I just purchased a 2014 Fisherman 230 with only 167 hours on a 2014 yamaha 300xca,,, it was used near VA beach where the marinas use ethanol fuel,,, I live in Ocean City Md ,, where marinas have non ethanol which I have used in all previous boats. During sea trial in Norfolk VA the engine performed flawless, also when put in water here also run flawless until I filled tank with fuel to mark the water line for bottom paint. Shortly after fueling boat we were headed back across bay at about 3700 rpm when engine shut down abruptly,,, it started right up and got back up to same rpm and did it again . This happened 4 times. Made back to slip ok,, next mourning I went to boat and I felt the primer ball and it was soft,, I tried squeezing ball it did not get hard. Took boat out with my wife for a 1 hour cruise and it ran perfect. Next I marked the water line and had bottom painted and replaced the primer ball ,, when put in water could not get Yamaha ball to prime,, had an old mercury ball and used it and was able to get line primed. Next day I had 6 people and board and had no problem ( however much of the time was idling in no wake zone ).. Next evening went out with my wife and son and started happening again and noticed that when it happened the ball went soft. Replaced line from water seperator to ball ,, still had problem . I am convinced the problem is on the tank side of seperator,, any Ideas,, just spent alot of money on this boat and going CRAZY !!!!
ABRUPT STALLING AT ABOUT 3700 RPM
- Thread starter moondog58
- Start date
I assume the primer bulb didn't collapse.
My first thought is that there is an air leak that makes it hard to prime and when run at speed, doesn't allow enough gas to get sucked up.At speed under load. gas used up faster than the fuel bowls fill and in effect you run out of gas.
Check that all filters are seated correctly.( on motor filter and water separator,)
My first thought is that there is an air leak that makes it hard to prime and when run at speed, doesn't allow enough gas to get sucked up.At speed under load. gas used up faster than the fuel bowls fill and in effect you run out of gas.
Check that all filters are seated correctly.( on motor filter and water separator,)
I had a similar experience with a Marlin - turned out that a fuel hose had delaminated and choked off fuel flow at higher pressures. Unusual, but happened to me!
wrxhoon
Well-Known Member
I know it sounds like fuel problem but don't discount spark plugs, one could be failing under load . Have you changed them recently? Plugs are cheap and they don't last forever, I would replace them, easy to do, see it the problem persists.
Did you change the fuel/water separator? I would also check the fuel/water separator to see if you have water in the fuel tank/tanks.
If there were enough water in the fuel filter and/or the water separator to actually stall the motor, it would not restart until the water was drained.
wrxhoon
Well-Known Member
You are right, I din't read it properly , I took it that she wouldn't rev above 3700.
Looks like a fuel related problem
Ling king
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I'm having a similar issue. I have twin 2001, 200 yamaha 2 stroke with 550 hours on them. At high RPM's the port side engine would bog down to 1000 RPM's and appear to be starving for fuel. Even at full throttle there is no difference. I swapped the gas lines and the same problem was happening to the same motor. Therefore the problem is in the motor. I replaced the water separator filter, the fuel filter and the VST filter. Even added Yamaha ring cleaner fuel additive. I took the boat out today and at 2400 RPM's the same problem occurred. I let it idle for a bit and it would run like a champ for about 5-10 minutes and then back to starving for fuel.
Not sure what is next. Spark plugs have also been replaced. The motor starts every time and idles great.
What do you think? Injectors, high pressure fuel pump, gas lines? The gas lines look really good.
The boat is almost complete. I need to find this evil bug. Any ideas????
Not sure what is next. Spark plugs have also been replaced. The motor starts every time and idles great.
What do you think? Injectors, high pressure fuel pump, gas lines? The gas lines look really good.
The boat is almost complete. I need to find this evil bug. Any ideas????
Check the tank vent plumbing although a plugged vent would affect both motors. Does the primer bulb collapse?
Next time run the motor till it dies and immediately turn off the ignition. slow to a stop and pull off the cowling to look at the clear gas filter bowl. It should have gas but not be completely full. Of course if it is very low that tells you there is a fuel delivery issue. If completely full you may have an air leak.
When you changed fuel lines, what exactly did you swap?
Next time run the motor till it dies and immediately turn off the ignition. slow to a stop and pull off the cowling to look at the clear gas filter bowl. It should have gas but not be completely full. Of course if it is very low that tells you there is a fuel delivery issue. If completely full you may have an air leak.
When you changed fuel lines, what exactly did you swap?
