Fuel Requirements

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   Hey Guys,

So I was thumbing through the PCM Owner's Manual the other night and came across the section on fuel requirements. I was surprised to see the section that said 93 Octane Leaded Fuel is recommended and not to use unleaded fuel...

Is this really required? I thought that you couldn't even buy leaded fuel anymore other than av gas?

Should I be putting an additive into the fuel for my 302 and is 93 Octane really required?

Thanks 

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skitique179 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: December-06-2011 Status: Offline Points: 176	Post Options Post Reply Quote skitique179 Report Post Thanks(0) Quote Reply Topic: Fuel Requirements Posted: March-15-2012 at 11:50pm
	Hey Guys, So I was thumbing through the PCM Owner's Manual the other night and came across the section on fuel requirements. I was surprised to see the section that said 93 Octane Leaded Fuel is recommended and not to use unleaded fuel... Is this really required? I thought that you couldn't even buy leaded fuel anymore other than av gas? Should I be putting an additive into the fuel for my 302 and is 93 Octane really required? Thanks

SNobsessed Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: October-21-2007 Location: IA Status: Offline Points: 7102	Post Options Post Reply Quote SNobsessed Report Post Thanks(0) Quote Reply Posted: March-15-2012 at 11:56pm
	No additives! Waste of money. I use '87 octane non ethanol ( we still have that in Iowa, where gasahol was born, go figure). If it doesn't knock, you are good to go skiing.
	“Beer is proof that God loves us and wants us to be happy.” Ben Franklin

Keeganino Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Grand Poobah Joined: October-27-2009 Location: North Carolina Status: Offline Points: 2063	Post Options Post Reply Quote Keeganino Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 12:24am
	I always use 93 in my 1973 Skier (Waukesha 302)which also calls for "High Octane Leaded Gasoline" Have never tried using lower octane and probably will not ever, but my engine is stock and has never been rebuilt. Modern gasoline already has components in it that take the place of the lead so there is no need to waste money on the additives as stated above.
	"working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger 1973 Skier

8122pbrainard Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040	Post Options Post Reply Quote 8122pbrainard Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 8:36am
	As mentioned, no additive needed. I've been running 87 in my 302 since I got it without any problems.
	54 Atom 77 Tique 64 X55 Dunphy Keep it original, Pete <

Jllogan Members Profile Send Private Message Find Members Posts Add to Buddy List Platinum Member Joined: May-18-2011 Location: canton, OH Status: Offline Points: 1728	Post Options Post Reply Quote Jllogan Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 11:18am
	I switched over to 89 but the PO always ran straight 87 in it and it ran fine.
	1986 Ski Nautique 2001

TRBenj Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21118	Post Options Post Reply Quote TRBenj Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 11:34am
	Here is the excerpt from the '89 PCM manual. If you are pulling the "93 octane" reference from an older manual, read the fine print. It denotes the method used to define the octane (there are more than one). The verbage called out in the '89 manual is consistent with the current octane posting requirements, as far as I can tell. Do NOT worry about leaded fuel (you cant find any), nor about lead substitutes (theyre a waste of money). Take the savings and put them towards a head job or new heads... it will be a while before you need it. Personally, I run 89 octane, but I would think that with the ultra-conservative compression ratios that these engines run (~8.3:1), 87 should be fine as well. So long as you dont get any pinging (pre-detonation), youre fine.

skutsch Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: June-19-2008 Location: Racine, WI Status: Offline Points: 2874	Post Options Post Reply Quote skutsch Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 2:28pm
	I run 93 Octane but only because it is the only way I can run non-ethanol gas, and then I have to look very hard to find it. When I am in Iowa, I do revert back to 87 or 89, again because it is readily available with no-ethanol. No knocking experienced with any of the fuels above. Oh BTW, the Interceptor 312 (Ford)in the 63 Ski Nautique has also been running unleaded since the early 80's, usually 87 octane in that too. I know its not relavant to a PCM discussion...
	Our 98 Sport Nautique My Dad's 63 Ski N

Bri892001 Members Profile Send Private Message Find Members Posts Add to Buddy List Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4945	Post Options Post Reply Quote Bri892001 Report Post Thanks(0) Quote Reply Posted: March-16-2012 at 2:41pm
	Ski dim has some verbeage about identifying heads and how no raised ribs indicates non hardened seats. It says to run lead substitute or Valvtech. Unfortunately the entire 3 paragraphs blinks I understand that Valvtech is supposed to help for stabilizing fuel, but how would it help the valve seats? Anyway, I feel that adding Startron, Valvtech or Marine Stabil, for the ethanol is good, but I agree not to worry about the lead substitute.

Fuel Requirements

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