TRUE? I have to burn ethanol, retard timing?

[audiobill5]

Great forum!
Opinion poll time:
An outboard service yard told me on my 1972 50 hp Johna/Rude fishin' mota, that runs on E10 (all we can get in Massachusetts) that I should not run at the stock timing setting of 19 degrees @ 5500 RPM: I should time to a setting at least 2 degrees less to have the engine hold together longer.

Is this fact or fiction?

Would the change in timing even make a difference the way it performs?

Thanks,
Bill

[sabine river killer]

you need to use ethanol approved gas hoses and check the jetting and retarding the timing will cause you to loose some bottom end power but i do not know if you need to do that or not the ethanol is very new to me and am old school

[Aeroliner]

Over this past year we have been using up to 10% ethonal in our racing fuel with the NBRA. So far there have been zero issues with our engines or the fuel for that matter. We normally time our 4 cylinder mercs at .365 and have not changed that for this new fuel requirement. We do run a slight bit richer with the blended fuel. The additional of ethanol actully increases the octain a slight amount.

Alan

[Mark75H]

The additional of ethanol actully increases the octain a slight amount.

Which allows them to reduce the quality of the base gasoline stock. 87 at the pump is 87 regardless of whether it has ethanol or not, same for 89 and 92/93.

If the ethanol was being added to finished 87, then it would increase the octane ... but the gas companies know they only have to meet spec on the finished product ... some states let them get away with below grade sales - other states actually test samples and fine stations selling below grade.

I would not change the timing on a motor like a '72 50 hp twin.

[microbream]

definitly check fuels hoses to see if they are compatable to ethanol.
You should not have to retard timing, however expect less bang for you buck, ethanol has a much lower energy rating than gasoline. I won't use the stuff anymore, for the cost saving it is just not worth the fuel economy reduction IMO.
Here in oz we have the choice of 4 fuels. E10 (10% ethanol 90 octane), unleaded (90 octane), Premuim unleaded (95 octane), and super preamium (98 octane).
I ran E10 on my new model merc (service manual said it was ok).
Now i run 95 on my suzuki but is has 190 psi compression.

[fs5]

ehtinol loves eating out your primer bulbs and clogging your needle and seet in your carbies with the disoved rubber.
been there a couple of times with my merc.
as long as all your fuel lines / fittings can can handle it ,i don't reckon it hurts.don't let it sit in your tank for too long either ,it can sludge up in a month or two.keep it fresh .
it won't be long and we'l all have to run it ,even over here....

[audiobill5]

So can I run bigger than #58 jets and advance it a couple degrees if I run e10 fuel but 92 octane?
Thanks

[Bill Gohr]

Well in you've been running alcohol laced fuel since the mid 80's, the amount of it was based on the state laws so.......

The other scenario is remember the easiest way to increase octane is to add alcohol so alot of some fuel's high octane fuel may have more alcohol than others.

So, the best thing to do is buy name brand fuel and go with the mid grade is commonly is the best quality fuel and has the chance to have the least amount of alcohol.

As well, lowering th etiming 2 degrees is not a bad idea, and you probably will not feel a loss of performance but the motor will know the difference.

In the 80's we had a chart that listed what motors needed to be detuned for alcohol laced fuels, some got thicker head gaskets, some got reduced timing but I don't think we said to do anything to your engine.

[Aeroliner]

Well lets go back in history. Mercury produced the 75-H with a flywheel marked for gas and alky. If I remember correctly the gas mark was 40 degrees before TDC and the alky mark was set at 44 degrees. With the small amount that is currenly added to gas I would keep the timing at factory spec. As Sam stated you really don't know how the fuel is blended but if the octain is what the OEM recomends then I would not change it.

Alan

[quick2008]

Having a read here..and Just a general quesiton,
Im assuming that Methanol has a lower BTU rating than regular gasoline?