Problem on idle - 2000 Yamaha SX 150 TXRY EFI OX66

[retdguy]

Hi,

I'm hoping someone can offer some help or suggestions ...

I'm having a problem on idle up to about 1800 RPMs where the motor seems like it's loading up a bit. As soon as I push the throttle up, it clears up and runs fine. I had it running at 3500, 4000, 4200, 4500, 5000 RPMs and it ran great.

As far as maintenance, this is what I did this year:

• Replaced VST filter
• Replaced all spark plug caps
• 2 new low pressure pumps
• New pressure relief valve
• New water pump
• 2 new thermostats
• Cleaned O2 sensor which looked fine - had a little carbon on the O2 sensor and the draw tube was a little oily but clear (no blockages).

Late last year I did the following:

• Replaced VST filter and engine filter

Every year I replace the 10 micron water separator filter and spark plugs.

I only put about 50-60 hours on it per season.

Also, today I noticed on my Yamaha gauge that the battery was registering 12.6 and it was blinking on and off. Is this too low? I have 2 batteries ... one is a brand new (this year) starting battery, the other is a deep cycle battery group 24s.

The engine mounted filter looks clear. I purchased the boat used about 3 years ago so I don't know what maintenance was done before I got it.

Any help or suggestions would be appreciated.

Thank you.

- Bob

 

[rodbolt]

Re: Problem on idle - 2000 Yamaha SX 150 TXRY EFI OX66

check the fuel rail pressure,check the O2 sensor output voltage test the stator low speed output voltage.
if avalible run it with a diagnostic test lamp at the problem RPM.

 

[retdguy]

Re: Problem on idle - 2000 Yamaha SX 150 TXRY EFI OX66

Thanks Rodbolt. I was hoping you would answer. I'm no outboard mechanic so I'm a little intimidated by these digital volt meters as I've never used any. Can you recommend a good fuel pressure gauge and digital volt meter so I can perform these tests? They don't have to be top of the line ... just something halfway decent.

Rodbolt, I noticed when I come back - I flush the engine out in a 55 gallon drum for about 10 minutes and I noticed the smell from the engine -- it's very strong and gives me a bit of a headache if I stay near it while washing the boat. Although the boat is kept outside, it is in a bit of a confined area (close to the garage door).

Thank you.

- Bob

 

[rodbolt]

Re: Problem on idle - 2000 Yamaha SX 150 TXRY EFI OX66

a decent digital voltmeter can be had at radio shack or sears for less than 30 dollars.
the fuel pressure test guage is about 70 but a lot of auto parts stores rent them.
its the small sharder just like a bike tire.
also check your coolent temp sensor.
can be tested with the tune up spec guide or service manual and the digital meter.

 

[retdguy]

Re: Problem on idle - 2000 Yamaha SX 150 TXRY EFI OX66

Hi Rodbolt I will p/u the equipment needed this week .


Thank You
Bob