What 2-stroke oil for carbureted Merc 150?

[NWFisher]

I'm trying to reduce the smoke from my year 2000 merc 150hp carbureted 2-stroke. I decarboned the engine with seafoam by mixing it with a gallon of fuel, running the engine for 15 minutes, letting it sit for 15 minutes and repeated three times. The engine seems to run a bit smoother and there's an oily/blackish mess left on the ground from the exhaust. It was cold so there was lots of steam/smoke mix and hard to tell if the smoking actually reduced. I did it three times because it's said no one had to do it more than that to decarbon.

I've been using quicksilver premium 2-stroke (no containers left so time to buy again) and the several gallon tank on the boat is full. Is it better to use 2-stroke synthetic oil to reduce the smoke? Merc oil? Amsoil? Is it okay to add synthetic to the existing oil in the tank? All suggestions/comments are appreciated!

NWFisher

 

[frankie g]

Re: What 2-stroke oil for carbureted Merc 150?

hey nwfisher glad to see you decarboned! I've been running Penzoil full synthetic, and I use Star Tron in my gas all the time and add w/ any addition of gas, and I decarbon every 75 - 100 hrs or so...some say every 50 hrs. but with this combo my engine runs fine and smoke to a bare minumin. buy the way the 150 classic can run all day long WOT and loves it! so jump on her, that also will keep the carbon build up down. That engine has been around for ever and is probaly there most reliable engine...practicly bullit proof. I'm not easy on mine, I run her HARD, WOT alot! When I go fishing sometimes I have a 1-2 hr run so I like to speed up the run out and back in.

 

[NWFisher]

Re: What 2-stroke oil for carbureted Merc 150?

Thanks Frankie! I knew you'd reply. Yeah, I got-r-done. The rains, cold and snow stopped and I had a few hours so toyed with the boat. It's one of my great pleasures except the waxing until it's done anyway.

I agree, it's a great motor and if I can get the smoke smell under control I won't trade for something new. $15K is, well, $15K that could go elsewhere. I'm going to take it to "my shop" in the next few weeks for a professional physical. I run it hard too and WOT is the way we go as seas permit of course. That's one of the reasons I like Lake Roosevelt because I can really open it up versus Puget Sound where speed is usually dictated by the sea. I'll run it WOT for long distances without concern. It runs well, just smells sometimes.

So I'm looking for penzoil. I guess you found it better than merc synthetic (I assume they have something)? Obviously I'm looking for a TCW3 synthetic.

Thanks Frankie.

P.S. Let's talk props one of these days.

 

[SpinnerBait_Nut]

Re: What 2-stroke oil for carbureted Merc 150?

Non-Repair Outboard Engine Discussion

 

[tashasdaddy]

Re: What 2-stroke oil for carbureted Merc 150?

any of the full synthetics that meet the TCW 3 qualifications are fine. i've used walmart brand, for years.

 

[frankie g]

Re: What 2-stroke oil for carbureted Merc 150?

You should put this thread BACK in the Trophy section! He HAS a TROPHY and is asking TROPHY owner a detailed question, if you were to look at it that way there would be few threads in any section!

 

[frankie g]

Re: What 2-stroke oil for carbureted Merc 150?

nwfisher, hey Glad to give any assistance I can! Just remember though,...it is a 2 stroke and there's gonna be some smoke and smell.
PROPS ! Oh boy, I know nothing about them. I'm pretty satisfied with mine but at the prices of them, to be buying and trying them, just to get a little more out of your speed or gas kind of keeps me away from the whole thing. I am in the range of rpms at WOT, 5600-5800 so I just stay with what I have, I'm not into the speed thing any more, I cruzie at about 24-26 and WOT anywhere between 30-34, thats fine with me and gas consumtion ranges from 2-3 mpg, of coarse all depends on the wind, current, and sea's. I still even use the aluminium prop that came with the boat! Hey! have a good one.

 

[lyle]

Re: What 2-stroke oil for carbureted Merc 150?

I am not sure about 2-stroke outboards...all I have ever used is 4-stroke or inboard motors but I grew up on dirt bikes & the one cardinal rule was to ..........NEVER.... mix synthetic oil to existing conventional 2 - cycle oils.... it is ok to empty the old mixture & refill with the synthetic , but I would not combine them.

 

[frankie g]

Re: What 2-stroke oil for carbureted Merc 150?

I don't know about the rest, but I called Penzoil last yr. and they said that I could mix with there oils...they have synthetic blend as well as full syn. and said if I mixed reg. with any of there syn's it would be fine, ( like making your blending your own syn. blend.) Like I said...that's Penzoil. I just dropped my lower unit to put in a new water pump, and I also took off my prop to clean it up and grease the spline and couldn't believe the inside of my threw prop exhaust !!!! almost carbon free !!! just about enough soot to on my finger to notice it was present, 98 % carbon free, and that's after my last cleaning and greasing, approx 75 hrs ago. I must be doing somthing right. ( knock on wood )

 

[NWFisher]

Re: What 2-stroke oil for carbureted Merc 150?

Sorry for the delay in postings. There's this thing called WORK that gets in the way of LIFE.

The boat is with Dr. Mechanic who has earned my trust so I should be hearing his findings in the next few days. The engine runs fine just seems to smoke excessively. Anyway, he's giving it a thorough checkup and give an estimate of any repairs/improvements that might be needed. Depending on the estimate I may decide to buy a new engine then all this talk is for naught. I'm told a new merc 175 opti is about 20% quieter and 40% more fuel efficient and that speaks loudly to me. That means at least 40% more oil efficient too and probably a LOT more. At like $250 for a tank of gas and another $50 for oil, 40% improvement turns into real dollars. We'll see.

He also said that since the engine was built there are changes to the oil system (pressure valves, etc.) that will reduce the oil use rate and reduce the smoking. Again, more to come.

Lastly, it appears penzoil fully synthetic is pretty good stuff but then others say even Walmart oil does the job. Here too, more to come based on the estimate.

NWFisher

 

[frankie g]

Re: What 2-stroke oil for carbureted Merc 150?

I use Wally world full syn. oil in my vihicels, I've read it's just as good as Moble 1....but I haven't found any lit. on there marine 2 stroke syn. so I haven't used it. And a new engine is nics but the cost isn't it'lltake alot of fill ups to justify the saving. But if the money is not a problem and you want one....GO FOR IT! clue us in.

 

[NWFisher]

Re: What 2-stroke oil for carbureted Merc 150?

I picked up the boat and the mechanic's findings but the following day had to take a business trip to Lima, Peru and will return home this coming Saturday (just two more days!).

The mechanic says the engine is in great shape with low hours and believes it will deliver many more years of service. As I recall they changed a back pressure valve, another pressure valve and the oil pump link rod was out of adjustment. Now runtime is needed to know if it burns less oil and smokes less.

If forgot to ask his thoughts on 2-stroke oil but I know he sells Quicksilver 2-stroke premium from his drum so I suspect that would also be his recommendation. I'll do some fact-finding before I decide to change oils.

Anyway the engine stays as does the $15k earmarked for it's replacement! I'm looking forward to being home and on the boat again.

NWFisher