Motor shaking / loss of power.. any ideas?

[HEMAN]

so the previous trip. my engine started acting up... and this past trip over the weekend.. she just didn't want to cooperate... takes a bit to start up.. but i think that could just be the cold weather..

so the motor shakes pretty bad now once it's running.. and then at full throttle.. it's not even at full power.. i would say it's running 30% :Evil:.. the rentals at Skinner were passing me up... it took forever to move around...

anyone have any ideas? it's a Yamaha 15 hp 4stroke.

Going to check replace the spark plugs next.. i'm thinking maybe one of the cylinders is not firing?

I am going to bring it in for a normal service none the less.. but not sure if they will diagnose anything for me without charge... just thought i'd ask here to see if anyone has any good info.. thanks guys..

[MAVERICK27]

Just take the plugs out one by one, still connected to the spark plug wire (high tension leads) and crank it with the plug touching a ground, like the cylinder. You should see spark. You will probably find that one or more cylinders are not firing....then find where the problem is from there...could just be a bad plug...I know car engines pretty well...and that is the same diagnosis tool...

[OnDaHunt4Fish]

make sure that you check to make sure that the all plug wire are snug that could cause it *** well as the foam on the inside of the hood ...hope that helps

[GeordyBass]

hmmmmm,i think you should try checking the bulb to you gas tank?Happened to me once.Then try checking the plugs like they said here...It might be something with the fuel,magneto,pistons,or carb/injectors???(yes 4strokes have carbs,but they are different than 2 strokes)

[TRDEXPERT]

Start with the basic, replace spark plugs and wires, then try the compression test like the other fnn member commented

[yamafish]

Arghhhhhhhh...... That's my old Duroboat / Yamaha

Heman,

Take it here Johnson Marine in Ontario .. http://www.johnson-marine.com/JohnsonMarine/Welcome.html
Ask for Brian. He is the very best Yamaha mechanic around.

While you are there...
Go pick up some Yamaha 4 stroke ringfree from them.

If you troll all day long.. make sure before you head on back to run a couple of "hot laps"

You want a deal on a near new Crestliner I/O drive 18.5 ft?

YamaFish

[GeordyBass]

Arghhhhhhhh...... That's my old Duroboat / Yamaha

Heman,

Take it here Johnson Marine in Ontario .. http://www.johnson-marine.com/JohnsonMarine/Welcome.html
Ask for Brian. He is the very best Yamaha mechanic around.

While you are there...
Go pick up some Yamaha 4 stroke ringfree from them.

If you troll all day long.. make sure before you head on back to run a couple of "hot laps"

You want a deal on a near new Crestliner I/O drive 18.5 ft?

YamaFish
your a new boat,boat whore...
i'm an old boat,boat whore...
:LOL: :LOL: :LOL: :LOL: :LOL:

[TRDEXPERT]

Geobassmaster818
hows that boat you bought for 500.00 dollars?

[GeordyBass]

Geobassmaster818
hows that boat you bought for 500.00 dollars?
who's geobassmaster818?
i dont know of him????haha

I luv that thing!!does me well and never stalled on me...it is lucky as hell too!

[Rooster]

Arghhhhhhhh...... That's my old Duroboat / Yamaha

Heman,

If you troll all day long.. make sure before you head on back to run a couple of "hot laps"

You want a deal on a near new Crestliner I/O drive 18.5 ft?

YamaFish

Hey that was my boat also :LOL: I sure miss that boat. Roger he doesn't troll,, He is a bass master.

Heman im sure its something minor, probably just needs a good carb cleaning. BTW post some pics,,i would love to see what ya did to it.

[Rooster]

Ohh i just remembered, Is your gas tank full? Are you opening the valve? You can't have the gas tank completely full. Empty some gas out and i bet it will run like a champ.

[troutdog]

Hey that was my boat also :LOL:

Rob that made me laugh out loud when I read that for some reason! You are all over the place :ROFL:

Hope your boat is back up to speed with minimal efort and funds, good luck Heman.


TD

[yamafish]

Bassmaster818 - You and I truly have a problem with buying too many boats... Is there some kind of outreach we can go to like AA? :LOL:
Dude, I'm a mess.. I got two boats again... I need help - for reals
How many boats are you up to bro at this time?


ok.. pics of that boat in the beginning......
http://i62.photobucket.com/albums/h92/rfish7/P6300025.jpg
http://i62.photobucket.com/albums/h92/rfish7/P6300028.jpg
http://i62.photobucket.com/albums/h92/rfish7/P3060285.jpg
http://i62.photobucket.com/albums/h92/rfish7/P1080060.jpg That boat is a fish killer...

