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2015 AR240 Port Engine crank but no start...Please help

Nkc240

Active Member
Messages
13
Ratings
6 4
Points
43
Boat Make
Yamaha
Year
2015
Boat Model
AR
Boat Length
24
#1
Hi guys,

Rough two days. I took my 15 AR240 (130hrs each side) to a lake and the port engine suddenly shut off like a lanyard was pulled. It was an hour long ride to the lake travelling at 5800-6000rpm on both engines. No signs of overheating, no warnings or check engine, no studder, just shut down. I turned everything off including the power switches and SB engine was fine but port engine would crank but not start. After exhausting all my possible options under the circumstances, I had to travel about 4 hours on one engine running about 6000rpm home.

These are the things I've checked over the last two days.
-checked the clean out ports, latch buttons and all were fine.
-did everything I could with the lanyard
-swapped connectors for the kill switch
-adjusted cleanout hatch switches - my understand is that the switch would not even crank if not depressed
-Fuel is good and had roughly 60% tank
-swapped fuel lines and all plugs at the fuel pump
-there's spark in all 4 plugs
-Battery is good
-checked all connections (unplugged and plugged back)
-Engine level and oil is good

Now i'm trying to source a YDS to see if it shows any codes. The onboard diagnostics on the screen doesn't show anything. No codes popped up, both engines 01 No Malfunction. I check regularly because I sometimes have a code 76 on the port engine that corresponded with the cruise control not working. I've call a Yamaha tech and he's walked me thru everything he can think of but unfortunately, their shop is 5 hours away and nothing worked as well.

Any suggestions would be appreciated. I just want to try everything I can before I pull it in to a shop. Thanks guys.
 

swatski

Jetboaters Fleet Admiral
Messages
8,576
Ratings
9,222 137
Points
493
Location
Saint Louis, MO
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#2
Hi guys,

Rough two days. I took my 15 AR240 (130hrs each side) to a lake and the port engine suddenly shut off like a lanyard was pulled. It was an hour long ride to the lake travelling at 5800-6000rpm on both engines. No signs of overheating, no warnings or check engine, no studder, just shut down. I turned everything off including the power switches and SB engine was fine but port engine would crank but not start. After exhausting all my possible options under the circumstances, I had to travel about 4 hours on one engine running about 6000rpm home.

These are the things I've checked over the last two days.
-checked the clean out ports, latch buttons and all were fine.
-did everything I could with the lanyard
-swapped connectors for the kill switch
-adjusted cleanout hatch switches - my understand is that the switch would not even crank if not depressed
-Fuel is good and had roughly 60% tank
-swapped fuel lines and all plugs at the fuel pump
-there's spark in all 4 plugs
-Battery is good
-checked all connections (unplugged and plugged back)
-Engine level and oil is good

Now i'm trying to source a YDS to see if it shows any codes. The onboard diagnostics on the screen doesn't show anything. No codes popped up, both engines 01 No Malfunction. I check regularly because I sometimes have a code 76 on the port engine that corresponded with the cruise control not working. I've call a Yamaha tech and he's walked me thru everything he can think of but unfortunately, their shop is 5 hours away and nothing worked as well.

Any suggestions would be appreciated. I just want to try everything I can before I pull it in to a shop. Thanks guys.
Sounds like it could be the dreaded timing chain failure, possibly. Pulling the head cover would answer that definitively, I think - unless anyone would object here.

Would need a new gasket to replace the old one, non-reusable., but it is not very expensive and only 8-10 bolts.

The not so bad news(a silver-lining) would be - Yamaha typically covers engine replacement for TC failure even out of warranty. But it is a bummer.

I hope I'm wrong and it is something simpler...
 

Beachbummer

Jet Boat Junkie
Messages
1,251
Ratings
764 10
Points
148
Location
Houston TX
Boat Make
Yamaha
Year
2008
Boat Model
SX
Boat Length
23
#3
I think broken Timing belt=No Compression on some cylinders. If you fear this, do a compression check to confirm all is well internally.

You have tried quite a bit. I'm sorry I can't offer more than what you have tried, except checking for spark. Not sure how to do it other than watching the spark plugs while they are out which is bad for the ignition system...someone probably will offer a better idea.

