTW, yours should be the 250.........;)
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

there should be a serial # on a tag above the starter for proper id. i've had 2 L6's. one had the tag, one didn't.

as for which auto parts ya can use. ya need to be shoppin at the marine parts store, not the auto store. if yer at napa or somebody that's hip to marine parts. just specifiy marine parts. if they ain't got any they'll tell ya.....mostly you need marine parts though. yer waterpump needs to be marine duty.

ya need to get the watery oil out of yer engine. watery oil can ruin your engine rather quickly........
 

MercMonster

Petty Officer 2nd Class
Joined
Jun 3, 2007
Messages
151
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

You guys are a great help here! I'll take your suggestions and visit my local NAPA and then a trip to the marine parts dealer if needed. What's the best way to get that water out of the engine. When I was at a marine service center, I heard the mechanics talking about water in the engine and something about using kerosene. Like to know the best way to flush that water.

ziggy - I hope I gave you the right info before about the engine. I believe you were the one that gave me the part number for the right service manual which I did find on ebay. It was actually Merc Volume 1 and 2 that I found for $9.99 and some change. If the info I relayed wasn't correct at the time I guess I'll have to break down and buy the right one. I'm itching to get my hands on them.:D

Thanks again guys!
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

i'm pretty sure ya need merc. service manual #2. C-90-71707
i'm baseing that statement on my 75 needing that service manual. a merc serial # would be the best way to determine what manual ya need. my 72 L6 used service manual #1. don't know if it means anything or not. but my service manual #1 has volumes 1 and 2. my service manual #2 has it all. no volumes......so did you end up with c-90-68648? ya got a good price on them volumes. i paid more than that and even then, i was happy.....ya might as well keep em for a refereance....

What's the best way to get that water out of the engine.
there's a merc service bullitin that i can't find, sorry. it reguarded water intrusion and what to do about it. from my best recollection. i had water in my oil too. a milkshake....i discovered it within 24 hrs i think. it was last fall. i changed the oil. repaired my leak. then changed my oil repeditivly till it looked clean....also after the repair and a couple three oil changes. i went to the lake and got it good and warm to help evaporate any water left over in the oil, may have changed the oil again after that even, i don't remember. i just changed it a lot.....it seemed to work ok.....but i got right on it right away.....i don't think time is in yer favor when ya have water intrusion......
 

MercMonster

Petty Officer 2nd Class
Joined
Jun 3, 2007
Messages
151
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

I just searched for C-90-71707 on ebay and this is what I found. Ah well, if its not the right one, maybe I can make my money back on there:) I found the serial #4483687, I believe that's the one I found on the merc exhaust tag and somewhere else on the engine. Know the boat is 76, not real sure about that engine though. I'll ask at the repair / parts store about the bulletin when I make a visit. I have the head and exhaust loose and ready to pull in the morning. The head is spotless, looks almost brand new inside. I'm hoping the cylinders are the same. I'll do some of those oil flushes, too. What is the best oil to use, is that one marine specific too??:)
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Torque Sequence :: Mercruiser Head 165 HP Inline 6

I just searched for C-90-71707 on ebay and this is what I found.
yep, that's the one. i have no idea why that one comes in volumes and mine didn't. i've heard that service manual #1 comes in one book too. mine came in 2 volumes....go figure......i think ya found what ya need........my serial # is 4164143.....pretty close number to yers that ya found, well, within 32,000 rounda abouts, but they still both start with a 4, :D.....

What is the best oil to use, is that one marine specific too??:)
oh no. an oil question. now ya've opened up the can of worms for sure....;)
there are many threads on what oil to use. many opinions too. too many for me to figure out so i use mercruiser 25w-40.......seems like a safe bet to me.
 
Top