Advice please on D115 OBs

[CaptainJayMoore]

Newby here...never owned an OB...looking at Rosborough 24' with twin 2003 D115 OBs with 1,500 hours...plan to have them surveyed by certified dealer...anyone know of any issues I should look for? When I get the service records on the motors, what service intervals and tasks should I look for?
Thanks

[Harper]

The dealer who does the survey should be able to tell you about the service intervals, and what is done at each service. It's a bit wordy to post it all here, but basically, after the initial break-in service, the motor is serviced at 100 hour intervals, more often if not used regularly (for instance, I've had my DF150 for 6 years, it has only 250 hours on it, so I service more by the calendar than by the engine hours). Services mostly involve changing the oil and filter, gear lube, greasing the swivel and steering brackets, and various other things like throttle linkage. Other things,like sparkplugs and valve lash are checked and adjusted/replaced less often. Some of the DF140s and DF115s up to a certain year had a problem with corrosion of a plug in the engine holder. I don't know if the 2003 model DF115 was affected by this problem or not. Someone else will hopefully address that for you.

[Moonlighter]

Mike is correct.

Whoever surveys the boat for you, make sure they have access to the Suzuki SDS diagnostic computer system.

This allows the technician to connect their laptop to the 4 stroke outboard's ECU and download a whole heap of very important information about the engines performance, any alarm codes, servicing, other errors as well as the rev ranges it has operated at over its lifetime. You would definitely want to get a printout of this download for both engines and have it reviewed by a competent Suzuki technician to see if there were any concerns.

Mike is also correct in that some of the early DF115's, including the years you are looking at, potentially have a problem with corrosion in the engine holder. There is basically a steel welsh plug on the port side of the engine just near the place where the fresh water flushing attachment is. Because it's a steel plug inserted into an alloy engine block, and is subjected to lots of exhaust heat from inside the engine, dissimilar metal corrosion can happen and develop a hole thru or beside the plug.

So definitely check for any signs of that, and see if the plugs have already been replaced by the owner with alloy ones, or have been removed and welded over.
If that hasn't been done, and you go ahead with the purchase, I would factor the cost of having them replaced or welded over - not expensive, say allow $250 per engine.

[CaptainJayMoore]

2003 D115 OBs

Many thanks for the insightful info...will follow-up with surveying tech...
Does 1,500 hrs. seem like a lot on these engines?
In the diesel world where I have been in last two boats, engines ran for 10K hrs before "major".

[Moonlighter]

You will probably get varying replies to that question of hours, Capt!

For outboards, the issue tends, in my opinion, to be more about age and maintenance than about hours.

For example, outboards, especially these 4 strokes, that are used by professional guides, towing organisations,pro fishers etc, it is nothing to run up a couple of thousand hours per year and run reliably for 7-8000 hours over a short time of 3 or so years. And still be in good condition after that. These operators rely on their engines for a living so they maintain and service them properly and on schedule all the time. My local Zuke dealer has seen pro fishermen with Suzukis with over 10000 hours in them and still running strong.

Whereas a recreational angler might only do 40-50 hours per year. And may or may not complete the maintenance regime required to keep them in good condition. Corrosion and time go hand in hand, and need good a maintenance focus to stay on top of.

The question also arises of whether they have been predominantly salt water or fresh water engines. Salt water is a harsher environment and means things like internal anodes need regular checking and replacement, as well as greater attention to flushing, washing down and general care and attention. Life will also be affected by whether the boat was trailered and garaged, or left on a mooring, or outside on a trailer in the weather. Lots of factors.

The 2003 engines you are looking at are now 12 years old. Average of 125 hours per year, which means they have been used quite regularly - probably at the upper end of the scale for many recreational users, depending of course on the area they have been used in and distances to fishing grounds.

If they've been well maintained and you can see proof of that, then they've probably got quite a few more good years left in them - depending on how you use them of course and how they are maintained from now on.

One last thing to mention: these Suzuki 4 strokes, and indeed all outboards, really do not like "lugging".

The critical element in this equation is the propellor, and to prevent lugging, the engine needs to be fitted with a propellor that will allow it to reach the upper end of its recommended rev range at full throttle (WOT). Some people mistakenly choose a prop that keeps revs down at cruise speed, but that is like driving a car around town all the time in top gear - it will be lugging and this will increase wear and reduce engine life. Badly. And it will be less economical as well. We refer to that as being "over-propped" - a propellor with too much pitch.

So i would want my surveyor to do a sea trial and give it a solid burst of full throttle, trimmed out, and ensure that the engines will both reach at least 6000rpm or very close to that. Anything less than 5700, and I would be walking away - because as soon as any extra load is on board (people and gear), revs would then drop lower and you would definitely be lugging the engine.

The engine printout you get will also show the number of hours the engine has spent at each 1000 rpm range. If that data showed no time spent, or almost none, between 5000-6000rpm and none at all above 6000rpm, I would walk away - this is a sign of an engine that is over-propped and has been lugging most of its life.