EDIT: Never mind, you already checked spark!!
 
Last edited:

Neutron

Jetboaters Lieutenant
Messages
1,279
Ratings
1,269 14
Points
163
Location
New Bern, NC
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#4
Spray something like carb cleaner or brake cleaner into throttlebody and see it it fires
 

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
#5
Air, fuel, spark (and compression). It sounds like you've checked all this except compression. You don't necessarily need a gauge--just pull the plugs and put your finger over the hole while cranking. As others have said, possible broken timing chain.

-Greg
 

Jimminh

Well-Known Member
Messages
6
Ratings
8
Points
63
Location
Renton, Washington
Boat Make
Yamaha
Year
2010
Boat Model
Limited S
Boat Length
24
#6
before you start taking the motor apart you can check if the timing chain is broken just by pulling the oil fill cap, there's a small hole just under it where you can see the intake cam and see if it rotates when someone else turns the key.
 

Nkc240

Active Member
Messages
13
Ratings
6 4
Points
43
Boat Make
Yamaha
Year
2015
Boat Model
AR
Boat Length
24
#7
Thanks for all the info. I just tried swapping the cam sensors and no luck as well. I'm getting a more mechanically inclined friend over and we'll determine if it's a timing chain issue. Wish me luck boys.
 

Nkc240

Active Member
Messages
13
Ratings
6 4
Points
43
Boat Make
Yamaha
Year
2015
Boat Model
AR
Boat Length
24
#8
Swapped the clean out hatch wiring, no luck.

Cams rotates and doesn't sound like an engine issue at all.

Trying to swap the entire relay box now.
 

spatty99

Jet Boat Addict
Messages
270
Ratings
154 3
Points
103
Location
Orlando, FL
Boat Make
Moomba
Year
2017
Boat Model
Other
Boat Length
21
#10
That really sucks, but on the bright side this should be fully covered by Yamaha! There is a lot of timing chain failure history on the forum to back you up if you encounter any push back.
 

Nkc240

Active Member
Messages
13
Ratings
6 4
Points
43
Boat Make
Yamaha
Year
2015
Boat Model
AR
Boat Length
24
#11
Thanks for all the help guys and you were right from the get go. I really hope Yamaha covers this now.
 

Neutron

Jetboaters Lieutenant
Messages
1,279
Ratings
1,269 14
Points
163
Location
New Bern, NC
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#12
Keep us posted on the cause
 

Nkc240

Active Member
Messages
13
Ratings
6 4
Points
43
Boat Make
Yamaha
Year
2015
Boat Model
AR
Boat Length
24
#13

swatski

Jetboaters Fleet Admiral
Messages
8,576
Ratings
9,222 137
Points
493
Location
Saint Louis, MO
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
#14
I don't think I'd be able to provide info on the cause. Timing chain failure seems to be a known issue after doing some searching. Hopefully this will be warrantied as it seems absurd that a timing chain fails at 130hrs. They did a revision on the timing chain for 2016 it seems to combat this problem.

https://jetboaters.net/threads/have...warranty-and-how-has-yamaha-handled-it.10799/
Yes, they changed the TC in 2016 MY, apparently all engines after 9/15 production date or somewhere there.
The new ones have 4 links.
Could you post a picture of your broken TC, if you have one?

Fingers crossed this will be covered by Yamaha!!!

before you start taking the motor apart you can check if the timing chain is broken just by pulling the oil fill cap, there's a small hole just under it where you can see the intake cam and see if it rotates when someone else turns the key.
Now... I'm curious about this comment...? @Jimminh do you want to tell us if those symptoms make sense?

--
 

Jimminh

Well-Known Member
Messages
6
Ratings
8
Points
63
Location
Renton, Washington
Boat Make
Yamaha
Year
2010
Boat Model
Limited S
Boat Length
24
#15
I got the tip on the oil cap/hole check from greenhulk where there are a dozen threads about the 1.8 broken chains. I checked it on my boat and you can definitely seen the cam rotating through that little hole. Maybe if it doesn't move and you're never seen it moving through the little hole you can't tell? I've not had personal experience with a broken chain...and I'm not going to temp fate by saying 'yet'.
 
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