Rebuilding My Mercruiser - Please Help

[Brooksie]

Thanks also for your advice on the motor. I got her all apart today and found a fried bearing. A couple of the others were well scored too. The one with the fried bearing had play and I can see how it would 'knock'. (Original problem people here helped me identify). No scorring or play on the crank thankfully.

They want over $300 for a set of frickin rings. If I got to Nappa, what do you think they'll run? To my totally untrained eye, they do not look worn at all. But I have no idea what to look for. There is no scorring in the cylinders. Let me know what you suggest as this endeavour is expensive and I have to cut costs where I can.

Anything else I should check while I have her apart? I opened up the oil pump to look for wear, didn't see any sign at all. The manual said to pack it with "petroleum jelly" otherwise damage can occur. What's that all about? What exactly do I buy?

As well, when putting it all back together, I know to lube everything with oil. Do you recommend anything other than oil?

What is best to use for cleaning the heads to prep for the new head gasket? Someone told me brake cleaner - is this true?

Many many thanks

 

[Laddies]

Re: Rebuilding My Mercruiser - Please Help

There is not a Problem useing NAPA parts, but it would help to know which engine model you have

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

For sure, it's an older (mid 80's) 165 HP Mercruiser I/O

As well, I read that if you change the 2 barrel carb to a 4 barrel - you get an additional 20 hp - is this unwise?

 

[Laddies]

Re: Rebuilding My Mercruiser - Please Help

All that engine is, is a GM 250 cu. in. engine, so parts are no problem anywhere. There is not much differance in power with a 4 barrel, everone seem to think the 200HP unit was a 250 with a 4 barrel but it was a 292CI. A 4 barrel will burn more fuel is about all

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

Thank you.

If a 2 barrel or 4 barrel are running the motor at the same RPM, would it not be the same gas useage - just a little more top end? I'd just like to see the boat be able to get out of the hole a little better - or for skiing.

The motor is rated for 4700RPM top HP output. I would think a 4 barrel would take her up to 5000, is that safe?

If anyone could answer these as well:

The manual said to pack the oil pump with "petroleum jelly" otherwise damage can occur. What's that all about? What exactly do I buy?

What is best to use for cleaning the heads to prep for the new head gasket? Someone told me brake cleaner - is this true?

 

[Bondo]

Re: Rebuilding My Mercruiser - Please Help

The manual said to pack the oil pump with "petroleum jelly" otherwise damage can occur. What's that all about? What exactly do I buy?

Vasoline..........

What is best to use for cleaning the heads to prep for the new head gasket? Someone told me brake cleaner - is this true?

Kerosine,+ a Wirebrush,+ a Razorblade.........

The motor is rated for 4700RPM top HP output. I would think a 4 barrel would take her up to 5000,

Nope,....... That's Not how it Works......

 

[Don S]

Re: Rebuilding My Mercruiser - Please Help

My guess is you don't have the 165 GM250 that laddies is thinking of, that's an inline 6 cylinder, while you have the 165 that's actually a 4 cyl. aka 470 style engine.
These are NOT GM engines. It was Mercs attempt at building their own engine. Aluminum block, with a Ford 460 head.
Even with the 4 bbl carb, the max rpm is 4800 instead of the 4600 for the 2bbl models.
The merc model with the 4bbl carb were known as the 180. 190, 488.

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

Actually it's an inline 6. But that's what I was thinking, it would slightly increase the top RPM with the same prop but also give a little more to get out of the hole. Is this not correct?

Also, I need to know how many lbs of torque to put on the cam rod bolts - please let me know. I'm guessing around 20-25lbs but need to know for sure.

 

[Don S]

Re: Rebuilding My Mercruiser - Please Help

Actually it's an inline 6.

Your comment about it being a mid 80's engine made me think it was the 470 style 165 which was a 1987 motor, while the 6 cylinder engines ended in 81.

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

The side covers that cover the valve lifters - is that a gasket or just gasket maker? That's what it looks like - just want to be sure.

 

[ziggy]

Re: Rebuilding My Mercruiser - Please Help

is that a gasket or just gasket maker?

it's a real gasket....comes with three dandy rubber washers to seal the bolt holes too......

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

Thanks, I'll get a new one then.

Question: Once I put new rings and cam-rod bearings in, do I need to allow the motor some 'break in' time? If so, what's the best way of doing so?

Thanks!!!!

 

[Coors]

Re: Rebuilding My Mercruiser - Please Help

You need to have your crankshaft checked, and your camshaft and lifters, etc. You probably need a new engine.

 

[8AteEight]

Re: Rebuilding My Mercruiser - Please Help

and your question on Petroleum Jelly......Thats just "Vaseline" 50 cents at your local Dep. store.

They use it cuz its thick, and its great lubrication.
.
.
.
.
.
know what I mean??

Also, you can get "assembly lube" in a small tube from any parts house. Its really thick stuff. and if you coat bearings, and rings, and the cam/lifters in it, Itll stay on the parts till after the break-in/when the oil takes over.

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

lol ok... thx... how long of a break-in period does it need and does that mean just let it idle? Please explain break in time a bit more - don;t want to stress the motor.

 

[Don S]

Re: Rebuilding My Mercruiser - Please Help

Ya know, if you had a Merc service manual for what you was doing, you wouldn't have to ask so many obvious questions. Plus you would find answers to questions you don't even know you should ask.
There is a LOT more to rebuilding an engine (of any kind) than just throwing some parts at it.

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

lol

Ya know; I have one and ya know; I'm here to learn and ya know; what do you care? lol

If you can't post something helpful or useful - then don't post!!!

 

[Don S]

Re: Rebuilding My Mercruiser - Please Help

I see, you're too lazy to look in the manual. Others can do the leg work for you.
No problem, I won't bother you anymore.

 

[Brooksie]

Re: Rebuilding My Mercruiser - Please Help

Don - you're a jerk. Some people are here to learn and ask questions.

If you don't like it - then stay off the forums where people are new.

 

[ziggy]

Re: Rebuilding My Mercruiser - Please Help

Some people are here to learn and ask questions.

The manual

if ya have the manual brooksie, and ya'd read the engine rebuild part. you'd read that there is

answers to questions you don't even know you should ask.
There is a LOT more to rebuilding an engine (of any kind) than just throwing some parts at it.

if ya just put some parts in it. you'll be lucky if it works. and luckier yet if it don't let ya down, just when ya need it the most....read the book. if it aint a mercruiser book, get one. it'll tell ya exactly what ya need to inspect for and do.....there's much info in them......it really is the best place to start to learn about what yer trying to do......