Jump to content

Recommended Posts

So now that I'm a new boat owner, I was thinking it would be a good idea to take it in to get a full tune up for the outboard (115hp merc, oil injected).  Then I poked around on the internet and am seeing estimates of about 1/6th of what I paid for the whole boat and motor. Yikes.

 

Do you guys do your own tune ups? I'm not a motorhead but am fairly handy and can follow instructions.

Share this post


Link to post
Share on other sites

Do yourself a favor - allow a professional to set that 31 year old motor up for success.

 The initial expense of parts & labor will FAR Out weigh the lack of frustration and time lost on the water when compared to 'saving a few bucks' by doing it yourself.

Unless you've spent the last 40 years it took to get your rig working on these motors, I recommend leaving it to someone who has.

Good Luck.

A-Jay

  • Like 3
  • Thanks 2

Share this post


Link to post
Share on other sites

Good advice 

  • Like 1

Share this post


Link to post
Share on other sites

Yeah, I'm kinda thinking the same thing.

  • Like 1

Share this post


Link to post
Share on other sites

If you had my 60 years of experience working on motors, nothing to it. 

Without that, If it needs anything more than a new set of spark plugs, trying to do it yourself could get very expensive.

  • Like 1

Share this post


Link to post
Share on other sites

Can you tell me what, typically, a tune up entails?  Thanks.

  • Haha 1

Share this post


Link to post
Share on other sites

You don't really give much to go on, other than it's an older 115 merc with oil injection.  If I were to guess, it's probably the late 80's, I6 tower of power.  Those are nice motors, if it quits, just turning sideways into the wind and use if for a sail. 

As for a tune up, a lot depends on how it's running now.  If it's running great, a set of plugs might be all it needs.

If you are having intermittent problems with it running rough, misfiring, and bogging down coming out of the hole etc, then it's gonna have to go to the doctor.  You could be looking at carbs cleaned, ignition parts, a stator, plug wires, and probably due for a water pump. Basically, a whole bunch of money.

The first thing it needs is a compression test or leak down test.  If the compression isn't where it should be, it's not worth spending the money for all that other stuff. 

I would say you could probably do the compression check yourself, but if it is one of the I6's, doing that bottom cylinder sometimes requires dropping the lower cowling.  It can be a royal pain to do.

Share this post


Link to post
Share on other sites

Way2slow hit many of the top items as he always does. If it is running great, I would still consider adding other items to your list, including things like a fuel pump diagram (most just replace the entire small pump) because you have no idea when it was last serviced and today's fuels are hard on them, or should I say they tend to get hard because of the ethanol in most of today's fuels.  Next I would replace its fuel filter, if it has one. I do not remember since the last one of these engines I owned I sold at least 25 years ago. I would definitely replace the fuel lines from the tank to the engine. The newer fuels eat the older lines from the inside and release tiny fuel line bits downstream to the engine. Get this directly from the dealer, they come in bulk and you buy so many feet as needed. I will say this about my old 115, it ran great and was super reliable but tougher on gas mileage.  Again, you have no idea when any of the small fuel lines or spark plug wires were changed and they are old and can get brittle. I would inspect them carefully. I would have a water pump replaced no matter what, and this will lead to replacement of the old lower unit oil as well. Many of the items Way2slow and I have mentioned would not be on my annual maintenance schedule, but I did almost every one and a few others when I repowered my 6 year old Lowe bassboat boat with a used 2003 Mercury 75 Hp outboard. I even replaced the anodes on the lower unit because they were partially eaten. I had seals replaced in the tilt assembly. The pump was good, but you could see the pump seals were starting to seep fluid. I did all these things so my perfectly good running used motor would be up to snuff and it has been almost flawless ever since. That was more  than 7 years ago.  I do not have the professional outboard experience that Way2slow does, but I turned wrenches an construction equipment, diesel engines up to 1000 hP, generators, traines, cranes, and nuclear waste moving equipment LOL. 

 

I observed one constant during all of that. which spanned almost 35 years and this is it. Here it is, performing routine

maintenance ahead of time is much cheaper than repairing the failure later! Just my 2 cents.

Share this post


Link to post
Share on other sites
16 hours ago, billmac said:

Can you tell me what, typically, a tune up entails?  Thanks.

To me....changing spark plugs, and basic maint. is NOT a tune up. Although, those things can be part of a tune up.

 

As soon as gauges, consulting service manuals, using tools I don't own, and fiddling with parts of the fuel and or ignition system comes into play....then it's a tune up, and I pay to have it done.

 

I change plugs/filters/fluids myself.

Share this post


Link to post
Share on other sites

It is indeed an I6.  Is there a way to look up the exact vintage by using the serial number?

