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For anyone's info who may be interested, the oil usage of my new 250HPDI with around 20 hours now was 1.5 gallons while using 67 gallons of fuel. This works out to an average ratio of about 45:1. These amounts were consumed on a combination running and trolling fishing trip of 154 miles. The boat is a Bluewater 2350 and was heavily loaded for the trip. Seas were 2-4 feet...a lumpy day, hence I think my fuel usage was a little higher than I would have expected.
I would be interested to hear from anyone who might think that this oil usage is unusual. I haven't discussed this with my Yamaha mechanic, but when last we talked he indicated that at a recent Yamaha seminar, it was indicated to him that the HPDI will use more oil than the OX66 EFI...but that it burns less gas and is therefore more efficient.
You might want to read back a few pages, theres evidently a problem with the adjustment arm being to long. I've been running a pair for 3 months and there burning far to much, more like 35-40 to 1.
Thanks for the responses. I'll give my mechanic a call and see what he knows about a service bulletin on the oil linkage. At minimum, I can adjust the oil lever a little.
A "little" more oil is better than not enough. (as long as it is not causing a problem)! In the 50's, as a teenager, I was running 1/2 pt of oil to each gallon of fuel in Evenrudes Johnsons and Mercurys.----- Oil is cheap compared to the cost of a new power head. Before I would make any adjustments, I would do extensive research on this subject. ----Just my opinion. -----Greg
I've posted some info on this earlier, The one thing to ask your mach. about is the use and ratio of Ring Free. They are now recommending 1 oz. to 10 gals. This is an increase of ring free to compensate for the extra oil. It is still one of the nices engines I've run, but the extra oil is a pain.
Bill...
You know there is a problem with our motors. the oiling arm is too long and resulting in too much oil ussage. Yamaha is aware of this problem and making a new oiling arm that will be covered by warranty.
According to my Yamaha mechanic who just got off the phone with the Yamaha tech rep, here's the skinny on this subject:
My oil usage (45:1 on a combined trip of running and trolling) is not unusual. Even 30:1 is not uncommon. Because these engines use less fuel, the oil usage expressed as a ratio to gas consumed will be higher.
The oil linkage arm should be checked to make sure it is 0.5mm off the stop at idle. (This compares to 1.0mm for the EFI OX66 engine). If the arm cannot be set to this clearance, there may be a problem with the arm's length...if so, then it's time to check back with Yamaha. He has seen no bulletin on the subject of the oil linkage arm length as of yet, but will continue to look for them. Just "eyeballing" my linkage, I think it is currently more than 0.5mm. If my measurements confirm this, I'll adjust it a bit...but only a little bit at the time...and continue to monitor oil usage.
Yamaha does indeed now recommend 1 ounce of Ring-Free to 10 gallons of fuel (vice 1 ounce to 15 gallons).
So I bought the latest, greatest technology.....and i get to burn more oil and now I'll add an additional
30-35 bucks a trip for Ring Free.....I am so happy !!
Maybe now, gas will get to 4 bucks a gallon and it will cost a cool grand to fish the stream......as i said before, if you have a sweet running 250 OX66
KEEP IT !!!!!
My mechanic indicated that there is apparently some minimum amount of oil required to keep these engines lubed, so as fuel economy increases the proportion of oil to gas increases. This makes sense since the number of times the engine turns over to take you from point A to point B is approximately the same, regardless of the fuel it takes to get you there. I'm not crazy about my 45:1 ratio and expect I may be able to get it up to 50:1 or slightly better if there is still adjustment left in the linkage while still staying at or above the 1/2mm recommended gap. My friend's OX66 250 on the identical boat is running at an average 50:1 ratio.
I'm also not especially happy with the "supposed" fuel economy of this engine. My 2.28mpg on the last trip is not significantly better than my buddy's 2.2mpg on the same trip, although he was carrying a lighter load (250# lighter) and running without tabs.
On the subject of oil cost, providing you have the storage room, buying a drum of oil with a buddy can help reduce the cost. That's what we do.
every big block yamaha i have seen is an oil hog.most of what i have seen & read about says the ox66 typically get 35:1 on average.most of the hpdi's get around 50:1.my 200 hpdi's avg close to 50:1.
Yamaha 250HPDI Oil Usage 
