New 3.7 owner...basic questions!

[Rocky_Road]

Hi everyone!

I just purchased a vintage boat with a 170 hp, Mercruiser 3.7 (470) engine...and need the basic information, before I receive a detailed manual.

What is the recommended oil for this engine?

My engine is closed loop cooling...anything special about the coolant?

Very important...what is the required fuel rating?

The outdrive is the Alpha 1...any info would be appreciated.

Thank you for any replys!

 

[TilliamWe]

Re: New 3.7 owner...basic questions!

Hi everyone!

I just purchased a vintage boat with a 170 hp, Mercruiser 3.7 (470) engine...

Thank you for any replys!

My condolences. Are you still thankful for any replies?!

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

My condolences. Are you still thankful for any replies?!

Counting yours...no! LOL

I take it that you are not a 3.7 fan.

That's cool...but I have one, and I just want to get off on the right foot. I understand that there are several prominant issues with this engine, but the seller has addressed these to my satisfaction, and I am just looking to 'pick' the brains of the wealth of knowledge residing here...for the basic maintenance info.

Hell...I also own, and love, a Polaris PWC...so what else is new?

 

[ne7800]

Re: New 3.7 owner...basic questions!

welcome fellow 3.7 owner
there not all bad, the coolent is just standard 50/50 mix and i just run reg grade gas in mine

 

[180shabah]

Re: New 3.7 owner...basic questions!

25W40 oil
Regular 50/50 antifreeze mix
87 octane is just fine

 

[Don S]

Re: New 3.7 owner...basic questions!

Well, this is a little more than just BASIC information.
But here is a link to the OEM Service Manuals for your engine and drive.

Drive Manual Go to outline and download and save each section letter at a time.

Engine Manual 360 MB, takes a while, all in one section.

 

[TilliamWe]

Re: New 3.7 owner...basic questions!

Hell...I also own, and love, a Polaris PWC...so what else is new?

Do you run a home for wayward and orphaned marine vehicles?! ha ha

Looks like the less sarcastic guys have given you quite a bit of info and study material. Good luck and have fun boating.

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

Well, this is a little more than just BASIC information.
But here is a link to the OEM Service Manuals for your engine and drive.

Drive Manual Go to outline and download and save each section letter at a time.

Engine Manual 360 MB, takes a while, all in one section.

Killer files! But I got them downloaded...many thanks!

I will be 'reading' for a couple of nights...or more.

Thank you to ne7800, and to 180shabah...just what I was needing!

Question to 180shabah:

Why the suggestion of 25w40? I am not familiar with this grade...is this based on personal experience? I am running in pretty moderate temperature range (North Florida), and do not see any freezing temperatures.

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

Do you run a home for wayward and orphaned marine vehicles?! ha ha

Looks like the less sarcastic guys have given you quite a bit of info and study material. Good luck and have fun boating.

Probably should get some sort of tax relief for 'feeding' the needy!

But, truth be told...my Polaris MSX 150 has been bulletproof...and I have never been towed (knock on wood). I have, however, towed several Sea-Doos back to the launch ramp.

This 'vintage' bow rider boat is my first since my teenager years...and I welcome the challange!

 

[ne7800]

Re: New 3.7 owner...basic questions!

This 'vintage' bow rider boat is my first since my teenager years...and I welcome the challange!

so what are the details on the new boat make model year and PICS we love pics here

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

so what are the details on the new boat make model year and PICS we love pics here

Here is the eBay link to the auction...although I purchased the same boat from Craig's. The eBay link had the most pictures....

The final price was $2,900.

http://cgi.ebay.com/ebaymotors/ws/e...ame=STRK:MEWAX:IT&viewitem=&item=270283859110

 

[ne7800]

Re: New 3.7 owner...basic questions!

hey now thats a good lookin boat

 

[JustJason]

Re: New 3.7 owner...basic questions!

25w-40 is the mercruiser recommened weight for all engines.....
it is pricey... as far as oil goes. and realistically... you can run whatever oil you want. 5-30, 10-30, 10-40.... it's not going to make a difference in these engines.
On the older ones I run straight 30.
The biggest thing is that you keep up with the oil changes and check the level consistantly.