The water pump was replaced last year.

Share this post


Link to post
Share on other sites

Here's my fear.  Because I don't know what I don't know, I see myself taking it in and having the guy tell me I need $3000 worth of parts.  Maybe I've had too much experience with car mechanics.  I'm poking around now to find a marina or dealer who can work on it.

Share this post


Link to post
Share on other sites

I am far from a motorhead but carb cleaning, new spark plugs, water pump replacement, and lower unit service can all be done by an average dude with a set of wrenches and a little patience.  

 

I guess it boils down to how much spare cash you have, but I've never had the burden of making that decision.

 

YouTube can guide you through servicing most outboard motors.  No, seriously 

Share this post


Link to post
Share on other sites

How does it run now still needs to answered before jumping off the deep end.

Inline Merc 6's are a very reliable engines with a few exceptions. I don't recall what model year had issues, but you can look that up. 1988 was the last year the 115 inline 6 was made.

You basically have 3 carbs, 1 for for each set of 2 cylinders. 

As Way2Soow suggested start with a compression test. After removing the spark plugs look at each plug closely to deterime how it's been running, lean is light brown, rich is black, oily is poorly. This tells you where to start looking for problems if they exist. .

Compressions checks OK, plugs look the same brown color for all 6 cylinders, you may be good to go with simple maintenance.

Tom

Share this post


Link to post
Share on other sites

The serial number is what you have to use to determine year model.  The S\n sequence number falls within a certain year.  You might be able to find that online or call a dealer and have them look it up.

Since I know enough about motors to do any and everything on one, I'm the worlds worse about periodic routine maintenance.  12 month LU lube change and water pumps every three to four years are about the only things I do.  I just replaced the fuel filter after at least seven year, but I do keep a spare in the boat, just in case.  I have two sets of spark plugs and haven't installed new spark plugs in years.  Every spring, I pull the ones in the motor out, and put the spare set in.  Then I clean, gap and inspect the set I took out and store them in the boat, in case I need one.  Ficht motors are prone to foul plugs if idled for long periods, even with them indexed. 

 

I hate to say this, but as a non mechanic, trying to rebuild and adjust the carbs on that motor is not something you can do, they are not and easy set to rebuild or adjust.  Especially, with most labor rates in excess of $100 per hour and much of the work on that motor is labor intensive.  With todays overhead cost, most dealers inflate parts prices well above recommended retail, and labor hours are usually padded.  Like going to a shop and they quote out of a flat rate manual, when an experienced mechanics can do the job in half the time allotted.

Your fear of getting ripped off if a valid concern.  I've worked as a mobile lift truck service tech for almost 20 years until I retired and during that time, knew one truly honest mechanic and no honest dealer ships.  Mater of fact, the reason I finally retired, the company I was working for was on to do a number of things that were just down right crocked to increase billings and refused.  Then they started demanding I start doing some of these, things.  Being retired from 22 years of military, over 65 years old and eligible for almost max social security, I decided it was time to call it quits.  I had lived that long without having to screw over people, wasn't going to start then.

  • Like 1

Share this post


Link to post
Share on other sites

I've gotten 1 quote back of $200 for the tune up if nothing is wrong.  I was pointed to a dealership by one of the other marinas and my radar went off.  I haven't had good experiences with dealerships. $$$

Share this post


Link to post
Share on other sites

$200!!.  That might cover labor and parts for a compression test and new set of spark plugs.  There is hardly no way that old of a motor is going into a shop that's worth a darn for a tune up and they don't find anything wrong with it. 

 

Like I said, it boils down to why you think you need a tune up.  If the motor is running great, and you just feel it's time to give it a tune up.  Do a compression check and put a set of plugs in it yourself.  Both of those are things almost anyone that know which direction to turn a wrench can do.

 

If it's having issue's when running, just does not run right.  That's a lot more involved and no way on gods green earth are you going to put it in a shop and get it back out for $200.  Closer to $700 -  $1,000 would be a more realistic number.  Just to do the carbs could run $350 or more.  There are several ignition parts that can cause problems, and those can run in the hundreds.  Then the labor involved in working out the problems can be a few hours.

 

I will say, anything beyond replacing the plugs and doing a compression test yourself, you will most likely screw it up and then have to pay the shop even more to fix what you screwed up, I've had to go behind a whole load of those kinds of repairs, and in almost every case, it would have been a helavalot cheaper if they had called me first.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for all the advice.  I will start with the compression test and new plugs and go from there

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

  • fishing forum

    fishing

    fishing forum

    fishing rods

    fishing poles

    fishing

    fishing reels

    fishing poles

    fishing reels

    fishing

    fishing

    bass fish

    fish for bass
    fish

×