I then sold it to RTR
Heman - history on your ride...I purchased it from the orig owner. He is a fishing guide in Alaska. He bought this ride to leave down here at a relatives home in So Cal. He then decided that he wanted to sell it..

Post some pics of the boat RTR and Heman
curious to see how the boat has changed...


peace
YamaFish

[HEMAN]

Arghhhhhhhh...... That's my old Duroboat / Yamaha

Heman,

Take it here Johnson Marine in Ontario .. http://www.johnson-marine.com/JohnsonMarine/Welcome.html
Ask for Brian. He is the very best Yamaha mechanic around.

While you are there...
Go pick up some Yamaha 4 stroke ringfree from them.

If you troll all day long.. make sure before you head on back to run a couple of "hot laps"

You want a deal on a near new Crestliner I/O drive 18.5 ft?

YamaFish

Yes, they were closed yesterday.. i was going to call them today or tomorrow.. I will ask for Brian. thanks.


Hey that was my boat also :LOL: I sure miss that boat. Roger he doesn't troll,, He is a bass master.

Heman im sure its something minor, probably just needs a good carb cleaning. BTW post some pics,,i would love to see what ya did to it.

Yup.. i don't troll.. YET. =) gotta learn everything... i figure its something small.. been fishing on it every week or so... so i couldnt bring it in for the annual service like i wanted.


Ohh i just remembered, Is your gas tank full? Are you opening the valve? You can't have the gas tank completely full. Empty some gas out and i bet it will run like a champ.

ok. i will check that.. the gas tank is pretty full... and yes the valve is open. i'll check it out with less fuel in there... as well.. do you know why it would do that?


Bassmaster818 - You and I truly have a problem with buying too many boats... Is there some kind of outreach we can go to like AA? :LOL:
Dude, I'm a mess.. I got two boats again... I need help - for reals
How many boats are you up to bro at this time?


ok.. pics of that boat in the beginning......
http://i62.photobucket.com/albums/h92/rfish7/P6300025.jpg
http://i62.photobucket.com/albums/h92/rfish7/P6300028.jpg
http://i62.photobucket.com/albums/h92/rfish7/P3060285.jpg
http://i62.photobucket.com/albums/h92/rfish7/P1080060.jpg That boat is a fish killer...

I then sold it to RTR
Heman - history on your ride...I purchased it from the orig owner. He is a fishing guide in Alaska. He bought this ride to leave down here at a relatives home in So Cal. He then decided that he wanted to sell it..

Post some pics of the boat RTR and Heman
curious to see how the boat has changed...


peace
YamaFish

RTR and Yamafish... i have not had a chance to do anything to it yet.. just moved some rod holders around.. cut the trailer tongue down... i have plans for it.. just no time... every weekend i wanted to do something. .i just end up going fishing instead.. haha..

i will definitely keep you updated... Thanks for the history and information guys.. i will keep you updated...

[kelly k]

so the previous trip. my engine started acting up... and this past trip over the weekend.. she just didn't want to cooperate... takes a bit to start up.. but i think that could just be the cold weather..

so the motor shakes pretty bad now once it's running.. and then at full throttle.. it's not even at full power.. i would say it's running 30% :Evil:.. the rentals at Skinner were passing me up... it took forever to move around...

anyone have any ideas? it's a Yamaha 15 hp 4stroke.

Going to check replace the spark plugs next.. i'm thinking maybe one of the cylinders is not firing?

I am going to bring it in for a normal service none the less.. but not sure if they will diagnose anything for me without charge... just thought i'd ask here to see if anyone has any good info.. thanks guys..

Hey Heman, I had that same thing happen to my motor(Yamaha 15hp four stroke) took it in and all they said is the carb needs rebuilding (what???? Its only 8months old) so I take the carb apart, what do you know? NOTHING WRONG!!!!!!!!!!!

My question is: what gas are you using? is it Premium? I have a hunch that regular is the gas to run in these motors, I went back to regular and have not had that issue since, still scratching my head on that one............. Kelly k

[HEMAN]

Hey Heman, I had that same thing happen to my motor(Yamaha 15hp four stroke) took it in and all they said is the carb needs rebuilding (what???? Its only 8months old) so I take the carb apart, what do you know? NOTHING WRONG!!!!!!!!!!!

My question is: what gas are you using? is it Premium? I have a hunch that regular is the gas to run in these motors, I went back to regular and have not had that issue since, still scratching my head on that one............. Kelly k

i am running premium... come to think of it.. the problem did start when i finally filled up the tank with 91 octane... i will dump the gas and try regular next... i will add it to my list of things to check... thank you very much for the info Kelly.

