How many engine hours is too many on a used boat to get another 5 years out?

[smokedvw]

Hi,

I have always been curious how many hours is too many on a used engine to actually get at least 5 years out of it? Most boats I see that are "low" hours are somewhere around 200ish. I see lots of boats in the 700 range as well which seem to be priced lower. I know on my current engine I have used it many times our prawning and ran the engine the entire time we are out there 2-3 hours a trip so the hours can add up.

I think currently I probably put on 50-100 hours a year on my current 50hp 4 stroke Mercury and have just been doing normal maintenance. I am just curious how many hours you can expect out of a Yamaha 4 stroke or any 4 stroke in the 90-140 range.

Thank you

 

[ExFlyGuy]

I've seen some 90hp yamis that run wide open all the time with 3000-4000 hours these engines run every day all summer though. I would think 1500 -2000 hours should be easily achieved with any modern 4 stroke engine in that size.

 

[scott craven]

I got over 3000 on my Honda before the gear case split.
motor was still running strong.

 

[Klob]

A low hour engine not maintained properly will probably not last as long as a high hour motor that has been looked after. It all comes down to the previous owner.

 

[smokedvw]

A low hour engine not maintained properly will probably not last as long as a high hour motor that has been looked after. It all comes down to the previous owner.

Yeah and that's always a issue to determine I find in any used car or boat purchase. Some people are very meticulous and keep all records others have no idea.

 

[Clint r]

Know someone who had a 2014 90hp yamaha with over 3000 hours. Tech at yamaha who did the scan said he’d seen more than one at 7000hrs and still going strong.

 

[Fishin]

2000hours on my 04 Yamaha 115 4 stroke still running fairly well but is definitely getting tired and will need replacement in the next year or so.

 

[sparrow139]

2200 on my 2008 yamaha 250 and still going...

 

[ryanb]

I'd say 3000 hours is a good benchmark, give the engine 100 hours for every year old, so a 20 year old engine with 1000 hours or a 10 year old engine with 2000 hours is getting close to end of life. Of course there are exceptions, well maintained 3 year old engines with 500 hours have been known to go kaboom on occasion and some last 30 years and 7000 hours. Nothing in life is certain.

 

[gungadin]

Maintenance is imo the key. Oils and filter changes, zinc changes (external and internal) flushing after use in the salt water, replacement of water pump innards, spark plug replacement etc. I believe a good mirror of how well the engine has been maintained is how clean the engine is under the cowl. Look for green corrosion on nuts and bolts as well as around gasket areas, Any of which would be an orange or perhaps red flag for me.

 

[smokedvw]

Maintenance is imo the key. Oils and filter changes, zinc changes (external and internal) flushing after use in the salt water, replacement of water pump innards, spark plug replacement etc. I believe a good mirror of how well the engine has been maintained is how clean the engine is under the cowl. Look for green corrosion on nuts and bolts as well as around gasket areas, Any of which would be an orange or perhaps red flag for me.

Do you leave your boat moored? I find I have green corrosion in a few spots that even though I maintained the engine regularly leaving it moored for 6 months (and flushing each time) still gets salt under that cowl.

 

[scott craven]

Salt under the cowl ? check thermostat and housing to make
sure they aren't leaking

 

[gungadin]

I think salt can get into the motor area under the cowl in several ways. If the air intake is at the front of the engine-salt water spray when travelling, if the intake is at the back of the engine, a vortex can pull water into the cowl. Some boats have a tendency to have water climb up past the cowl seal when stopping quickly, or when not moving quickly forward in a following sea or in standing waves, the same applies if back trolling to maintain your position in a moving tide. There are drain holes in the bottom section of the cowling that could admit water as well. Take your cowl off and move your finger in different places along the inside of the cowling (top and bottom), you should be able to see the line your finger makes if there is any salt on the cowling. If you feel the need you could taste any residue on your finger.
At the same time any green or obvious build up on the outside of a joint that is sealed with a gasket indicates that the gasket may saturated with salt (dried perhaps) and dried salt certainly attracts water. This can occur from salt laden moisture in the atmosphere under the cowl or of course as Scott points out an internal leak, however small.
Occasionally spraying the engine area under the cowl with WD 40 or other moisture repelling fluid will help in preventing this buildup from external sources, but not from internal leaks.

 

[sly_karma]

Simple age in years is also a factor. A 2002 model year unit with low hours still has gaskets, seals and hoses that are two decades old. 20 hours a season with perhaps a couple years of no hours at all isn't necessarily a great motor. You'd be well advised to change out all fuel lines and filters inside the cowling just to be sure they're not breaking down with all those accumulated years of inactivity. Clogged/dirty injectors a near certainty.