Octane or Tune

[meantrump2]

I experienced an alarming issue with my outboard 6 cyl 150 hp Merc yesterday. It was running fine until I switched tanks. My wife purchased what I think may be 87 octane fuel and I mixed it at 50 to 1 with Penz, synthetic marine mix.

It would idle fine and do part throttle fine but, when I try to go any farther open with throttle it would cut out or blubber really bad like its fallen on its face.
Now it did this to me once before and I ran sea foam through it and the engine ran fine.
My question I guess is what fuel rating should be run in this engine and am I always going to have to run sea foam or an octane boost?
Thank you for reading and any info to help out is greatly appreciated.
Ric

 

[fireguy]

Sea Foam and Octane Boost can not hurt.

 

[happy]

Sea Foam and Octane Boost can not hurt.

Sea Foam Rocks!! Mix it up for a dirty engine (the ratio is on the lable) I ran mine easy thru a tank, and left that mix set in the carbs for a few days, then I went and ran the piss out of it. I use it for my stabalizer as well. No problems with fuel since I started using this stuff a couple of decades ago.

 

[groundloop]

As far as I know your engine needs 87 octane gasoline, anything more will just be a waste of money.

I had an experience with bad gas a while ago and since then have always used fuel treatment and a fuel/water separator with no further problems. I've used the OMC brand treatment in the past and it worked will, but recently tried Stabil marine stabilizer and it seems to be good also.

 

[1979checkmate]

i run premium in my 115 TOP. not necessarily because i need the higher octane, but because it is the only fuel i can get that does not have the darn ethanol in it. Okay the lake gas 87 octane is ethenol free but its quite a bit higher than the premium stuff at the gas station, so i go with premium. My motor does the exact same thing when it has bad gas, in fact there is one gas station i refuse to get gas from for my boat- unforutnately it is the closest one so i have to go out of my way to get decent fuel. My motor sputters like that when its cold quite a bit if i run bad gas or 87 octane, but once its warmed up it takes off. I have just learned to spend another 4.00 a tank and put in the stuff i know will work well. IF i do have to put in 87 or 89 octane, i carry a bottle of sta-bil marine ethanol treatment and add it in. i do have a fuel filter/water separator, but i just like to be safe.

 

[fbpd227]

I know if your "stock" on your mota octane shouldn't be as much of an issue as ethanol is! One quick way to see if your engine MIGHT need more than 87 is to run a compression test. Mine compression as @ 130- 135# So I run 93 octane- probably only need 90 but when I ran the 87 in mine I had "issues"! Since running the high test AND Stabil Marine- NO MORE PROBLEMS ( also have fuel filter/ water seperator- cheap insurance!)

 

[Kary]

We are at 15 motors and counting this year junked by ETHANOL
We have done 86 fuel line replacements due to ETHANOL
3 of the 15 motors had one tank of fuel run through them. Now Suzuki has told us to step up the octane to at least 89. ETHANOL doesn't mix well with most synthetic oils either-becomes gummy and sticky. Fuel quality is a big issue-this year is the worst. Petroleum distributors don't care.

 

[happy]

We are at 15 motors and counting this year junked by ETHANOL
We have done 86 fuel line replacements due to ETHANOL
3 of the 15 motors had one tank of fuel run through them. Now Suzuki has told us to step up the octane to at least 89. ETHANOL doesn't mix well with most synthetic oils either-becomes gummy and sticky. Fuel quality is a big issue-this year is the worst. Petroleum distributors don't care.

It is not the refineries changing the gasoline blends: it is a combination of U.S.A. Government and international interests. Specifically the EPA, as mandated by the Clean Air Act way back in the 70’s, (which has been amended a few times since then) is required to reduce air pollution by certain amounts each year. One of the huge reasons is the result of lead poising from gasoline from the 1920’s well up into the late 80’s in the USA. Please see http://www.radford.edu/~wkovarik/papers/kettering.html for further information. This act came at the same time as the OSH act, better known as OSHA, and was the workings of JFK. If you read the document, you’ll find back in the 20’s we knew about ethanol fuel, and alternatives to lead, so this really isn’t any new news. Not to mention a lot safer for the kids being born today. Here is what the effects of lead has on the body. http://www.manbir-online.com/diseases/lead.htm

I know the causes of ethanol on older boats, some of them probably needed fuel line service and tank cleaning anyhow. I believe this was reccommended in every marine engine manufacture service bullition when Ethanol came out. The gummy bears will go away, as the Ethanol cleans the tank out. Its imperative you do not mix ethanol with older gasoline, as this causes the "gummy bear" syndrom also.

 

[Kary]

Happy, these were brand new rigged boats not used ones
2010 suzukis
2009 ETECs
If you look at ETECS service bulletins, you will see that the pics of the junked out fuel lines were taken at our shop

They mix the ethanol on site, not at the refineries. The mix doesn't get thoroughly mixed. Mostly due to our friendly "foreigners" that own the stations and how much they want to pay for fuel. Fuel is burned faster by cars than boats which sit in the sun. Most of the culprit is sun baking the fuels and so called sea foam additives and changing the chemical composition of the fuels. The concealed tanks are less prone to this problem. We have a process of coating the outside of the tanks in a 2 stage system that also helps prevent this problem.

It is a big problem that we are battling all the time. We recommend that ANY fuel left over 30 days be disposed of. For the same reason mountain sleds and sno pros use covers for their clear tanks if pump gas is used.

 

[happy]

should have read the post a lil better. I'm aware of the phase separation, and well aware of what ethanol does to fuel systems. A few years ago I was changing floats and pumps out of Verado's like they were going out of style. Our shop had it down pat made a lot of money doing those. Fortunately, for the customers, warranty covered it. I retired from the marine mechanic business a few years ago, so I am not up on all the new service bulletins. The cost disposing of fuel today is prohibitive; at least here, it is twice as much as you pay for it, which will get expensive fast. This situation makes it difficult to manage, most owner want to run as hard as they can, and I do not blame them. I run 2 275 Verado's on my fishing boat, and if the fuel has set a while I don’t run the piss out of it, not to mention the Verado will automatically reduce power anyway. I have used Sea Foam in this boats tanks since new, my fuel lines are fine, My Egg Harbor, I ran sea foam in it since 1984, no fuel line problems but I did replace the fuel lines when Ethanol came out.