 

[Big Boat Bay Buster]

Re: New 3.7 owner...basic questions!

You are going to have a blast in that boat! That is a perfect set up for a 470. I should know, I owned an 18 foot bowrider with a 470 for a year and a half. Good power and great on gas! If that motor runs as good as it looks, you are good to go. If you boat in Fla, straight 30W oil is good. Its more important that you change at regular intervals. Have fun
Chris

 

[chiefalen]

Re: New 3.7 owner...basic questions!

Good luck, If you were in nj right now i could take you over to five boats with that motor in it.

Some want what you paid but three wanted just 500. Would have taken less.

That motor is a cancer waiting to happen.

You could get a 3.0 or a 4.3. for that money.

Oh well live and learn.

 

[bikemtn]

Re: New 3.7 owner...basic questions!

Do not worry about the negative posts. What most people do not realize is that a boat needs to be maintained...and so does its motor. 3.7s are good engines, but you need to take care of it and I do not think that the average Joe really knows how to.
I run 30w in mine and 50/50 coolant. Make sure that the coolant seals on the cam are addressed, do the alternator conversion, and keep your eye on the exhaust riser and gasket. If you take good care of this motor it will last a long time. Search the forums for 470 and you will find a good manual...and buy a manual too, but not a clymers. I have a Seloc and it covers all you need to know.

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

Do not worry about the negative posts. What most people do not realize is that a boat needs to be maintained...and so does its motor. 3.7s are good engines, but you need to take care of it and I do not think that the average Joe really knows how to.
I run 30w in mine and 50/50 coolant. Make sure that the coolant seals on the cam are addressed, do the alternator conversion, and keep your eye on the exhaust riser and gasket. If you take good care of this motor it will last a long time. Search the forums for 470 and you will find a good manual...and buy a manual too, but not a clymers. I have a Seloc and it covers all you need to know.

Good info!

The seller just had the cam 'sleeved'...and new seals installed. He has the receipts for this, and other work performed.

I am looking into the alternator upgrade, but will make up my mind when I get my hands on the boat, and see how much room I will have!

I'm going to look for the Seloc manual...as soon as I finish reading these great posts!

 

[Rocky_Road]

Re: New 3.7 owner...basic questions!

25w-40 is the mercruiser recommened weight for all engines.....
it is pricey... as far as oil goes. and realistically... you can run whatever oil you want. 5-30, 10-30, 10-40.... it's not going to make a difference in these engines.
On the older ones I run straight 30.
The biggest thing is that you keep up with the oil changes and check the level consistantly.

Thanks capt!

Any advantage to using the Mercury brand oil...if I can find it?

Also...any advantage to going to synthetic (I run syn in all of my motors)?

You mention using straight 30w in your "older ones"...are you refering to the age of the motor design? Or are you referencing the engine hours....

 

[JustJason]

Re: New 3.7 owner...basic questions!

well.... there's always going to be advantages.... as stated by the sales pitches of any manufactorer of oil.
Realistically.... as long as you use a brand name oil, and not wally world stuff, you'll be ok.
Synthetic vs dino discussion if for another thread..... a word though is if you choose to run synthetic... go 1 weight heavier and keep an eye on the level. Personally.... i'd just stick with dino oil.
and as far as runing straight weight.... straight oil is less likely to have viscosity breakdown than multi-vis is. It's all a preference.... and from what school of thought ones from.
Just stay with the above advice and use quality brand name oil, keep an eye on the level, and change it once a season.

 

[TJEli]

Re: New 3.7 owner...basic questions!

Read everything you can get your hands on about the 470 and you will know what to watch for. Keep it maintained and have fun. I have a 17'4" bowrider with a 470 and it powers the boat very nicely into the high 40s.

http://www.breezeworks.net/ has a forum with a lot of good 470 info. They are also a source for 470 parts.

Good looking boat too.


-Eli

1978 Cruisers Rally 174