Who is buying premium gasoline?

Bait O' Eggs · 04-20-2001, 09:28 PM

When I bought my boat the dealer told me to always run premium fuel thru it. (115 hp yamaha pump) I did for a few years but..... when the price of gas took a jump I started running regular unleaded and it doesnt seem to mind.

Is it worth the extra money? I cannot tell the diference.

I do spring for the yamalube though.

Sockeye · 04-21-2001, 02:57 AM

Bait O Eggs; Last time I took my boat to the shop they told me I should be using premium fuel also. Considering the price of gas compared to a rebuild or a new engine I'll take the premium. The shop should know. I don't think they have any ties to the gas companys for kickbacks so they have nothing to gain by saying that. I own a 90hp merc and they also told me to use Johnson outboard oil cause it burns cleaner and to also use the fuel stableizer if its going to sit awhile.

Hottamale1 · 04-21-2001, 04:22 AM

Bait'o...

This is strange. You've seen my new Yamaha 90 Pump. It's 2 months old. I was told directly from John Kunzman, owner of South River Marine to NEVER use Premium Unleaded in that motor...only Regular unleaded. It had something to do with the increased additives in "Super" that these motors did NOT like in the long run. He did however give me a small bottle of Yamaha "Octane Booster" which apparently is better than using Premium. It's not called "Octane Booster" but that's what it is. Costs about $6.00 / Bottle...Apparently you use it VERY sparingly.

I would suggest calling SRM and asking Terry, the Mechanic what HE suggests or Dave Tronn, the manager. They're located on McLoughlin in Milwaukie...you knew that.

Scott www.hottamaleoutdoorshow.com

Kinebra · 04-21-2001, 05:54 AM

I was told the same thing as Scott.
"something to do with the increased additives in "Super" that these motors did NOT like in the long run"

It may have something to do with buying my boat from the same shop, but that was 3 years ago and they where singing the same song (and it wasn't the "Springer Singer")

Pitch Pocket · 04-21-2001, 07:06 AM

I've used premium in the past, but noticed that when at a marina (anywhere) the only fuel available is regular anyway. The boat with a 150 Merc pump has run fine with it. Has anyone ever seen premium at a boat dock or marina.

Rippenlips · 04-21-2001, 08:07 AM

BOE, you need to find out what the engine was designed for. Everybody has an opinion. engines are designed to run with a certain octane rating. I can almost guarantee that it states it in your owners manual. The difference is the temp. the combustion chamber will run at. Regular runs hotter than premium. Regular generates more BTU's but burns alot faster which can cause detonation in high compression engines. 2 Strokes are very sensitive to detonation, (holes in pistons) I would do what the manual recommends. Hope this helps.
Jon [img]images/icons/grin.gif[/img]
Did yo get a anchor system?

dawhunt · 04-21-2001, 02:31 PM

I have a 140 horse Suzki and duckworth told me when I bought it 10 years ago to run nothing but the best fuel.Premium !!
Bob [img]images/icons/confused.gif[/img]

[ 04-21-2001: Message edited by: dawhunt ]

DanS · 04-21-2001, 03:33 PM

Link to interesting info on gasoline and octane ratings:
http://crystal.biol.csufresno.edu:8080/projects/9.html

Doubletake · 04-21-2001, 06:27 PM

My company did some research into the different octane ratings for gas and the studies looked at stated the higher octane is for if your motor knocks using the lower octane.(for autos) Mercury recommends 87 or higher for the 175 Sportjet I have, it has been running great on regular unleaded.

Good luck

Doubletake

WaterDog · 04-21-2001, 07:08 PM

A 40hp merc I had ran on premium and after a tune up it was stamped on the invoice "Engine tuned for premium gas, Use premium fuel only". My last motor, a 90hp johnson ran on regular with no problems.

My kicker however was worked on 9 months ago and the mech said to use premium gas cuz it was "tuned" for it also.

KarenLee · 04-22-2001, 08:24 AM

When got my alumuweld the dealer said run premium. I ran regular cause i'm cheap. M ytwo stroke 115 hp Merchated it. It would foul out plugs and I could'nt get the damn thing to idle. I switched to premium and now my plugs last 6 to 9 months, (heavy use) and the kicker runs a lot smoother. Evidently Merc tunes the motore to run on premium. (Hey there could be a partnership between the manufacturers and oil companies.) Anyway running premium has solved all my problems. except my teenage daughter. But then I'm running two strokes. From my experiance (what little it's worth)I don't think that four strokes are as sensitive.

Mr. Fisherman · 04-22-2001, 10:17 AM

I ONLY use premium fuel in my boats.

I started this with my first outboard and have never changed.

I figure that I need every advantage possible out on the water and just chalk up the extra expense to the overall investment.

Just my .02...

HORNBLOWER · 04-22-2001, 01:18 PM

Several years ago some boat owners, frustrated with the "lasting-quality" of the fuel they were getting began to promote the use of 100 octane aircraft fuel. I decided to contact the manufacturer's rep. in the U.S. (I have a 115 h.p. & a 15 h.p. kicker--both Yamaha's) Several phone calls and a week or more later, I got an answer from the tech. staff in California. They were emphatic--- DO NOT USE AIRCRAFT FUEL !!!--- Further, they went on to say that use of PREMIUM fuel is unnecessary.... that the engines manufactured in Japan are engineered to run on gas over there, and that it is of lesser quality than in the U.S..... They said to use REGULAR gas that meets the minimum octane outlined in the owner's manual---and the engines will perform just
fine. Additionally,They said to use a gas preservative if the gas is to be stored (not used) for a 3-month period. I have followed this pattern satisfactorally since that time. Has anyone heard anything different, recently, from the manufacturer?