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Loss of Power maybe Fuel Pump?

dusman2000

Active Member
Messages
4
Reaction score
4
Points
42
Boat Make
Yamaha
Year
2013
Boat Model
SX
Boat Length
19
Okay i'm new to this forum I've had my 2013 SX190 for 2 years. Let me start off with this. Last year 2 times while out the boat wouldn't start. As if the fuel pump was not working. It finally did start and it didn't happen again all summer after those two instance.

This year we take the boat out, And at first seemed okay but almost felt like it had bad gas. The boat had half a tank in it when i put it away in november I only run 91-93 oct. and 99.9% sure i had non ethonal in the tank before i put it away for winter. I added 15-20 gals that dat before we went to the lake of 93 oct with Ethonal because I couldn't find Non that was 91 or 93 for some reason at the same place i had used last summer.

Boat started easily as it always has. We take off and boat seems to be running okay we ran for about 10 mins we shut down for a few mins to figure out where we are going to navigate to and are we swimming or pulling a tube first etc.

I start the boat back up and take of and still seems like it somewhat okay but maybe a little less power than usual. Then from then on it got worse and worse of lossing power. The idle started feeling odd but then it would clear up.

We would take off and some times get on plane and other times it would just stay at 6000-6200 rpm and go 12-14 mph. it would then hook up and go 30+ while it would be stuck at 12-14mph it would just randomly snap out of it THEN it would decelearate back down again. One time it was stuck at 12-14 and then 5 mins of that speed it just took of and ran like it should for about 2-3 mins and then boom right back to the slow unhappy boat. The boat had the same crew in it of kids and adults we had last year at this same lake when we had no issues flying down the lake previous year.

So i'm trying to figure out if i have bad fuel pump. Bad gas. I did determine that my Wear ring looks to be .500mm+ on one side and just under .500mm on the other side. Shaft seems tight prop looks perfect. Boat has about 150 hours on it. So i'm sure i may have some cavitation but for it just go and slow down and go and slow down seems weird to me and if it was caviation shouldn't i be able to still turn 7200+ rpm like I always have even if it was the Wear ring?

No warning lights have come up etc. The way it acted felt way to consistent for bad gas to be the issue but who knows. Any help would really be appreciated.
 

Dmitry

Member
Messages
4
Reaction score
1
Points
10
Boat Make
Yamaha
Year
2016
Boat Model
212
Boat Length
22
I have similar experience with my Yamha 212x 2016. I'm trying to figure out what can be from. I didn't add any ethonal in the tank before i put it away for winter.
 

dusman2000

Active Member
Messages
4
Reaction score
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Points
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Boat Make
Yamaha
Year
2013
Boat Model
SX
Boat Length
19
After Posting I found another person that was having a very very similar issue. And this really feels like what mine could be. HIs was a Fuel Injector which makes a lot of sense. Its a long Thread but read to the very bottom. I appreciate any Thoughts on this. Link posted below

Thanks

 

granitetech

Jet Boat Lover
Messages
28
Reaction score
45
Points
72
Location
Lake Hartwell
Boat Make
Yamaha
Year
2011
Boat Model
AR
Boat Length
24
It might be the spark plugs. Mine was sputtering occasionally and then it wouldn't get above 6000 rpm. Changed the plugs and it is running great now
 

dusman2000

Active Member
Messages
4
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Boat Make
Yamaha
Year
2013
Boat Model
SX
Boat Length
19
I've got 4 NGK LFR6A on my table right now about to put in and see. I have not replaced them since I got the boat but the previous owner had often before i got it. Are these motors known for needing new plugs each year??
 

Dmitry

Member
Messages
4
Reaction score
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Points
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Boat Make
Yamaha
Year
2016
Boat Model
212
Boat Length
22
I've got 4 NGK LFR6A on my table right now about to put in and see. I have not replaced them since I got the boat but the previous owner had often before i got it. Are these motors known for needing new plugs each year??
Yamaha recommends you change your spark plugs annualy or after every 100 hours of operation.
 

dusman2000

Active Member
Messages
4
Reaction score
4
Points
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Boat Make
Yamaha
Year
2013
Boat Model
SX
Boat Length
19
You've described bad spark plug symptoms here. Change them and your issue will go away.
You where right. Replaced the Spark Plugs (LFR6A) ran the boat tonight. Was able to turn 7600rpm and get up to 42.5mph with a little chop on the water and a 8-10mph wind! I ran about 1/3 of a tank of gas stopping and starting and idle to take off multiple times and it ran perfect.

Thank you everyone for your Reponses!
 

HangOutdoors

Jetboaters Admiral
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Location
Royal Oak, MI
Boat Make
Yamaha
Year
2020
Boat Model
AR
Boat Length
21
I change my oil and spark plugs every year and call it good.
 

Thermobrett

Jetboaters Admiral
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Location
Lithia, Florida
Boat Make
Boatless
Year
2022
Boat Model
SX195
Boat Length
19
I follow Yamahas recommended service plan in the owner manual. As I only have 52hrs on my boat I still do the oil change and plugs at the beginning of the season as a piece of mind. These engines are high RPM and I’m sure burn hot so a little money upfront can prevent simple problems down “stream”. Since I have a supercharger on mine, I always run premium fuel as recommended. I like to believe Yamaha did their research during the R&D process and that’s why they tell us to use certain products on our engines.
 
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