[GeordyBass]

i am running premium... come to think of it.. the problem did start when i finally filled up the tank with 91 octane... i will dump the gas and try regular next... i will add it to my list of things to check... thank you very much for the info Kelly.

yeah heman...91 octane is too flammable for outboards....89 is the highest you can put....regular gas is also a little thinner too....it burns slower so the motor doesn't do too much work(or at least that's what I think....lol)i've also noticed the difference on my 9.9 merc 4 stroke and regular gas makes it run way better....

[GeordyBass]

Bassmaster818 - You and I truly have a problem with buying too many boats... Is there some kind of outreach we can go to like AA? :LOL:
Dude, I'm a mess.. I got two boats again... I need help - for reals
How many boats are you up to bro at this time?


ok.. pics of that boat in the beginning......
http://i62.photobucket.com/albums/h92/rfish7/P6300025.jpg
http://i62.photobucket.com/albums/h92/rfish7/P6300028.jpg
http://i62.photobucket.com/albums/h92/rfish7/P3060285.jpg
http://i62.photobucket.com/albums/h92/rfish7/P1080060.jpg That boat is a fish killer...

I then sold it to RTR
Heman - history on your ride...I purchased it from the orig owner. He is a fishing guide in Alaska. He bought this ride to leave down here at a relatives home in So Cal. He then decided that he wanted to sell it..

Post some pics of the boat RTR and Heman
curious to see how the boat has changed...


peace
YamaFish

oh really???lol....i only have 2 boats and a jet ski.One of my boats is my main 17' lowe bass boat fully loaded....the other one is a 9' achilles inflatable which I like to use in the harbors because I don't really have to completely clean it like the other one.I also have a 3.5hp Nissan,5hp Nissan,9.9hp Mercury 4stroke,and a couple trolly motors.Also My yamaha jet ski...which I got 4 free running well...i'm more of the deal finder and sell my boats at a low price as well....win,win...lol...

[lizzay]

Hey Heman, I had that same thing happen to my motor(Yamaha 15hp four stroke) took it in and all they said is the carb needs rebuilding (what???? Its only 8months old) so I take the carb apart, what do you know? NOTHING WRONG!!!!!!!!!!!

My question is: what gas are you using? is it Premium? I have a hunch that regular is the gas to run in these motors, I went back to regular and have not had that issue since, still scratching my head on that one............. Kelly k

Utilize the Warranty that came with it. I'm getting nervous about my motor after hearing this...

[lizzay]

Not "thread jacking" but could this mean that I might not be getting the most out of my motor too??? Since I bought it I've only used 91

[diamondbear]

for what its worth , my 40 hp merc. o/b was purchased 4 years ago and my mechanic told me to run only lower octane reagular gas , i never did ask why , now i know .

[lizzay]

for what its worth , my 40 hp merc. o/b was purchased 4 years ago and my mechanic told me to run only lower octane reagular gas , i never did ask why , now i know .

okay, down to 89 only then but if there's anybody out there that know's the mechanics as to why and would it really make you lose power please explain. Thanks.

[migfrias]

I was having similar problems with my 15hp Evanrude. I took it in for service and they ended up replacing "the power head". It is a electrical component that operates "one" of the cylinders in my 2 stroke. Part was $118.00, labor was about $150.00 (three screws and a din connection) :(

miguel

[kelly k]

okay, down to 89 only then but if there's anybody out there that know's the mechanics as to why and would it really make you lose power please explain. Thanks.

Lizzay, this is only my opinion, and I don't want to get into a big dissertation on the internal combustion engine.So here we go, the fuel we are burning in the outboards is supposed to "match" the performance of how the engine is setup, therefore with premium grade gasoline with the higher octane rating, burns slower or harder to ignite and with the lower compression and retarded ignition timing we have in our motors, it struggles to get a complete burn,on the other hand when the components "match" the fuel requirements, such as higher compression,advanced ignition timing and a high revving engine, the efficiency of the combustion process(burn) is complete, there is also a down side to too much compression and thats detonation, but thats another story.

So regular gas is easier to burn(burns faster) in our outboards, keeps the heat in the chamber for a complete combustion process.

hope this sheds some light on the subject.. Kelly k

One thing I haven't looked at is hotter spark plugs since its hard to keep the heat in the chamber because of the cold water cooling...... hmmmmm.........

[kelly k]

Utilize the Warranty that came with it. I'm getting nervous about my motor after hearing this...

