mercruiser 470 and Alpha 1 outdrive (few problems)

[searay79]

hello everyone.

i purchased my first ocean boat 2 months ago. it seems there's a few more problems than what was originally expected. i'm by no means a mechanic, so i'll do my best to describe the problems and what i've been told thus far. any feedback you guys could provide would be most helpful.

boat details:
79 searay 19ft
470 mercruiser motor
alpha 1 outdrive

problems:

1. trim pump does not raise and lower outdrive.
-note*: was told by original owner that it was most likely a gasket. was told by a marina that it might only be the o-rings
-attempted solution tried : unlocked the back pistons? (things that go in and out). tightened the bolts of the trim pump (they were lose) and the drive was able to go up and down. 2 weeks later some oil was spraying out and it doesn't move.
questions: how can i tell if its just a gasket or o-rings and not a bad pump that needs replacement?

2. motor stalls out
-attempted solution tried: spraying carb cleaner in top while running.
-note*: friend (who is more mechanically inclined that i) said he saw the one barrel dripping fuel, then spraying fuel on and off. also the choke assembly is broken and we had it zip tied on as a temp fix. i was able to get it to start w/out starter fluid when playing with the choke setting.
questions: does this carb need to be rebuilt? can i take any other steps that can eliminate it as a potential problem before i spend the money to rebuild or replace it?

3. motor overheats (the big issue)
-details: as i was trying to get the motor to run, i noticed the temp raised pretty high (right before the red). i heard crackling similar to leaves burning in a fire after the engine was turned off. my friend seems to think it was the oil that squired from the trim pump that was burning off the engine. we noticed a few things:

1. the oil was milky. we did an oil change before in which it was still a little milky but assumed that maybe it would just have to be flushed out with another oil change.
2. the antifreeze was jelled up. when we took out some antifreeze we noticed it was jelly on the bottom. the old owner thought maybe it could "break up" as the engine heated. (i'm no mechanic but this doesn't seem logical at all to me)
3. the exhaust "something" has a crack in it. were the exhaust goes out theres a slight crack in the platic piece. i do not know the name off the top of my head.

solutions to attempt: we want to flush out the system to get all the jelly antifreeze out, then replace with new.

questions: what steps would you guys recommend i take? some people say it sounds like a blown head gasket. from another post i obtained the following:

Everyone loves to reply "head gasket" but you should know thay 99 times out of a hundred water in oil is caused by BAD exhaust.You should check risers and manifolds if your "condensation" doesn't go away. I just fixed the same problem myself and not 1 out of 250 people I asked told me to check my exhaust.Check for water in your dry exhaust ports!!!!!!!!!!

i wonder if the milky oil is cause by "bad exhaust" from the cracked plastic piece (the exhaust "something" i mentioned above)

i know i practically wrote a novel, but any helpful info you guys could share would be great. i'm hoping i can luck out here with the problems turning out to be smaller than i'm fearful of.

thanks in advance!

searay79

 

[Fishermark]

Re: mercruiser 470 and Alpha 1 outdrive (few problems)

First... welcome.

Second... that's too many questions in one post! Most people's eyes will glaze over reading it all and will not know where to begin to answer. I would suggest making a new post with only one question / problem. Sorry I cannot be more help on the specifics.

 

[HT32BSX115]

Re: mercruiser 470 and Alpha 1 outdrive (few problems)

Howdy,


Well get ready.....you'll see a lot of replies that will say: #1 problem.....470 engine!
(sorry)

The first 2 problems are not big deals (easy to fix generally) the last problem is a big deal. Aluminum block and cast iron Ford 460 head come to mind.....

It could be a riser gasket or a few other 470 related problems. Do a search before you go much further for "470 problem" etc. Also there's a lot of info on the net about the 470.

i'm by no means a mechanic, so i'll do my best to describe the problems and what i've been told thus far.

If you cannot do any of the work yourself , you should still probably get yourself a Mercruiser service manual so you can be somewhat knowledgeable when you take it to someone that IS able to do your work.

I won't sugar coat it. It won't be cheap. Mercruiser stopped making the the "470" shortly after introducing it for a reason...


Regards,


Rick

 

[bhammer]

Re: mercruiser 470 and Alpha 1 outdrive (few problems)

Welcome to iBoats.

1. there are both gaskets and a couple O-rings. Depending on where it is leaking from would depend on where the fix is. I'd start by trying to find a gasket kit for that pump and re-gasket it.

2. There are many issues to check before you start rebuilding the carb. I would suggest that you post that as a seperate question and let the pros have at it. Fuel supply, water in fuel, tune-up all come to mind.

3. I would focus on this long before I even looked at 1 or 2. The 470 engine is a closed cooled engine and requires water / antifreeze to be circulated around and a heat exchanger (big cylinder on port side) acts like a radiator using the sea water. Was the engine properly service with antifreeze and water before running?

As for water in the oil, there are many places it could have come from. Likley place are the head gasket, manifolds and the water pump shaft if someone plugged the drain hole on the bottom of the timing cover.

I think you need to start with a pressure test to try and find where the water is coming form.

Getting these engines hot is a real BAD thing and kills them quick. Do you know how hot you got? Did you blister any of the paint on the engine?

 

[searay79]

Re: mercruiser 470 and Alpha 1 outdrive (few problems)

thanks for the replies guys. i didnt meant to post a hole huge novel about it, but i figured i would share all the info in case they were linked together. i will make seperate posts once i diagnose better.

i just got off the phone with my buddy who took a look at it. according to him there was some metal (rush like pieces) that came out from the water pump. he seems to think its the manifold. if not that the head gasket (possibly both).s

as mentioned above, it seems we are going to try and pressure test it. don't i need a special gauge for this?

also, once i determine where there is a leak...how do i determine if its the manifold or the head gasket?

lastly, anybody who's in the market know how much some of the costs would be?

manifold (new or used but in good condition)
head gasket (new or used in good cond.)
labor to replace both if i pay a mechanic

(i checked ebay but it doesnt seem to have these parts listed)

thanks again!

 

[bhammer]

Re: mercruiser 470 and Alpha 1 outdrive (few problems)

You can pick up the gauge to pressure test from your local autoparts store. It is just a standard radiator pressure tester. Your radiator is the heat exchanger and the fluid is held in the rectangle box on top of the engine and the overflow coolant container on the startboard side down low.

You need to buy a manual for the engine before you go too far. It is one of the better investments you will make.

Check out the below link for some info on the waterpump seals. If you tear into it, you will want to do the fix.

I can't help you on the costs, but it's all availabel on-line, just do a search for merc 470 parts. I have bought some from iBoats and a couple others.



http://www.sterndriveshop.com/470information/470coolantleakrepair.html