Merc I/O 4cyl 170HP advise

[jpv]

I just bought a 1985 Wellcraft 190 American....I was browsing this forum and found what I think is a lot of negative info on my engine...

I dont know a whole lot about it but I will try to give you some clues.....

It is a merc cruiser 170 HP 4 cyl I/O with a antifreeze cooling system...and I see no belts running an alternator. It looks very basic to work on.......but one of the threads had info about several problems on this or a similar engine....I hope its not mine....the thread mentioned a 470 3.7 liter????/ I cant confirm that is what I have...if I knew how to post a picture I would.
Please let me know if I have a reliable work horse or a high maintenance problem.

Thanks

 

[CheapboatKev]

Re: Merc I/O 4cyl 170HP advise

Sorry to say...but you indeed have the nightmare motor..


Is it running properly? Are you having any issues with it?

Also..Welcome Aboard...

 

[Bt Doctur]

Re: Merc I/O 4cyl 170HP advise

As long as you never overheat it or try to charge a weak/dead battery connected to the boats charging system.

 

[Don S]

Re: Merc I/O 4cyl 170HP advise

Please let me know if I have a reliable work horse or a high maintenance problem.

The answer to your question is YES.
It will be a reliable work horse as long as everything on it keeps working, and Yes, it will be a maintence problem if it doesn't.

the thread mentioned a 470 3.7 liter????/ I cant confirm that is what I have...

Any 170 hp 4 cylinder Mercruiser from 85 is a 470/3.7L motor.

Go up to the Adults Only sticky at the top of this forum and download the OEM service manual #8. It has all the pictures you will need to ID the engine.

 

[stonyloam]

Re: Merc I/O 4cyl 170HP advise

Please let me know if I have a reliable work horse or a high maintenance problem.

I am assuming that it is running and sounds OK, or you wouldn't have bought it right? You should probably do a couple of things right off the bat to asses the engine health (remember it is 20+ years old). First a compression check, and if all of the cylinders are close to the same compression (somewhere in the 120-140 psi range). If any one is low (especially 3 or 4) a new head gasket and valve job over the winter might be in order. Next check for any coolant leakage (while running) from little weep hole on the lower starboard side of the coolant circulating pump on the front of the engine, if leaking you will need new cam seals. finally check to make sure that the alternator is charging properly (13+ volts), if it is don't worry about it till it fails, then replace it with an alternator kit. Good luck, welcome to club 3.7!

 

[jpv]

Re: Merc I/O 4cyl 170HP advise

Dog gone! It looked so simple and purred like a kitten when the previous owner showed it to me. I have only seen it run for 5 minutes out of the water on muffs. I only paid 2k for the rig and the engine and outdrive have just been rebuilt. My next question is.....is this engine so unreliable or problematic that I should just sell this rig for what I bought it for and move on? Give it to me straight....I can take it.

Thanks

 

[Bondo]

Re: Merc I/O 4cyl 170HP advise

is this engine so unreliable or problematic that I should just sell this rig for what I bought it for and move on? Give it to me straight....I can take it.

Ayuh,... I would.... Then buy another 1 with a Chevy based powerplant...

 

[TilliamWe]

Re: Merc I/O 4cyl 170HP advise

At this point, since you already spent $2000 on the boat, I would use it. As long as it's working properly, go boating! And download that manual and maintain it properly too.
Just be prepared that when the charging system breaks, or the antifreeze starts leaking, it'll cost $$$$$ to repair. Or if the exhaust manifold and elbow fail, and #4 cyl starts filling with water, you could bend pushrods, valves, connecting rod. Again big $$$$$. So basically, be prepared to lose all your $2000 initial investment.
But in the meantime, GO Boating!

 

[ErieRon]

Re: Merc I/O 4cyl 170HP advise

On a brighter note...

I have a 1984 470 that I bought new and it has been a very reliable, economical engine. Mine is in a 23' cuddy (3800 lbs) and runs around 38-42 mph, cruises at 25-28 mph, and is great on fuel. From day one, I maintained it as one should and have only had minor repairs to deal with, all maintenance related (gaskets, carb rebuilds etc).

Just this season the front water seal began dripping. So, over the winter I will remove the engine and perform all of the inspection, replacement & upgrades and put it back in.

In my case, it's well worth the money, but I know the history. In your case, I would do as Stonyloam suggested and do some proactive maintenance and inspection.

You may be very pleased if the previous owner had it rebuilt properly. Can you get any details on the rebuild? May be very helpful in your decision process.

 

[jpv]

Re: Merc I/O 4cyl 170HP advise

Thanks guys. Its not too late for me to get out and not lose my investment. I am not handy enough to comfortably do the engine maintenance that this engine will need down the road....and I dont see me pulling an engine out. I am shocked that a simple looking I/O could be so problematic! I recently looked at a 1999 Mariah that had what looked like the exact same engine.....are they still making this beast? Or is this the new bullet proof version? I will clean up the boat this winter real good and sell in the spring to someone ready for the task The advice that you get on this site is priceless......and thanks for welcoming me aboard.

JPV

 

[stonyloam]

Re: Merc I/O 4cyl 170HP advise

...the engine and outdrive have just been rebuilt.....

Thanks

That engine probably went 20 years before being rebuilt. If it was properly rebuilt there is no reason that it could not go another 20 years (mine is 22 years old with only a valve job). If it sounds good on the muffs and runs smooth it is probably just fine. A lot of guys who's opinion I respect, really don't like those engines, but with proper maintenance you should be OK. Just stay calm, and don't panic. As far as the chevy engines, they are not perfect ( to see how many folks have gotten hosed....), just type in "cracked block" in search and look at some BIG$$$$ problems with those. Learn how to properly maintain it, use it and enjoy it.

