1998 Yamaha 225 OX66 SHUTS DOWN

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Model: S225TXRW

I have posted before when I thought this was a fuel issue since symptoms started after getting bad gas. (water) Sorry for starting a new thread but were thinking electrical now.
I have done the following for fuel:
- drained fuel tank
- new Racor 10m water seperator
- new onboard filter
- 3 new low pressure pumps
- cleaned VST tank and screen
- had injectors cleaned. (flow was acceptable spray pattern improved)
- inspected and cleaned O2 sensor with Seafoam. (a lot of carbon)

The motor will shut down, I mean like a switch was flipped. It has happend twice on hose at house in the last few weeks. Generally I will idle away from ramp take off and run for 5-10 minutes and it will cut off. If I don't run that far, after fishing or hanging in the water (hours some times), will start go for a little and shut down at idle, wait 5 minutes then it will start, and maybe you can run, maybe it will cut out. Jump up on a plane and it might take you were you wanta go or maybe not.

No buzzers or warning. (verified they function)

Now that we are looking at electrical:
- Cyl 5 has spark problems. Changed coil and same thing. Will spark sometimes and not at other times.
- Last night at dark noticed arcing on cyl 6 to bottom cowling, but firing. Today we Dbl wrapped coil wire in electrical tape and inspected all wires around area for problems. Took it to the ramp and cut out after 5-10 min on plaine. Waited till dark and fired up on hose, if you pull a boot off a plug you will see arcing back by the ECU, around your fingers (although you don't get popped by it), and random arcing around other coils.

Have noticed that most of the time it cuts out the High pressure pump will not (activate) with key in on position. Once in a while it will start back up quickly but most of the time it is a 5 min wait.

Thanks,
David
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

who ya gonna call?
ghostbusters.
you have NO issue with #5 its operating as designed.
#5 wont spark until about 2000 RPM,from about 850 to about 2000 RPM #2 doesnt spark either.
my bet is either a wirie harness issue or a main relay.
hook up a voltmeter from the from the red lead on the fuel pump to ground,any time the key is on it should show 12V.
also keep monitoring rail pressure,much below about 28PSI and it will die almost like you flipped the switch.
 

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

Thanks Rodbolt.

I will check voltage at fuel pump. I'll have to find a guage to test fuel pressure. Is that what the tire valve looking thing at the base of the fuel rail return hose to the VST is for, or do I need to "T" into fuel line comming off the pump going to the rail?

David
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

thats exactly what that schrader valve is for.
when checking pump voltage hook up to the red lead and the block. should show 12V any time the key is on.
 

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Re: 1998 Yamaha 225 OX66 SHUTS DOWN - Pressure & Amp readings

Re: 1998 Yamaha 225 OX66 SHUTS DOWN - Pressure & Amp readings

I finally picked up the fuel pressure tester. When attached to the valve its a steady 35. using the "T" fitting in the line comming from the fuel pump to the bottom of the fuel rail it was very erratic. It would show 35 with very quick drops to 23 or so then instantly back up to 35ish. We also were getting 15-17 amps at the fuel pump at Idle.

I am not sure why I was getting steady pressure when testing at the valve and very erratic readings when "T'd" into the line after the pump, but the amp reading I think I have read should only be 6-9amps. So does this mean a bad fuel pump?

As before when it shuts off, there is no voltage getting to the fuel pump. It takes 3-5 minutes before voltage will return.

Thanks,
David
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

wow now I am confused.
where did you T into anything. lost.
where are you testing pump voltage?
voltage cant get anywhere,its simply a measure of electrical pressure.
 

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

I T'd into high pressure line comming out of fuel pump to the bottom of the fuel rail. Yes, 12volts to pump, but reading 15-17amps.
David
 

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

Is the Fule pump bad?

The motor will shut down like a switch was turned off. This happens while up on a plane and at idle. When it shuts down there is no volt readings at the fuel pump for 3-5 minutes then there will be 12volts and motor will start again. So I am assuming that the ECU is shutting off current to the fuel pump.

Voltage tested while motor running at idle on the hose and fuel pump reading 12 volts.
Amps tested at idle showing 15-17amps at fuel pump.
(both readings were with the multimeter red wire connected to the red wire terminal and black wire connected to ground on engine block.)

Fuel pressure also was tested at idle. I tested two different ways (why....I don't know).
-At the pressure testing valve it read a steady 35lbs.

-I then "T"'d into hight ressure fuel line comming from the fuel pump to the bottom of the fuel rail with the T fitting that came with the fuel pressure tester. The reading at idle was very erratic. It would read 35lbs and have random split second drops to 23lbs. I did notice that with the quick drops to 23lbs and quick recovery to 35lbs the motor idle would also be erratic during those drops, so I am inclined to belive that reading.

Help and thanks,
David
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

sounds like the pump is failing, way to much current draw.
 

davidzima

Seaman Apprentice
Joined
Jan 7, 2005
Messages
31
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

OK, Thank you Rodbolt. I'll start the fund for a new one.
David
 

russelllandry

Recruit
Joined
May 15, 2011
Messages
1
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

i have a 1999 yamaha 225 saltwater series, when i use the throttle trim switch, thr engine will die if i keep it pressed. is there a short or something causeing this
 

Maxxblade

Cadet
Joined
Dec 24, 2011
Messages
9
Re: 1998 Yamaha 225 OX66 SHUTS DOWN

Did you ever find out What the problem was, I am having the same issue?
 
Top