Merc Premium Plus blend at $20/gal. reg price from a Merc dealer. Yamalube, v. -the act of having your sphincter lubed just prior to checkout at your local dealer. Ouch $38/gal. That would have me rethinking that stuff too capt. Pete.
I do know that Merc. Premium Plus and DFI oil mix without a hitch. Had to do it to get home once, everything worked out.

In my towboat I run optimax oil exclusively. But I don't have to pay for it. I double checked the price of Yamalube at my marina. List price is $34. But even with my discount it can't beat the Penzoil. Plus with the Yamalube I have to use ring free or I will foul plugs over time. I was told by others that had the same problem that also switched to Penzoil and they never fouled a plug again. I figure with my old motor it's worth a shot.

I have been using wally world oil for years!! Even now with a 2004 Yamaha HDPI, never a issue! If you are under warranty use what they say, but all bets off after warranty is gone!

I would NOT use wally world oil in a HPDI unless you want to have a costly engine repair. HPDI engines have a MUCH different oil requirement, and improper oil is what lead to the majority of early FICHT failures as well as MANY optimax engine and compressor failures.

You can either chose longevity on your investment or not.

My engine has a setting for the XD100 that allows you to burn less oil---one way or another you pay!

Yes I pay around $38 a gallon for my oil and am lucky to burn 5 gallons a year at around 400 hrs a year. Cheap insurance on a $15,000 motor, IMHO.

The lack of oil consumption using the XD100 is crazy good. I agree that it would be foolish to risk a powerhead by saving a few bucks on oil. Penzoil would be my go to stuff on premix motors. I met a go fast dealer in Florida that swears by the Wally World oil in his Opti's. And he could afford to pay for whatever oil he wanted. He believes it to be a better product. ???

I used to run two stroke oil 200:1 in my 6.5 diesel. When i first started it, I had some Xd30 and run that. My mpg went up 1mpg. Then i ran out and bought wallyworld oil. Mpg went back down 1mpg. I was trying to save my injection pump till tax time. That goes to show that you really get what you pay for in oil. My injection pump was fine. Turned out all three nuts were loose and it was rotating a little bit and overfueling the engine. For a while my V had a soot black bow on the starboard side. I did replace the pump and been running OptiLube xpd ever since. The xpd gives me 1mpg more just like the xd30. Only the xpd costs $28 per quart shipped from cali. I have already bought a gallon of Merc oil for my 2.5l. That is all i plan to run in it. To me its worth the peace of mind k owing i have a manufacturer recommended oil and i wont be cheap when it comes to two stroke oil. That oil the only thing keeping your engine running and 40+ miles offshore i prefer the peace of mind.

New member here but a long time powersports junkie; snowmobiles, 4wheeler's, boats, etc. I have run Amsoil exclusively in all my motors for years with great success. Specifically in my pre mix 2-strokes, I run Amsoil Saber or Saber Outboard and mix it 100:1. My '86 225 VRO, (minus the VRO, hence the premix) runs smooth and fast with almost no stink and no smoke and I have over 300 hours since the last ring job. At $36 a gallon it is the same price mixed 100:1 as the petroleum based everyday TCW-3 oils mixed 50:1, and it is a far superior oil, in my experiences. Just another option for synthetics...

I found your problem.

I use Pennzoil but not the sythetic stuff. It is the one called XLF. About $20 /gal. I am running a 150hp Yamaha 2 stroke oil injection with around 500 - 600 hours.