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2015 Yamaha 242 - Engine life - How many hours?

Messages
25
Ratings
14
Points
3
Location
Krabi, Thailand
Boat Make
Yamaha
Year
2018
Boat Model
242 Limited S E-Series
Boat Length
24
#1
Assuming a boat is run in correctly, cared for and serviced appropriately and didn't spend it's whole life with the throttle wide open, all day... how many hours before one is looking at rebuilding the engines in a 2015 Yamaha 242 Limited S?
 

boudin

Well-Known Member
Messages
312
Ratings
230 8
Points
58
Location
Lake Livingston, Texas
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
21
#2
My guess would be well over 1000, maybe 2000+. The non-HO MR1s in VX110 rental skis see those kinds of numbers. I would not consider a rebuild until you start seeing significant oil burn, and/or greatly reduced RPM.

Do regular maintenance, and check the service manual to see when things like timing chain, tensioner, valve adjustments, etc. should be done.

-Greg
 

112Vulcan

Active Member
Messages
92
Ratings
50
Points
28
Location
Cape Coral, FL.
Boat Make
SeaRay
Year
2005
Boat Model
Other
Boat Length
29
#3
My guess would be well over 1000, maybe 2000+. The non-HO MR1s in VX110 rental skis see those kinds of numbers. I would not consider a rebuild until you start seeing significant oil burn, and/or greatly reduced RPM.

Do regular maintenance, and check the service manual to see when things like timing chain, tensioner, valve adjustments, etc. should be done.

-Greg
Does anyone know what the motor replacment, timing chain, valve adjustment runs ($$$) ?
 

swatski

Jetboaters Fleet Admiral
Messages
8,789
Ratings
9,441 138
Points
493
Location
Saint Louis, MO
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#4
Yamaha boat engines are second to none. Keep in mind, unlike cars and trucks, marine engines are designed for "continuous duty" and can be run WOT all the time. Those Yamaha 1.8 and MR-1 engines are raw water cooled and maintain perfect operating temps at WOT as the cooling system works at its best.

I have known several commercial fishing operators in NE, they tend to run their o/b fleets approx 2,000+ hours, all WOT, and that's the "norm". Then re-power. If you worry about longevity - it's the maintenance and how the engines are used that's most important. I would take a well maintained high-hours all WOT yammie over one that's low hours but sitting around and possibly neglected, especially if used in salt water.

--
 

Scottintexas

Jetboaters Captain
Staff member
Messages
3,155
Ratings
2,124 43
Points
243
Location
Corinth, TX (DFW)
Boat Make
Yamaha
Year
2007
Boat Model
AR
Boat Length
23
#5
welcome aboard Krabi!

as the others stated, it's a long ways out if even just the most basic of oil changes/flushing is done,

I also take solace in knowing the engines are in jet skis which are asked to do much more extreme rpm's swings and run harder than the boats
 
Messages
3,270
Ratings
2,994 93
Points
268
Location
Florida
Boat Make
Yamaha
Year
2014
Boat Model
Other
Boat Length
Other
#6
I love the 1800 engines I have had supercharged and regular engines I do oil and filter every 50 hours plugs once a year average well over 150 hours a year, only had one timing chain fail on one at around 350 hours and Yamaha repaired it. There are some minor issues that usually require some attention as well as things to avoid or watch out for like anything mechanical but for the most part very reliable engines and pumps.
 

AZ Native

Jet Boat Lover
Messages
191
Ratings
205 7
Points
83
Location
Phoenix, Arizona 85044
Boat Make
Yamaha
Year
2013
Boat Model
Limited S
Boat Length
24
#7
Those Yamaha 1.8 and MR-1 engines are raw water cooled and maintain perfect operating temps at WOT as the cooling system works at its best.
--
I do oil and filter every 50 hours plugs once a year average well over 150 hours a year,
I've meant to ask why we are changing the plugs so often? Is it because the engines don't get hot enough and carbon builds up on the plugs? I assumed that raw water cooling is a problem for these engines when running slow or at normal cruise. I pulled the plugs this weekend on the 2013 I just bought. The boat has 97 hours on the engines, but the plugs have some build up and the appearance looks like the were beginning to rust (I assume they were never replaced, but all look exactly the same). I have new ones going in, but I'm not sure what to be looking for.
 
Messages
3,270
Ratings
2,994 93
Points
268
Location
Florida
Boat Make
Yamaha
Year
2014
Boat Model
Other
Boat Length
Other
#8
Well I use my stuff constantly last year I spent 151 days on the water that is how I get so many hours . A set of plugs a year may not be necessary but it's just habit. I have several things I do before any new engine ever sees the water. I know I have done many posts listing those . If I can't get any more 1800 engines I probably will keep the ones I have longer than the usual 650 hours. I always put a 5 year warranty on my new skies and I log in that amount of hours in 4 years. That is because I have 2 and I alternate them each time I go out I use a different one . And I drive them very slowly and cautiously.
 
Last edited:

swatski

Jetboaters Fleet Admiral
Messages
8,789
Ratings
9,441 138
Points
493
Location
Saint Louis, MO
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#9
I've meant to ask why we are changing the plugs so often? Is it because the engines don't get hot enough and carbon builds up on the plugs? I assumed that raw water cooling is a problem for these engines when running slow or at normal cruise. I pulled the plugs this weekend on the 2013 I just bought. The boat has 97 hours on the engines, but the plugs have some build up and the appearance looks like the were beginning to rust (I assume they were never replaced, but all look exactly the same). I have new ones going in, but I'm not sure what to be looking for.
I must say the spark plug replacement is a bit of a habit, not necessarily needed every year - in 1.8s. Mine look something like that, all the exact same:
upload_2018-4-10_23-54-38.png

Do those need to be changed? - probably not.

In MR-1s I think it is a different story - plug changes seem to cure a vast array of problems there, for reasons that are not completely clear...

--
 

boudin

Well-Known Member
Messages
312
Ratings
230 8
Points
58
Location
Lake Livingston, Texas
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
21
#10
In MR-1s I think it is a different story - plug changes seem to cure a vast array of problems there, for reasons that are not completely clear...
Much of the problem I've seen comes from folks consistently overfilling the oil reservoir, and subsequently fouling plugs. When overfilled, oil will blow back in to the intake through the breather hose. Make sure the check the oil when the engine is well warmed up, and oil is pumped up back into the reservoir.

-Greg
 

AZ Native

Jet Boat Lover
Messages
191
Ratings
205 7
Points
83
Location
Phoenix, Arizona 85044
Boat Make
Yamaha
Year
2013
Boat Model
Limited S
Boat Length
24
#12
@swatski Thanks for the photo. Mine don't look that good, reinforcing my contention that the plugs haven't been replaced since the boat was built. The new ones arrived this week from Summit Racing. I'll get to see if they improve performance. Having just moved from the MR-1's in my 2005 to the 1.8's in my 2013, I can vouch for the issues with plugs fouling and overfilled oil getting sucked into the intake and air filters. The 1.8's don't have either of these related issues.
 
Last edited:
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