Chevron and Merc outboards?

[rickd]

I blew up my Black Max 150 a month or so ago and don't want to deal with this in the near future.

It's at Boatmasters now getting a XR4 150 strung on the back.

I met this guy up at CL this past weekend and he said that you must use mid grade Chevron gas or I will have issues again? I asked him if he had Chevron stock, he didn’t.

Any truth to this?

[basstamer]

Sounds like BS to me-did you ask the mechanics when you took your boat in? What was his reasoning behind saying that I wonder? I use the cheapest gas I can find just like in my truck. I at one time use to fill up with premium and pay the extra large bucks but when I bought my new boat they said that you need to use the low octane gas as to not hurt the engine so I dont think this guy knew what he was saying.Maybe he didnt have stock but worked for them! Tight Lines and good luck with the new motor!
Scott

[krpierce]

The guy I bought my boat from told me the same thing? My dad had a Yamaha that he ran the cheapest stuff he could find in and he had zero problems for the 15 years he owned the boat. I would like to know what the guys on the forum think???

[jbsteels]

I run 87 octane in my 225 optimax and have not had one problem. What i have been told by both mercury and dealerships is that they say to use the low octane for two reasons. One, you are just wasting your money on the high octane gas, because these motors are made to run on low octane and two, the high octane burns hotter in these motors and can c ause motor failure.

I use what is recommended by the factory. They say to use optimax DFI oil in these motors, you can use premium plus for a cheaper price, but it is recommended to use the DFI oil, so that is wat I use. Always use what is recommended by the factory especially for warranty reasons....

Just my .02

Justin

[492slayer]

The 87 Octane rating is recommended because these motors don't have the higher compression needed to run the premium fuels. I have to run 91 or better in mine because I run a lot higher compression than the stock opti's and EFI's.

[rickd]

I wish I had an Opti but we're talking about a 1990 150 XR4. The guy was pretty sure of himself and was adamant about it.

I have a hard time with that because I don't have a tow vehicle and have to use Lazy M gas which is 89. Price isn't to bad, they are at 3.50 a gallon.

[MIKE TREMONT]

And some peope have a shot of whiskey and one smoke a day and live to 100.
I'll share my experience and why. I raced watercraft, to be competitive you have to be willing to take things to the edge. If you can make the fuel /air mixture as lean as possible and not have your engine gernade on you have been successful.
As I understand it the higher the octane rating, the COOLER it burns, not like in the previous post. I'm pretty sure your motor is carburated and there is no computer involved.
With these newer engines that are controlled by the computer there is a lot less risk. It does all the mixing for you. It senses octane and oxygen levels and makes adjustments accordingly. You don't have that luxury.
Chevron's octane levels are more consistant than some of the others, and it has additives that help keep things clean.
Carbon build up is another enemy. For my money (and I'm frugal), the higher octane and some type of carbon cleaner and regular maintenence is your best insurance.
Just my .02

[MrSkeeter]

Well, this was a topic of discussion I had w/ many a few years ago. Back then it was should we use PREMIUM or not. Anyway, the conclusion was to use mid-grade (rather than Premium) ... the reasons are this ..

All grade of gas are basically the same when they come out of the factory. The different grades simply have different additives ... the premium have more additives and extra octane booster added to them. However, some the the additives (detergents) could *possibly* degrade the oils used in 2 stroke motors to help lubricate the engine. So it was simply a safe bet to just use mid-grade.

I suppose one can also use regular unlead as well. Just that our motors are really performance motors and you really want the higher octane in the mid-grade.

I for one, have been using mid-grade cheveron whenever I can. But I use Union76 and Shell (in that order) ... because I've always had good luck w/ Cheveron. I also add octane boosters (on occasion) to the fuel and now am trying the SeaFoam that was recommended from my previous post. Just a peace of mind I guess.

[Dewayne]

I prefer to use Chevron. There are a few issues when dealing with fuel.

Octane just controls how fast the fuel burns. If the motor has high compression and/or advanced timing you need higher octane to slow the fuel burn and keep destructive pre detonation from happening. Burn that is recommended by the manufacturer for octane. Burning higher octane will not improve the engines performance.

Additives - This is why I burn Chevron. Their Techron additive does a good job of reducing carbon deposits and keeping the rings working free. You can burn cheap gas and add your own additives. Too much carbon buildup can cause engine failure. When you add the cost of the additive the cheaper gas may not be much cheaper.

Other things to consider are water in the fuel and freshness of the gas. Some cheaper stations are fine, some are not.

[troutnut]

In my old 1982 Merc 200hp v-6 motor, the guy i bought it from told me to run premium only.
Back when premium went over $2.50 a gallon ( boy, I wish for those days again) I started running regular unleaded. I noticed it was harder to start, I had to advance the throttle and choke more to get a cold start, and I lost 4 mph on the top end.

