Yamaha F150 troubles

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Zumytunes

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Gulfstream
Hello, I am looking for some advise to see if anyone can see a smoking gun.. these are on my 2000 Gulfstream-

2011 port engine, troubles just started, 628 hours. Basically sounds like the motor is in limp mode, vibrating, etc.

2007 Stbd engine- runs great, 1436 hours

The port engine seems like maybe a fuel related problem, exhaust looks ok no corrosion out the side of the guide etc.

When under load it vibrates, although no alarm codes on the Yamaha gauge, temps, oil pressures all good.

I will run through the basics- check the fuel filter, fuel/water separator, but thinking maybe injector or fouled plugs?

My buddy was saying to check the throttle position sensor & oxygen sensors. Or maybe fuel pump? Harmonic balancer?

Stbd engine runs perfect which is strange running off the same fuel tanks, etc. Fuel is actually good in my tanks too.

Outboard mechanics are few and far between in my neck of the woods so thought I would start here..any input is appreciated!


Here are a couple videos

https://www.dropbox.com/scl/fo/481v...ey=oxgvwyld70kft7qegs6rzjb65&st=q3qcc12m&dl=0
 

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Nothing strange about the stbd engine running well off "tank 1" and port does not when using "tank 1". That just means that the vent system (one of the variables at play) is fine.

It's not clear... does the vibe happen at all RPM's under load?

Put a fuel pressure gauge on there and monitor. Report back with that info.

There's a bunch of things that can cause this... for example...

-- fuel pickup
-- fuel lines
-- fuel diverter
-- fuel filter
-- LP pumps
-- HP pump
-- HP filter
-- injectors
-- and I'm probably forgetting a few!

Systematic diagnosis is key. Which brings us back to one of the best places to start... pressure
 
Thanks for the feedback Denis, yes she's vibrating at idle then as you rev up get worse and worse and sounds like starving for fuel or air or something, going to dig in more after work & I will report back.

All drive train looks good, prop, shaft, thrust washer, etc.
 
Start the motor, run at around 1200 revs in neutral and pull off and reconnect one spark plug wire at a time. Listen and see if the motor changes how it is running. If all cylinders are good, the motor should run rougher or slower when a plug wire is remove.
If one or more cylinders when unplugged do not change your next step is to isolate a spark or an injector issues ( Yes there are other really serious problems, especially if 2 cylinders next to each other are bad but let's be hopeful)
We can go from there when we know if a cylinder is acting up. If it is, remove the spark plug and take a look at its condition. If it looks OK, swap that cylinder's spark plug with one from a good cylinder and see what happens. If you are lucky, the problem, will move and you need new plugs. If the problem remains, the next step is to swap the spark coil and do a similar test and comparison
 
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I've been zapped more than once from a plug wire. Slow learner I guess. What's the preferred method to pull wires on a running engine and not get zapped?
 
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family affair said:
I've been zapped more than once from a plug wire. Slow learner I guess. What's the preferred method to pull wires on a running engine and not get zapped?
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Don't use your hands :) You should be protected enough by the boot but as things get older there are instances of leakage.

Using a pair of pliers with a rubber grip should be enough. You can get plug boot pliers if you want to get fancy.

Don't put your other hand on any metal part of the engine.

Wear a glove if you want extra protection.
 
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I've used pliers before, but thought it was a little rough on the insulation. I didn't know if a glove would be thick enough to prevent leakage or arcing thru the pores of the material.
 
family affair said:
I've used pliers before, but thought it was a little rough on the insulation. I didn't know if a glove would be thick enough to prevent leakage or arcing thru the pores of the material.
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Gloves can only help. I don't use gloves - just pliers - and, yes, I'm careful with the boot. Most of the time, though, I use plug pliers.
 
I had a problem where I had vibration in idle and low RPMs. It ended up being one fouled plug in both engines; they were running on 3 cylinders. I replaced the plugs before fogging the engines to put away for winter. I didn't think the plugs could be bad; they looked good when I pulled them. Ended up putting new ones in again, and they ran great. I would try new plugs. I went through cleaning injectors, fuel pressure, checking the VST filter, and running the computer on it to sink the engines to find out it was the plugs
 
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Hockeysurf7 said:
I had a problem where I had vibration in idle and low RPMs. It ended up being one fouled plug in both engines; they were running on 3 cylinders. I replaced the plugs before fogging the engines to put away for winter. I didn't think the plugs could be bad; they looked good when I pulled them. Ended up putting new ones in again, and they ran great. I would try new plugs. I went through cleaning injectors, fuel pressure, checking the VST filter, and running the computer on it to sink the engines to find out it was the plugs
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What was your motor model? What method did you use to fog the motor?
Was it the same cylinder in both motors that was mis firing?
 
seasick said:
What was your motor model? What method did you use to fog the motor?
Was it the same cylinder in both motors that was mis firing?
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Repowered with 2006 yamaha f150 didn't get the boat in that summer so i winterized it like it was a two stroke with fogging spray and did the plugs before. I got it in the water this summer. I didn't know how the engines were going to run. So I ran it thinking that they probably vibrated a bit and didn't realize how much power I lost until after I put in new plugs. I am not sure what cylinder, but I think it was the bottom ones
 
Hockeysurf7 said:
Repowered with 2006 yamaha f150 didn't get the boat in that summer so i winterized it like it was a two stroke with fogging spray and did the plugs before. I got it in the water this summer. I didn't know how the engines were going to run. So I ran it thinking that they probably vibrated a bit and didn't realize how much power I lost until after I put in new plugs. I am not sure what cylinder, but I think it was the bottom ones
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I am not sure exactly what Yamaha says about fogging but on some motors, it is not recommended to fog through the intake since the oil can damage the mass air flow sensor.
If the plug that went bad was the same on both engines, I have to wonder if it was something you did that fouled the plugs.
I will try to see if I can find the fogging recommendations for your motor. If anyone knows, chime in!
 
Hockey,
That happened to me a couple of years ago. I have yammy 250 HPDI vibration and shaking and little power. Beginning of the season, turned off the engine i had alarms going off.
Ended up being my thermostats, when you winterize you need to run your engine with freshwater for a good 35 mins this will wash all the salt out of the stats, i brought it to my mechanic and he flushed out the stats he explained that when i winterized i didnt run fresh water long enough to clean ouit the stats i have not had an issue since .
Hope this helps
 
Johnny Dollar said:
Hockey,
That happened to me a couple of years ago. I have yammy 250 HPDI vibration and shaking and little power. Beginning of the season, turned off the engine i had alarms going off.
Ended up being my thermostats, when you winterize you need to run your engine with freshwater for a good 35 mins this will wash all the salt out of the stats, i brought it to my mechanic and he flushed out the stats he explained that when i winterized i didnt run fresh water long enough to clean ouit the stats i have not had an issue since .
Hope this helps
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I don't understand how the t-stats would make the engine vibrate and have no power. Did that happen when first started or did you have to run it a while and then it started to act up? If it overheated and then you got alarms and vibrations, I guess I can understand that case.
You also got alarms; what alarm did you get or did you just hear the alarm sounder screaming?
 
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