Sorry I didn't answer this first, I will try to remember why they would not put this under warranty, I think since this was an exploratory check up it was not covered under warranty, I think they charged me $80 to tell me the carb needs rebuilding........ Kelly k

[HEMAN]

k so i siphoned all the gas out of the tank tonight.. and will fill will 87 tomorrow.. just half the tank and see how it goes.. will be at the Pudd if anyone is going to be out there...

i will update if it runs any better.

[kelly k]

k so i siphoned all the gas out of the tank tonight.. and will fill will 87 tomorrow.. just half the tank and see how it goes.. will be at the Pudd if anyone is going to be out there...

i will update if it runs any better.


If I may suggest, You might want to run the engine with the water hooked up so that any premium gas thats left in the system is burned off, I run my motor on the stand before I go out, just to make sure everythings ok, it also makes it easier to start in the morning.

Kelly k

[GeordyBass]

k so i siphoned all the gas out of the tank tonight.. and will fill will 87 tomorrow.. just half the tank and see how it goes.. will be at the Pudd if anyone is going to be out there...

i will update if it runs any better.
you know you could put that old gas in your car dont you?

Good luck!:Smile:

[HEMAN]

ok.. so i siphoned the old gas out to another tank (temporary), filled up with some 87 octane.... still having same problem..

full throttle.. .power is still very weak...

although the shaking has seemed to have gone down from before...

i will be checking spark plugs and maybe even take a look at the carb later tonight..

i talked to Brian at Johnson Marine in Ontario.. and will be bringing it to them next week for an annual tune up and have them check the problem...

[lizzay]

Lizzay, this is only my opinion, and I don't want to get into a big dissertation on the internal combustion engine.So here we go, the fuel we are burning in the outboards is supposed to "match" the performance of how the engine is setup, therefore with premium grade gasoline with the higher octane rating, burns slower or harder to ignite and with the lower compression and retarded ignition timing we have in our motors, it struggles to get a complete burn,on the other hand when the components "match" the fuel requirements, such as higher compression,advanced ignition timing and a high revving engine, the efficiency of the combustion process(burn) is complete, there is also a down side to too much compression and thats detonation, but thats another story.

So regular gas is easier to burn(burns faster) in our outboards, keeps the heat in the chamber for a complete combustion process.

hope this sheds some light on the subject.. Kelly k

One thing I haven't looked at is hotter spark plugs since its hard to keep the heat in the chamber because of the cold water cooling...... hmmmmm.........

Hence the reason why higher reving/faster cars states us to use high octane fuel because it needs that much to match up with the performance of the engines. Very well done. Thanks for all that info.

[Granny Fish]

Sounds exactly like what was happening to us not too long ago. We found we had water in the gas. There is an additive you can buy at the autoparts store for a coulple bucks that dries it out, but if you've changed your gas, it could be water in the engine. May need to check that the plugs aren't wet and check filters as well. Cost us a lot to find out it was an easy fix and preventative.

[HEMAN]

Sounds exactly like what was happening to us not too long ago. We found we had water in the gas. There is an additive you can buy at the autoparts store for a coulple bucks that dries it out, but if you've changed your gas, it could be water in the engine. May need to check that the plugs aren't wet and check filters as well. Cost us a lot to find out it was an easy fix and preventative.

thanks granny.. i'll be doing some other checks tomorrow (err later today based on timestamp) and see how it goes...

[HEMAN]

ok.. so finally got around to replacing the plugs... took the boat out to the Pudd today for a quick test run.. and the boat and engine are running like a champ now!...

[kelly k]

ok.. so finally got around to replacing the plugs... took the boat out to the Pudd today for a quick test run.. and the boat and engine are running like a champ now!...

Had me scratching my head on that one, its kind of hard to diagnose problems without looking at the real thing. Glad you found the problem. Kelly k

[Rooster]

Nicely done Heman, Now if you can just learn to catch a bass on it now. :Envious::Envious::Envious: Let me know when its good and we will head out. Looking foward to learning from ya bro..

[labboss2003]

hey had the same problem went tru all the same things you did ran good for a couple of trips then the same thing again.........ended up being the timming ring on the flywheel was broke free sometimes it would catch sometimes it would spin.....so just sayin if it starts doin it again pull your fly wheel and check.............

[HEMAN]

hey had the same problem went tru all the same things you did ran good for a couple of trips then the same thing again.........ended up being the timming ring on the flywheel was broke free sometimes it would catch sometimes it would spin.....so just sayin if it starts doin it again pull your fly wheel and check.............

cool thanks.. i will keep that in mind.. took it out to Skinner yesterday and it was still running great...