What fuel should I use?

Guys
I imported a 1988 Bayliner with a 350 chev 4 barrel from the U.S.A. and now have it here in Australia we have the following fuel types, which one should I be using. 91 octane, 95 octane with 10% ethanol or 98 octane these are all (unleaded fuels)

And from information here in Australia they recommend Champion spark plugs RV8C and timing set at 9 Deg B.T.D.C.

Can someone please confirm if this is correct

Re: What fuel should I use?

Ayuh,... It would apear that your 91 octane is already better than our 89 octane, I'd use that...
I Always use AC Delco plugs in Chevys, MR43T is what I'd put in your motor...

Re: What fuel should I use?

Bond-o said:

Ayuh,... It would apear that your 91 octane is already better than our 89 octane, I'd use that...
I Always use AC Delco plugs in Chevys, MR43T is what I'd put in your motor...

Click to expand...

Thank You

What about setting the timing is 9 Deg B.T.D.C. ok?

Re: What fuel should I use?

Stay far away from the 10% alcohol (ethanol) fuels they can cause problems in boats...this is well documuented all over the 'net.
I'd use the 91 and listen carefully to make sure you don't get pinging (detonation). If you do I"d then use the highest grade of no-alcohol fuel you have....after running it a bit I'd also check the sparkplugs to see how they are burning...if you see signs of overheating you need to investigate the cause (lean fuel mixture...over propped...timing too advanced..etc). I run my 88 OMC 4.3 at the specified 6*BTDC and with the 93 octane fuel I use I have never had a ping and the plugs are a nice tan color....but if I was using regular the OMC manual notes the timing should be set at 1*BTDC...
Is this a Volvo, Merc or OMC boat...I ask because it can make a difference...if its an OMC...my manual lists the following settings:
with 89 octane fuel 8*BTDC
with 86 octane fuel 3* BTDC
if it's an 88 350 it's probably an OMC boat....

Re: What fuel should I use?

In Australia the octane rating is the RON method and the United Sates uses an average of the MON and RON. Your 91 is actaully pretty low. Assuming the MON is 8 points lower than the MON, your 91 is equivalent to 87 octane in the US.

Re: What fuel should I use?

Yes ^^^^ what he said . . . So 91 RON (Aussie) is barely OK. Another one of those flipped up things you have to deal with when comparing things in different countries with different methods of measurement, but maybe even the same words.

In the UK they compare road vehicle efficiency in Miles Per Gallon, but the Imperial Gallon is 20% larger, so mileage should be 20% better. But they flippin' sell fuel in liters and they do maintenance in Kilometers Speed limits are in MPH. Engines are rated in PS, but they say "brake horse". Make me flippin' stop! It's bloody bonkers

Re: What fuel should I use?

G'day Black As.
Check the E10 pump at your local servo and you'll see a sticker saying something along the lines of
"Do NOT use in aircraft.
Check with your manufacturer before using in a boat".
Given that the fuel sellers aren't sure of Ethanol in their fuel, at least here in the Glorious Peoples Socialist Republic of Victoria we have the choice, not like Queensland where the Premier has mandated Ethanol in all fuels. Wonder how big a kickback they got from the motor mechanics??

Re: What fuel should I use?

and if you DO have to run E-10 gas through a 22 year old boat be prepared to change fuel filiters....check fuel lines...check the anti-siphon valve...the problem with ethanol is three fold:
1) it's a good solvent and will clean out the gunk in the tank...which will then clog fuel filters.
2) it attracts moisture which will increase the water content of the fuel
3) when it attracts enough moisture the alcohol+ water will separate out from the gas and the water will wind up in the bottom of the tank...that can cause clogging again of fuel filters....it can also cause the remainder of the gas to be low in octane (the ethanol is also used to boost octane) and you can get pinging and detonation.

I use the 10 micron Sierra filters and check every year the gas that I dump out of them when I put a new one on...make sure your gas cap seal is good and does not allow water in the gas tank...that's the last thing you want with E-10. I had some red gunk in the filter the first year of E-10 and I had to rebuild the carb and replace the antisiphon....but since then no problems....