Which Fuel filters did you replace? i believe you have the seperator filter, low pressure filter, and medium pressure filter. Then you have those mystery or hidden filter In high pressure pump and injectors. Could be a fuel pump if you pump the bulb on the motor at the dock if you see a fuel sheen in the water low pressure fuel pump could have a punctured diaphram. VST pump could Also not be pumping. I’ll guess you need the expensive medium pressure filter.
Ling king
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I swapped the gas lines from motor to motor at the bulbs to confirm that it's not a fuel delivery issue. The problem was still with the same motor.
Ling king
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I replaced both of them. I really thought that was the problem. When I removed the old filters, they sure looked clean. Problem still persist. Randomly
You swapped fuel lines at the motor end of the bulb? That would eliminate a lot of sources. The actual engine fuel line and all the pumps, motor filters etc could still be a cause. Did you check the motor mounted gas filter to make sure the bowl is seated correctly" Do that first.
Also can you tell us what exactly happens when the motor dies?
Do it stutter, run rough and die or is it more like you turned off the ignition?
Does it restart right away or does it have to sit for a while?
When it dies, is the primer bulb firm or soft?
Have you noticed if the problem is more likely to occur when the boats is pounding more?
There are several potential areas that can cause the motor to run out of fuel at certain loads. Often though the motor will start to run rough or surge first.
There are elctrical things that can cause the shutdown also. Some may be related to ho warm the motor gets under the cowling. Those types of faults often result in a shutdown like the ignition was turned off.
It may be possible to determine which class of issues your's falls into by using a fuel pressure gauge on the output of the high speed pump. It is a bit tricky and probably needs a helper but basically you connect the gauge, leave the cowling off and watch the fuel pressure. If the pressure starts to lower and then you stall, that makes some things more likely. If the motor dies but the pressure doesn't (at least at first), the problem may be electrical.
Also can you tell us what exactly happens when the motor dies?
Do it stutter, run rough and die or is it more like you turned off the ignition?
Does it restart right away or does it have to sit for a while?
When it dies, is the primer bulb firm or soft?
Have you noticed if the problem is more likely to occur when the boats is pounding more?
There are several potential areas that can cause the motor to run out of fuel at certain loads. Often though the motor will start to run rough or surge first.
There are elctrical things that can cause the shutdown also. Some may be related to ho warm the motor gets under the cowling. Those types of faults often result in a shutdown like the ignition was turned off.
It may be possible to determine which class of issues your's falls into by using a fuel pressure gauge on the output of the high speed pump. It is a bit tricky and probably needs a helper but basically you connect the gauge, leave the cowling off and watch the fuel pressure. If the pressure starts to lower and then you stall, that makes some things more likely. If the motor dies but the pressure doesn't (at least at first), the problem may be electrical.
Ling king
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Yes, I swapped the lines at the motor end of the bulbs. The fuel filter is properly secured.
The motor doesn’t die. The rpms start to die down and drop to 1000 rpms. Full throttle and it stays at 1000 rpms. No difference if it’s running at 2000 rpms or 5000 rpms. But mainly does it at higher rpms. No difference if rough seas or smooth. No evidence of overheating. Air and water temperature were at 70 degrees.
What do you think?
The motor doesn’t die. The rpms start to die down and drop to 1000 rpms. Full throttle and it stays at 1000 rpms. No difference if it’s running at 2000 rpms or 5000 rpms. But mainly does it at higher rpms. No difference if rough seas or smooth. No evidence of overheating. Air and water temperature were at 70 degrees.
What do you think?
That info changes things a bit. I am somewhat stumped. Normally that symptom would be related to a clogged VST filter but you said you changed it.
The only diagnostic thing I can think of is the fuel pressure gauge test in addition to shutting down immediately after the drop in revs and checking the clear fuel bowl assuming you have one.
I found two references to a problem similar to yours. One claimed the issue to be dirty injectors but that doesn't feel right to me.
The second was on a F250 I believe where a can sensor was bad.
I think you are going to need a good mechanic with experience on the 300.
The only diagnostic thing I can think of is the fuel pressure gauge test in addition to shutting down immediately after the drop in revs and checking the clear fuel bowl assuming you have one.
I found two references to a problem similar to yours. One claimed the issue to be dirty injectors but that doesn't feel right to me.
The second was on a F250 I believe where a can sensor was bad.
I think you are going to need a good mechanic with experience on the 300.
The cam sensors throw a code, even if intermittent. I'd get the YDIS diagnostic software and see what it says when the engine stalls. I agree that the VST is most common. Could be an LP or HP pump, but those typically are not intermittent. Get the YDIS for $60 on ebay and watch what happens. I believe it works on 2014 models, but you'll need to check that. On that engine the LP and VST filters are pretty hard to get to. Are we sure they were both changed? How did the inside of the VST look when you took it apart? So all four filters looked clean?
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