 

[zbnutcase]

Re: Merc I/O 4cyl 170HP advise

They have proven to be a decent engine. In 23+yrs in the biz, I have rebuilt a whopping TWO,(1 because owner left boat out in rain with spark plugs out-not engines fault) never done a head gasket job, replaced cam seals maybe a dozen times max. However, I have replaced more stators and regulators than I care to think about...'nutcase

 

[nrob84]

Re: Merc I/O 4cyl 170HP advise

hey!! i just bought an 87 192 classic with the same motor!! i to got alittle nervous about the motor when i looked around on here. but believe it or not after checking everything over and some minor repairs ive been out a few times on it and i like the motor. little noisey but very fast for what it is. my handheld gps will read 45 - 47 on the ocean on a calmer day. check your compression, if thats ok, and no coolant or water in the oil, you should be good to go. prolly wanna look into that alt conv kit. and make sure you have the 4 inch heat exchanger!! if not look into getting one. but long story short i love my boat. just keep up on maint. and im sure youll love yours 2

 

[Bondo]

Re: Merc I/O 4cyl 170HP advise

I recently looked at a 1999 Mariah that had what looked like the exact same engine.....are they still making this beast? Or is this the new bullet proof version?

Ayuh,... You weren't Lookin' close enough....
These motors went Out of production nearly 20 years ago,+ they were only made for a few years at that....
Many of the replacement parts now have the part # NLA....

The 99 is No doubt a Chevy based motor,.... Much different than the 470s...

 

[jpv]

Re: Merc I/O 4cyl 170HP advise

Ok....so I have some options.....it aint all bad......I called the previous owner today to get more details about what was done regarding the rebuild. He is very confident in the engine and outdrive...and I think it is rare when a previous owner is happy to take calls. The engine has been completely rebuilt...the valves have been adjusted....it has a 4" heat exchanger and the previous owner says it never ran hot or overheated. It does however have a stator...which I have never seen or even heard of until i bought this engine. Why does the stator fail? What happens when it fails? Dead battery...? How much will it cost to have a local side job mechanic install an alternator kit? I assume that if I have a 4" heat exchanger, and an alternator kit....I am close to being on the right track.

On the other side of the coin.....how much is my rebuilt 4cyl 470 170 HP worth..it only has 15 hours on it?

Maybe I could do an engine swap with someone...I am assuming that there are several engines that will match up with my outdrive.

Thanks again guys

 

[ziggy]

Re: Merc I/O 4cyl 170HP advise

this may be an interesting read for you...
http://www.sterndrives.com/470information/470coolantleakrepair.html

 

[stonyloam]

Re: Merc I/O 4cyl 170HP advise

Why does the stator fail? What happens when it fails? Dead battery...? How much will it cost to have a local side job mechanic install an alternator kit?

On the other side of the coin.....how much is my rebuilt 4cyl 470 170 HP worth..it only has 15 hours on it?

Maybe I could do an engine swap with someone...I am assuming that there are several engines that will match up with my outdrive.

Thanks again guys

OK first off FORGET the swap, just not worth it!

Second, DON'T WORRY ABOUT IT!!! That is a fine little engine, and with 15 hours on it it will give you YEARS of service.

As far as the stator goes. If it is currently working, again DON'T WORRY ABOUT IT, till it fails. The stator works kind of like an alternator, and a couple of things can go wrong with. The magnets can work loose and cause the stator itself to fail, or much more likely,the water cooled voltage regulator can fail ($$$$). If either should happen the voltage meter will show 12 volts or less (as opposed to 13+v) and then you can get an alternator kit from someone like Breezeworks. Any competent mechanic should be able to install it in an hour or so.

Take it out in the spring and try it, you'll like it! If you decide to sell it, someone will get a nice little boat.

 

[jpv]

Re: Merc I/O 4cyl 170HP advise

ya....Im gonna keep the ole girl.....I like the boat, she has good lines and lots of personality. The engine will be a keeper as well....You have answered most of my questions...buuuuuuuuut.....this water cooled regulater...sounds like I better get a better understanding of that bad boy.....You say if it fails $$$$$$$$$$$ How much $$$$$$ ??????? Will an alternator kit use this same regulator or render it obsolete? It seems like I can get an alternator kit for $500 retail maybe much better if I know someone.......so maybe kit and install for $500......would this solve the stator and the regulator issue?.....If so...all I have to deal with is some weaping antifreeze, and an engine made out of aluminum and cast iron.....right?

Thanks

 

[Don S]

Re: Merc I/O 4cyl 170HP advise

The good news. You are going into this boat with your eyes wide open.
You know the possibilities.
Yes, the alternator kits will eliminate the water cooled regulator, stator and all.
The cam seal is something to keep an eye on, do maintenance per the manual, keep the cooling system working. change the impeller often and have fun with it.
Up in the Adults Only sticky at the top of this forum is free downloadable oem service manuals for your engine and drive .............. Get them NOW.

 

[ErieRon]

Re: Merc I/O 4cyl 170HP advise

I think you've made a good decision, and as Don points out, you are now aware of what to do and what to monitor closely. That voltage regulator will be around $500.00 to replace when it goes.

You can get the alternator kit at breezeworks for $289-299.00. It includes the bracket (high mount or low) and the wiring harness. Here's the link; http://www.breezeworks.net/

Removing the alt/stator components from your engine to install the new regulator happens to be the first steps when repairing the front water seals. Just pointing it out. It may be worthwhile to do it all at the same time.

You can download your manual here; http://www.4shared.com/account/file/121929231/58a54283/MercruiserManual8.html