'00 Yami OX66's

[Cricket Too]

Hey guys, looking at a boat with twin '00 Yami OX66's. Engines are clean as can be, and have about 170 hours on them, they look brand new and run perfect.

Just looking for any opinion or any facts on these engines. Been OMC my whole life but was always impressed with Yami, and these are very nice engines.

Thanks.

 

[rodbolt]

Re: '00 Yami OX66's

good engines, my worry is the maint has not been done.

 

[Cricket Too]

Re: '00 Yami OX66's

Hey rodbolt. The engines have been taken care of by the same yard that it's in right now for it's whole life, very professional shop. The manager had a file of everything that they have done over the last 6 years. Mostly PM stuff, some minor repiars.

I could tell just by looking at them that the t-stats had been replaced, I could see the gasket sealing compound still fresh around the housings, water pumps had just been done also. They only have 170hrs on them in 6 years, so they didn't get used all that much.

One question I did have on these was about the oil resevoir on the engine. Is this used for emergency purposes, or is it used for normal running lubrication and just gets replenished by the remote tank? I saw a switch on the back, that was for emergency purposes, but wasn't sure exactly how that worked either.

Also these engines being EFI, is oil injected separately from fuel, like in DI, or is it combined first and the mixture injected down the manifold?

Thanks.

 

[Ray Neudecker]

Re: '00 Yami OX66's

The engine mounted tank is used for running lubrication and replenished from the larger boat mounted tank.

 

[rodbolt]

Re: '00 Yami OX66's

on the OX66 the oil is fed from the 6 pump nipples to a common manifold and through a check valve to the VST.
my worry is the VST and O2 sensor maint hasnt been done due to the low hours.
the maint schedule is set up for hours OR a calander period.

when the level in the remote tank gets low you will get a yellow lamp on the tach,and NO automatic oil transfer. there is enough left for about 2 manual transfers.

 

[Cricket Too]

Re: '00 Yami OX66's

Thanks for the info guys. Rodbolt I will check to see if the maintenance has been done on these two items.

Just so I know, what exactly is the VST?

 

[reeldutch]

Re: '00 Yami OX66's

vapor seperator tank.

gets the fuel from the lift pump(s)
releases al the vapor back into the airbox.
gas is being mixed with the oil. its a regular EFI not HPDI.

cricket since you are from long island be very carefull, there has been a lot of bad gas problems this last year.

the Ethanol is on long island a big problem.

it will clogg up filters, seperate fuel/water and burn out fuel pumps.
I just want you to be aware of the situation.

i know a realy good mechanic specialized in yammies.
his marina is in seafort.
drop me a E-mail and i will get you his number.

he can help you out.

 

[Cricket Too]

Re: '00 Yami OX66's

Thanks reeldutch, yeah I have encountered some problems with the Ethanol. When it first arrived 2 season ago, I went through about 6 fuel/water separators in one season. Haven't had a problem since, but I currently have a metal fuel tank. There was a guy in my marina that had a fiberglass tank, and he had major problems, but he has a DI motor which made it even worse. So I made sure this boat had either a metal or plastic gas tank, so I don't get involved with what ethanol does to fibergalss.

I also heard from a local dealer that the Ethanol content in the fuel is way higher than the 10% they claim is in there, which is why we are having so many problems, more like 20%. They have also found that other than the ethanol causing the fuel to separate, it lowers the octane on it after it sits and separates, so it's not a bad idea to fuel up with 93 before and after sitting for the winter.

 

[reeldutch]

Re: '00 Yami OX66's

yep,

i heard from different dealers that there was as high as 30% ethanol blended.
it seems strange because the production of ethanol is still more expensive than gas. so why would they add more if its only 10% requierd.

phase seperation also happens in your vst thats why you should add fuel stabilyzer before resting the motor.
the high pressure fuel pumps do not like to pump water they will burn up.


i do not know about the O2 sensor maintenence.
it sound s like this is a closed loop system?
the O2 sensor gives feedback if the motor is running lean or rich and the ECM makes adjustments on that information.

my advice get these motors checket out by a factory trained mechanic.
its imposible to repair them yourself without the knowledge and special test equipment like a winky blinky.
tps has to be set etc etc.

if you want i will give you his number he will be happy to help you.
its slow now any way.

 

[Cricket Too]

Re: '00 Yami OX66's

reeldutch, Seaford is a little tough for me to get to, since the boat is too big to trailer, but I'll take his number anyway.

What exactly needs to be done to the O2 sensors and the VST? I have all of the maintenance records available, so I can check to see, and also ask about it.

Thanks.

 

[reeldutch]

Re: '00 Yami OX66's

[whisper uid=23216]

Enter private whisper here

[/whisper]

his name is Scott he is the Marina owner and a very good Mechanic.
Alhamra Marina
phone 516 - 785 - 2080
he is always willing to explain things.
he is also a part time teacher.

 

[Cricket Too]

Re: '00 Yami OX66's

Thanks reeldutch, good to have as an option.

 

[rodbolt]

Re: '00 Yami OX66's

the O2 sensor set up on the ox66 is a closed loop system, its not desined to run in open loop.
if the sensor is unplugged it will fix fuel rich at low speed and lean above 4000,operation above 4000 is not reccomended.
if it fails the ECU wont see it and may go lean above 4000 causing piston failure.
make sure its maintianed and working correctly.

 

[reeldutch]

Re: '00 Yami OX66's

see, thats why you should get it looked over by a good yammi wrench.

there is no way you know how the motor runs without a prooper diagnose.