Switched oil. Is that a bad thing?

[Mike S.]

Ever since I bought my Skeeter, I have run Quick Silver Premium Plus in it. I know, it's Yamaha powered, but I know some people with newer Yam's than mine who run it in theirs, and WAY more than I would have ever run it.

Anyways, a couple of weeks ago I went to WalMart to buy oil and they were out. I called everyone in town, and nobody had it because it was so close in price to the Optimax oil. Then the guy tells me I can get the Yamalube in bulk for around $29 a gallon. Ok, just a touch more than I was paying for the Quick Silver, but more available. So, I switched.

Upon switching, my oil reservoir had the lesser side of a half gallon of Quick Silver in it. The guy at the dealership said I would be fine mixing the two together. I was sure to ask. I have had the boat out 3, maybe 4 times since. The last time out it was a little doggy out of the hole. It felt like it was missing a little. Tonight I was out on Wolf Lake, and it was running really bad.

I am going to do a compression test tomorrow after work, and throw in a new set of plugs depending on what I find. My question is, could mixing the two oils have anything to do with it?  It still smokes like it always has, so I know it is getting oil. I have also heard that the ox66 motors are notorious for plugging the O2 sensors, could that be an issue related to mixing oils?  I'm not an outboard whiz by any means. I can work on a 2 stroke all day, but these things scare me. I sure don't want to have to rebuild that now too.

[Firefighter Jeff]

  Sorry Mike, can't help you.  Maybe I can cheer you up though.  I pay $38 for the oil in my Etec..  There, that make ya feel a little better  

[Mike S.]

Not if I have to spend $3800 for a new powerhead.

[Mike S.]

The verdict is in. I had a bad spark plug. Every plug looked awesome. What I could see in every cylinder and the tops of the pistons was beautiful. Compression is good all the way across the board. One plug was just totally black. I put one of the plugs I changed back in it and went to the lake. It ran like a raped ape!  I'm happy about that.

[Cy]

Hey Mike,

I just saw this post.  I was going to say that mixing oils would not be your issue.  I'm glad it was an easy and quick fix.

Cy

[Mike S.]

I have never mixed oils in any of my toys. I have heard stories of bad things happening, but never had any proof of it. Just seemed funny that it started running crappy after that.

[Lightningboy]

Mixing oil may have actually benefitted you this time.  A slight difference in oil make up may have helped your bad plug show itself.

[Waterfoul]

The Premium Plus is a semi-synthetic oil, as is the Yamalube.  They are very, very close to being the same oil, closer than you might think.  Our Ultra oil burns cleaner and is actually superior to the Quicksilver oil according to a blind comparison we had done several years ago.  And it's a couple bucks cheaper than either of the others.  Food for though next time you are in a bind for oil.  Ultra... I'm sure the Skegon store stocks it.

[Mike S.]

Oh yeah?  Good to know. Man, I should just post your phone number and tell everyone to call you when they have a question. Just kidding. Thanks Mike. I will keep that in mind. I am real close to out of oil right now.

[motocross269]

I would run your boat for a day and pull the plug out of the same cylinder and see if you are running rich(on that specific cylinder)......That isn't the totally correct way to check fuel mixture on a cylinder but it will give you some idea...

It was probably black because the plug wasn't firing correctily but it doesn't hurt to check...