Fuel

[Sean]

Just curious, what grade octane are you guys running with?

[macojoe]

I run 87, its not always best to use top grade gas!!

Go by what the manufacture says to use, using a top grade in a motor meant to be used with a lower octane may even hurt the motor sometimes!

[C YENSEN]

I USE WHATEVER THEY GOT AT THE DOCK, NOT SURE WHAT OCTANE

[shicks007]

87 Octane

[chumbucket]

Unless the manufacturer recommends something higher, just use 87 octane. Anything more, and you're just throwing money away. If you have the money to throw away, send some my way and I'll put it to better use than higher octane costs. ;)

[captbent]

87

[sfprovyn]

I use 87 or 89 and throw in a can of seafoam every third tank full...Frank

[Mac_Attack]

87 with Sea foam Billy Mac ;D

[Sean]

Alright, I am going to change my screen name to, 1 million and 1 questions".
Why the sea foam?
Thanks again...

[rb437]

I use 87 also. Higher octane fuel is less volitile and therefore of no benefit unless you have an engine that requires it to run properly. Bottom line is high octane fuel in an engine that doesn't need it is bad for your wallet. Low octane fuel in an engine that should have premium is bad for your engine. Buy only as much octane as you need.

[Mac_Attack]

Seafoam helps to decarbonize your motor. Cleans carbs and helps to free sticky rings. It can also be used to stabilize your fuel. Billy Mac ;D

[Sean]

BillyMac, nice 1000 posts... Thanks for the info all. If you are ever in the newport area i owe a few of you a few beers ;D

[chumbucket]

I could be tempted to make a drive to Newport..................... ;D

[Skools Out]

saw on discovery that if you buy 87 and test it in a tank 1 month later the octane will be around 86 to 87 still but if you buy 93 and let it sit a month that the octane reading was 84 to 85 so they said if you don't plan on using up all the fuel right away then just buy 87 due to less additives that will go away after time when stored in small amounts like less than 1000 gallons. i thought that was neat to know that it was better to buy 87.

[sfprovyn]

87 is probably the way to go but most marinas have 89 which has probably been sitting around with lots of water in it and turned to crap so thats why I throw in a can of seafoam now and then just in case. A friend of mine works on everything and told me that 8 out of 10 of the motors that he works on have crappy gas or water in the carb from condensation so he recommends running everything dry or pickle it with seafoam or stabil but he thinks seafoam is better..Who knows..I've had motors I've ran hard with little maintenance for years and others that I did everything by the book and they still blew up...One thing for sure the gas on the market now is bad and is getting worse as far as outboards are concerned ... Frank

[turbinedoctor]

I dont have the manufactures manual for mine but I have had two different mechanics (one a merc dealer) tell me that my high compressoin engine needs the high octane, "You may get away with it once or twice but she wont last long will the low octane".

As the other guys said "read the manual and do as it says. If its under warrenty you dont want to get caught out side of what they reccomend.

[Skools Out]

low octane won't hurt the motor. My corvette calls for super only but 87 doesn't hurt it, actually lower octane runs cooler, high octane burns hotter which i would say cause's more engine heat and a shorter life. What yr motor is this and what is the compression they say to run it in anyway?

[turbinedoctor]

Its an 84' 90 hp merc with 110 psi on each cylinder

[Skools Out]

LOL oh no they told you a fish story on that one you will be fine with 87 lol or less. i have several 140 hp Johnson's and the book says run 87 to 89 octane and they have 136 to 150 per cylinder depending on which motor it is. but 132 to 136 is factory onthose and they say run 87 to 89.

[Skools Out]

hey actually my 2 stand up racing jet skis motors have 195 psi even on one motor and i run 87 no problems and the other has 210 psi even and i run 87 in it no issues.

[macojoe]

84 , 90hp Merc

I had a 90 and a friend had a 89, both run on 87!! The friend i seak of bought it brand new, still owns it and it runs fine always on 87!

Some one sure telling you a tale!