What Type of gas to use in my old boat?

[Taynton]

I have a 92 ski brendella, it has the pcm 351 (carb) and on the motor it recommends 87 leaded fuel (lol).

I know a bit about fuels and how they interact with engines, my question is what fuel would be most ideal to run?

 

The 91 octane is usually what I run because it has no ethanol, however apart from the non ethanol part I feel like its a waste in this old motor set up for 87 leaded. I do like to skydive so I can always get av gas pretty easy as well. I was thinking about adjusting the timing for the 91 but not sure this is the right path.

 

I ski on okanagan lake 1000' elevation and I do a lot of cold weather skiing

 

Cant wait to see your responses!

 

[ReallyGottaSki]

I know its hyperbole, but you could probably run camp gas in that engine.

cr is in the low eights.

If you keep the boat dry, and empty the bowls at layup, its your call whether ethanol free is worth it, my experience says no if you are using it for sessions at least weekly.

 

If you want t go faster quicker do heads cam intake; timing alone will not get you much at all unless it is already far off.

[BraceMaker]

I run ethanol through my boat during the summer but before lay up I treat that fuel, then run the tank near empty then try to run atleast 2 or 3 cans of rec gas through it before it goes away.

 

About 2 times a summer I dump the fuel water separator into a mason jar and let it settle out to see if I'm getting any water in my fuel - rarely do I find any.

[MDB1056]

My 92 GM 5.7 Magnum runs better on 93 Premium. Running 87 I often get run on at shut off. It's never an issue with 93. I don't even think about it anymore. That's just what it likes. 93 all day. @Taynton - great boat! A ski buddy has the exact twin. Gorgeous. He's coming out today to ski. I'll ask him what he feeds his and why.

[6balls]

cool boat. I know that doesn't answer your question.

[BraceMaker]

@MDB1056 That's usually called "dieseling" in a carbureted engine i'd also check to see if your hot idle is high.

[DW]

I would consider ensuring your fuel lines are current, thus ensuring compatibility with today's fuels. The needle and seat in the carb may also need an upgrade. Avgas has a lot of additives that are of no value for boating use and actually a lower BTU value hence a decrease in performance. Your carb is calibrated to automotive fuel, not Avgas. With that, I would then go with the 87 fuel.

Great looking boat, my ski buddy opines fondly of his old Brendella.

[Horton]

petroleum

[TomH]

I've been looking through a few PCM manuals of that relative era over the past few days, and what I read was minimum 89 unleaded is recommended, but 87 is ok if you retard the timing 4 degrees (for a carb boat).

[Zman]

My ski partner runs his 89 Ski Brendella on nothing but regular gas. Runs great.

Definitely install a new fuel line that is compatible with today's gasoline, soon. We replaced his a couple years ago, and the inside was collapsing, and one section was so brittle that when I bent it slightly, it broke in two.

As others have noted, never let today's fuel lay dormant and untreated for long periods in your tank or carb. Heck, even gas before ethanol was added could not remain dormant in a carb over a long winter. Back in the 80's I rebuilt many carbs that had simply become plugged up with 'varnish' left behind as the gas evaporated from the carb. Usually, a simple disassemble, clean out the varnish, replace soft parts, and reassemble.

Always run your carb dry before layup.

Very sharp looking boat you have!

[BraceMaker]

Fuel lines are something you should just buy a spool of eaxh size and keep around the lake. Too many wasted days of my life when some old fuel line on one boat or another degraded and started plugging floats. That and buy an oetiker ear plier set and a load of clamps. I do not use screw clamps on fuel lines. Cut the old one off pop a new one on. Lines take seconds and don't leak.

[ETskier]

I buy Lucas fuel treatment by the gallon. A couple oz per 5 gallons helps minimize any effects of ethanol. Also good for winter lay up.

[Taynton]

wow! thanks for the comments, The PO had all the water lines and hoses replaced so Im assuming the fuel line was done also but Ill check that, I ski every day the lake is calm so no worry about gas sitting around lol looks like Ill be able to save a few bucks this summer on the premium thanks for the input and compliments guys! I really love the brendella and restoring it has been rewarding for sure! This forum has been a great help! thanks again!

[GaryJanzig]

I have the same engine. The engine manual says 89 octane or higher. I use 90-91 octane ethanol free. If I can't get ethanol free, I buy marine Sta-Bil, and have had no problems. If you can't get ethanol free make sure you keep your engine compartment as dry as possible.

[fu_man]

If you would have asked me if leaded fuel was still available in 92 I would have said no way. I thought it went out in the 80s. Huh.

[vtmecheng]

I thought leaded engines stopped production around 1979, even in boats. They figured out how to make valve seats that were strong enough to not need the leaded gas and it was mostly implemented by then, even in inboards and I/Os.

[swc5150]

I only put non ethanol fuel in my ‘94, and it just so happens to only come in 91 octane near my house. The octane may be overkill, but ethanol is no bueno for the old girls system.

[skiinxs]

Non alcohol is always good if you can get it. (I can't). If you don't hear it pinging on 87, it is probably fine, if it pings, bump up the octane or retard the timing, it will not adjust itself. I can't stress enough the safety factor on what everyone else has already said about fuel hoses. The original hoses on your boat were not alcohol resistant. Even the newer ones designed for alcohol in the gas eventually succumb. I have seen old hoses swelled up as big as my fist and leaking. A few drops of gas turning to vapor is a highly explosive bomb!

[MDB1056]

@Taynton - ski buddy with your same boat runs regular 87unleaded, always has, no issues he says.