Looking for Info on 2003 OX66 200HP

[basshole51]

Hey all,
I am looking at a boat for sale with a 2003 Ox66 200 hp on it. I am not very familiar with Yamahas so I was hoping someone could provide some inside on what to look for and common wear issues on motor. Motor has 200 hours and owner stated he always runs Yamalube and Ring Free. What should I look for for compression numbers? What are common wear items? Anything particular to look for on these motors besides the basic stuff? To my knowledge these are pretty stout, bulletproof motors that are fairly simple to work on...correct me if I am wrong.

[98skeeter202]

There is no way to get hours off my , he may have added some type of electric meter. IMO the 0x66 is one of the best ever built!

[basshole51]

I should add that this bost is equipped with the Yamaha digital gauges that reads 203 hours.

[Mr.Miyagi]

COPY THAT

There is no way to get hours off my , he may have added some type of electric meter. IMO the 0x66 is one of the best ever built!

[basshole51]

SO I cannot confirm engine hours (besides the Yamaha digital gauge on the dash)/...what are standard compression numbers on a motor like this ?

[ClarkBird]

SO I cannot confirm engine hours (besides the Yamaha digital gauge on the dash)/...what are standard compression numbers on a motor like this ?

100-110psi

[basshole51]

Thanks! Does anyone know if there is a thread on here containing common maintenance for these motors? I have been doing some reading and it appears they have fuel filters that need regular changing along with o2 sensors that need regular decarbing, also fuel injectors that need regular service.

Current owner stated he just replaced all filters and always runs ring free.

what kind of PSI do these motors need ? My Mercs always only needed 15 PSI

[CJ1]

PSI as in water pressure? Mine was happy at 7-10 with the stock lower but since I have had the HPDI lower it usually runs 20+ unless really airing it out then I try to keep it at 10 or so. Injectors are no different than any other engine, if the fuel is clean and fresh they are very reliable. The 02 sensor and draft tube should be cleaned every year and normally not a issue with synthetic oil and ring free or sea foam. Filters in the VST and the main fuel filter is also directly related to the condition of the fuel and running a prefilter. I serviced my VST and checked float height just because I had my injectors cleaned and calibrated and it was spotless. Had not been touched after Hydro tec built the power head 4 years ago. CJ

[basshole51]

yes Water Pressure....so 7-10 PSI is minimum at WOT then ?

[basshole51]

serial number is VX200TLRB

[basshole51]

talked to seller and he says 35 PSI at 4K RPMS....does this seem right? Also what is the recommended WOT RPM range for these motors?

[CJ1]

talked to seller and he says 35 PSI at 4K RPMS....does this seem right? Also what is the recommended WOT RPM range for these motors?

Yep, mine runs in the high 20 until I start getting it aired out. The limiter I believe is at 6250 or so and I run and prop mine at 6k.

[CJ1]

yes Water Pressure....so 7-10 PSI is minimum at WOT then ?

I think yam says 15 but from experience with my engine and a bunch of hpdis they are fine at 10. I ran my 150 hard and when I slowed down forgot to trim down and barely had any pressure for a few minutes and it did not over heat. That is the only bad thing without a low water pickup. That is the main reason I put a hpdi lower on my engine. Cj

[basshole51]

I think yam says 15 but from experience with my engine and a bunch of hpdis they are fine at 10. I ran my 150 hard and when I slowed down forgot to trim down and barely had any pressure for a few minutes and it did not over heat. That is the only bad thing without a low water pickup. That is the main reason I put a hpdi lower on my engine. Cj

thanks CJ1. I have been doing some research and a couple places I have read that these motors clog easily from vegetation...would the HPDI lower alleviate this a bit as well?

[CJ1]

thanks CJ1. I have been doing some research and a couple places I have read that these motors clog easily from vegetation...would the HPDI lower alleviate this a bit as well?

That I don't know, never had a issue with that. Cj

[201pro]

I run the HPDI lower unit and the only time I have ever had an issue is in really mossy slop. But it clogged everyone a lower unit no matter what brand.