My old Ranger has 2-20 gallon tanks, I ran one dry and put premium in that one.

Problems went away. That's how I figured out why to run premium. Mid-grade did not cure problem. It was just as bad as regular unleaded for me.

The Chevron claim- I don't know about that. I do know that every additive that a fuel manufacturer puts in mean less BTU's from gasoline available. The additives allow the manufacturers to use lower grades of crude oil, and do less damage to our motors, fuel lines, plastic gas tanks, ...

Gasoline is pretty corrosive stuff on its own.


2 stroke outboard motors are pretty high-tech, they aren't like car motors that lumber around at close to idle speeds even when cruising down the freeway at 75mph. Our outboards aperate at the top 1/2 of the rpm range most of the time, an still have to start well and idle smoothly.

[CORAL 96]

Chevron is good stuff for outboards. I try to run it in mine as often as possible (mid-grade), but sometimes you have to run others when it's not available (Marinas). The Techron in Chevron gas is a good cleaning agent and prevents carbon build-up which is a killer for outboards. I think it may even last a little longer in your tank untouched before it eventually breaks down like say if your boat sits for any length of time compared to cheapie brands. When it's not available to me, I try to put a can of Seafoam in it to keep things clean & stabilized!!!

[Fast 492]

My first boat was and 1986 with the blackmax 150 and I blew it up by using premium gas (chevron). The older motors were not designed with the additives in mind from the newer premium fuels. I put a new powere head on it and ran Mid-Grade and never had another problem. I now have a 1996 492vs with a 225 EFI that has a ton of compression ( milled heads ). If I use any other fuel besides Chevron premium, the motor runs about 5-10 degrees warmer. I will continue to use Chevron Premium until this motor goes bye-bye. Good luck...

[rickd]

To sum it up then would be to run mid grade and put in SeaFoam in it every other fill up? I used SeaFoam in it just prior to putting a window in the power head. I was told by a friend to use SeaFoam, he talks about that stuff like it was a religion. I’ll talk to Mike up at BoatMasters when I pick it up, can’t wait to get back on the water!

[Ken C.]

I think the deal with Chevron is that their cleaning agent - Techron - is rumored to be virtually the same stuff as Qwikleen and RingFree. Who knows? Rick, you said you launched your old motor when you put in some Seafoam. Had you ever used any additives like that before or was that the first time?

The de-carbonizing agents such as Qwikleen/Ringfree/Techron help prevent carbon build-up on the surface of the piston, the inside of the combustion chamber on the head and particularly behind the rings on two-strokes. I can't say for sure that if you run strictly Chevron with Techron that you wouldn't need to add any of the others - ask your mechanic since he is the one who hopefully rebuilt it and will hopefully be giving you some kind of warranty with it!

[rickd]

The reason the motor went was because the oil lines weren't original Merc lines. The motor was starved for oil and threw a rod through the side.

I should have serviced it after purchasing the boat, expensive lesson.

[Ken C.]

Oh, that's right you just bought that boat recently... That bites! Well if it's any consolation the oil line deal is the kind of thing that may have been easily overlooked during an inspection/service...

BTW - the offer is still there if you want to come over and check out the front deck on Jason's boat! Let me know.

[CORAL 96]

Seafoam is great stuff all around. One, you can de-carb your motor yourself in a "shock treatment" formula, 2. cleans inside of your motor just by running if you aren't using the greatest fuel, 3. stabilizes your fuel for storage or infrequent running. Great protection all in all. Some of us don't have the luxury of running every weekend (me included)!!!

[Jerry Tilton]

be sure and check for alcohol in the premium fuels. i am pretty sure that is how they raise the octane. alcohol draws water to it and that will ruin your engine.

[Jeff Jewell]

we have gone over this subject many times in the past, If you use the search function you might find more info on this.
Here is some facts though, In Nor Cal there are 5 refineries, Chevron in Richmond, Phillips-Conoco in Rodeo, Shell and Tesoro in Martinez and Valero in Benicia. They all use the Kinder- Morgan pipeline, They all make the same California Carb Blend gasoline, the additives if any, are added at the terminal. The EPA has an oxegenate mandate that requires ethanol be added to Carb gasoline, remember MTBE has been banned. Ethanol attracts water, so more important than the brand of gasoline is to be sure and use a busy station with alot of turnover.

[Ken C.]

Ethanol attracts water, so more important than the brand of gasoline is to be sure and use a busy station with alot of turnover.

And install a water-separator filter (Racor, Yamaha, etc.) on your fuel line!!!