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HOMan.
Was wondering if anyone else has read there November issue of Bassmaster magazine, more precisely page 14 “Not so corny fuel problems”. I found it interesting that the writer said buying premium fuel(i.e. 93 octane) will not add to the performace of the engine. According to him engines are engineered to run best on 87 octane. I vary seldom comment on this board but i found the article very interesting reading, he also goes on to brag up “stabil” fuel stabilizer. Just was wondering everybody opinion on the octane comment. He also goes on to say the 92 and prior motor owners should pay especially close attention to the rubber on the fuel lines, fittings etc. on there respective engine. I run a 93 merc on a PII and was wondering if that year and up was more compatible(if thats what you want to call it) to ethanol? Would like BCBs opinion on this also. Especially the octane comment. Sorry so long i just thought it was interesting article.
I have not read the article yet. Though sounds like the guy was pretty informative. The octane issue is dead on and you should only be running what the manufactuer recommends for your engine. Most of todays engines are designed to run on regular 87 octane. Though some of the higher HP models will need 89 or 92 octane again these engine were designed for that use of octane. It has to do with the combustion rate and temp of ignition that can lead to premature engine failure. Unlike like many who believe they will get better ignition or more HP with a higher octane are making a big mistake and are more then likely going to cause premature engine failure. Run what the engine was designed to run on, and for most applications this will be 87 octane. As for the stabilizers, ethanol is no joke, it will eat away your fuel lines from the inside out, basically clogging everything in the fuel system. I would highly recommend getting the new etahnol resistant fuel lines installed from your dealer, i believe these came out sometime in 2008 and will say ethanol resistant on the line. And use an additive, whether its seafoam or marine stabil… just use something. I would also avoid filling the boat up after every trip unless you know it is going to be used within a relative short period of time. Ethanol begins to break down in a short amount of time and can have full separation of the fuel within as little as 28 days. Ethanol is bad stuff especially for use in bassboat applications where we tend to let boats sit from time to time. Most in the auto industry do not here about the problems because we drive our cars/trucks everday and therfore fill up more ofetn so the fuel never gets the chance to breakdown. Also one last thing dont limit this to just your boat, remember to treat the gas in all your outdoor power equipment such as lawnmower, edgers, chainsaws,dirtbikes… etc;
Luke, Like the other posters, I agree 100% that you do NOT want to run premium fuel in current model outboards. The manul on Mercury specifically identifies 87 octane as the fuel of choice. You will not gain performance from higher octane, and you could well damage the engine. You need to buy gas in quantities that you will burn quickly, and not store the boat with lots of fuel. And yes, you do need to plan on running a fuel treatment like Marine Stabil in your gas. I buy it by the case, and religiously add it to the fuel. Mike Whitten/Germantown, TN
in complete agreement with the replies above. higher octane does not = higher horse power. higher octane fuel has a slower burn than lower octane fuel and therefore may leave carbon deposits behind on pistons and rings. these deposits can lead to engine failure. todays engines are designed to run on the the manufacturers suggested octane rating. do not try to overdo what the manufacturer has tested hundreds and hundreds of hours over. Fuel additives such as Stabil, Mercury Quikleen are designed to aid against carbon deposits. Gasoline today has also the tendency to attract moisture from the air and those additives will help against that as well. Your 93 Mercury is less compatible to ethanol, but more compatible to run the higher octane fuel. Though you should check to see what is the recommended fuel to burn in your engine. You need to keep an eye on all things (hoses) that are either rubber or plastic as ethanol will do a number on it. better yet, try and purchase fuel that does not have ethanol in it.
Wow Dude write it on the calendar……Ive been told that Mercury Quikleen, BRP 2+4 Fuel Conditioner, Stabil “Marine” and Sea-Foam are all Great Products….Im sure their are others out there, another for MOST of you to use is the De-Carb products made by Evinrude, Seaworthy ETC, alot of guys runnin petroleum based oils need to de-carb their motors, or we know what CAN happen, not always, but its a $8 product…..I use Shell 93, mainly because of the quality of fuel and no ethanol in it, you guys are right, unless your running a XS Racing motor or a Older Carbed OMC or any 2 stroke the 91-93 octane actually can hurt…..I tell my customers to simply use the best gas they can, I tell them about the octane stuff but for some reason my Psycho Detailed guys said theyve Never lost performance from running the Shell 93 in their HOs, and my Opti guys same thing……But most folks spend $20,000-$60,000 on a boat and then cheapen up when it comes to a couple extra bucks at their $75 fuel fill up……Cheers Dudes…..and yes Im the HO Guy….Your Signature …
I use marine stabile and have ever since i bought the boat, IMHO it is a great product, and usually use a mid grade fuel when filling up if possible. I just thought it was some interesting reading. It seems like the issues are going to continue with this whole ethanol thing.
I found the article interesting with regard to the octane issue. I was not aware that running a higher octane could be harmful. I usually use Exxon because they do not add ethanol so it is pure gas. It costs a few more cents but even for cars it is better because pure gas results in better gas mileage. I will check the specs and use only that octane in the future.
Does ethanol affect horsepower or fuel-efficiency? Ethanol has a heating value of 76,000 BTU per gallon, which is approximately 30 percent less than gasolines heating value (which is approximately 109,000 to 119,000 BTU/gal). The result is E-10 gasoline which should yield slightly lower mileage – a decrease of approximately 3 percent. Fuels containing higher levels of ethanol will have a corresponding reduction in mileage. For example, E85 fuels produce mileage approximately 30 percent less than gasoline. The octane rating of pure ethanol (200 proof) is about 100 and is therefore useful in elevating the octane value of gasoline. In E-10 blends the presence of ethanol provides about 2.5 to 3 percent of the overall octane rating. The effect on engine horsepower is determined by the octane result of the blended fuel. Care should be taken to select fuels having the octane rating recommended for the engine as indicated in the owners manual for proper operation. Saw this on Mecury site so now I wonder if the blended fuel octane is the same as the octane recommendation in the manual? Bueller? Any one? Any one?
Should I add an additional fine-micron filter to the system to prevent debris from entering the engine? The addition of another filter to the system will create another possible flow restriction that can starve the engine of fuel. Mercury already provides the appropriate level of filtration to protect the engine from debris. Mecury does not recommend the fuel filter that the author suggests as added protection
Billfish we are from now on adding the Water Separating filter like Yamaha does on all factory rigged boats…..Is that what you meant for a Aux filter? IF so their are 100s of places to hide it and it really can save your Azz….Brannon H.O. Promoter
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