300x on 87 octane
 

My marina is threatening to stop selling 91 octane this year. I know that the 275 Verado and some of the Mercury Racing I/O's (new HP 850 at least) can be operated on 87. A knock sensor retards the timing or something and the power is reduced. Is this the case with the 300x.

Re: 300x on 87 octane
 

I would assume not, and I wouldn't risk it. Buy some 6 gallon cans and bring gas to the boat. A lot better than melting pistons. I picked up four 6 gallon cans last night at Meijer, they are on sale for $4.84 a piece. By far the cheapest I have ever seen. And it is usually hard to find the 6 gallon cans as well.

Re: 300x on 87 octane
 

I have 2-300x's and 100 gallon capacity. That's a lot of 6 gallon cans. But I may have to do it. Thanks. Anybody else with information regarding the knock sensor.

Re: 300x on 87 octane
 

I would not try it. I am going to run A mix of 91 and AV-Gas (100 octane) in my 300x's just like I did on my 2.5's. Mercury actually reccomended running AV if available, which it is in Havasu. I would think 87 would not run well at all, especially if it is warm where you boat.

Re: 300x on 87 octane
 

You cannot run 87 in a 300x it WILL blow up
There is a fuel addiive on the market called TK-7 made by Tal indudtries, it works...... and is the ONLY additive I know of that does. It is like Crack for motors.
Lastly, Merc does not will not and has not ever recommended AV fuel for it's new ( last 20 years ) hi per motors. Av fuel is for air cooled 1000 foot per min motors, not 3-4000 foot liquied cooled 2-cycles. AV has an additive in the fuel that dissolves oil, this is to prevent plug fowling in an air plane motor. In a 2-cycle it spells death. NO matter how much oil you add it will win, even with double oil your motor will wear out both the rings and bores 50% faster. If you have ever heard that AV runs dry......... that is the reason.

RT

Re: 300x on 87 octane
 

Well I can tell you that Merc HAS reccomended running AV in both the O/B boats I have had. The current has 04 300x's and the other had 2000 280hp 2.5's. Lot's of guys at Havasu are running Av because you can buy it at the pump at several stations and the 100 octane is good insurance for 120 degree temps. Nobody that I know has had any problems.

Re: 300x on 87 octane
 

Well I can TELL you your motors wear out faster, who ever told you to run it needs to take a chemistry lesson or two. Yes it will stop detonation, but you WILL wear it out.

RT

Re: 300x on 87 octane
 

Do you have website or phone number, where do you get this, I have been looking at Max Lead and Octane Supreme 130, but have only heard of people using them in Four strokes(big block Mopars) they are supposed to work good.

Thanks for any info you can give me.
Caleb

Re: 300x on 87 octane
 

http://www.pitstopmarine.com//index....799d43e0b33103

Try that.

RT

Re: 300x on 87 octane
 

OK I did the math. That stuff requires 1 ounce to the gallon of 87. That means 1 gallon does 130 gallons of gas. At $115 plus tax plus shipping for a gallon of the stuff, it works about a buck a gallon above the price of 87. Those $5 red cans are looking good. Any body know a good way to transfer gas from them instead of holding them by hand. Thanks for info.

Re: 300x on 87 octane
 

Can you send a link to more info on this stuff?

Re: 300x on 87 octane
 

I am also running 300x's and have a concern that 91+ is going to be hard to find in one of the area's I boat. Im under the belief that 89 is out of the question.
Is this TK-7 stuff safe to keep on board or is it highly flammable. I would be interested in keeping a few gallons on board to add if the fuel I was putting in was questionable.
Thoughts?????

Re: 300x on 87 octane
 

Are there any other octane boosters that work?

Re: 300x on 87 octane
 

get a gas caddy.... 30 gallons with a a hand pump..... check out overtons... :cool:

Re: 300x on 87 octane
 

Where did you see 1 oz./ gallon, on the link Firewalker gave it says 1 oz/6 gallons. that means a gallon will treat 768 gallons of fuel which is only $0.15/ gallon of treated fuel, if the stuff really works it would be cheaper than buying 92 all the time. I just don't know if I trust the stuff????

The maxlead 2000 at $30/gallon comes out to $108 for the same amount of treated fuel their website is http://www.maxlead2000.com/

There is also Octane supreme 130, their website is
http://www.kemcooil.com/product_info.php?pId=61

A friend has used Maxlead 2000 in his 440 that needs 104 octane to not run on at shutdown and it worked in it, that's the only experience I've had with it.

Re: 300x on 87 octane
 

I looked at the Gas caddie but at over 300.00 in the past it wasn't cost effective ...fuel dock 10 mins from my dock is @ 2.42 for 92 octane and 20 mins away I can get 93 for the same price or usually less ....92 at the pump is running almost the same if not more ....plus your looking at over 200lbs for a full caddie ....

Re: 300x on 87 octane
 

I have 200 gallon tanks, got four - 6gallon cans thats 24 gallons. I fill up before I go to the boat dump fuel in. Drive 1/2 mile to the gas station and fill up another 24 gallons. I never run far enough to burn 200 gallons, so I usually only put 48 gallons in at a time depending on weekend usage and how low I run the tanks. It is not bad, especially if it will save your motors. ALso I took off the oil injection for reliability, so I dump a 1/2 gallon of oil between the 4 cans and pump 24 gallons, for a 48:1 mixture. The gas is cheaper on land too, obviously. It may be a little extra labor but it will save your motors and your $$$$. Buy more cans if you dont have a close station. $5 a can is cheap!!

Re: 300x on 87 octane
 

Just got off the phone with the Merc guy and he still reccomended AV in the Havasu heat. He said that losing a motor due to low octane was more of a concern than AV being "dry". He also said to mix 50/50 of 91 and AV unless the motors will be run hard and in that case run straight AV. Everybody has different opinions but I will stick with what Merc says.

Any updates on 300x and fuels recently?

Never thought I'd say "those were the days" about $2.42/gal but those were the days. Just goes to show what a porking the American public is getting now.

300X + 87 octane = BANG, BOOM, SEE YA!

The 300XS also requires 91. Using 87 may result in a smaller BANG, BOOM, SEE YA.

You can do you own blend.

1 gal 87 + 1 gal 93 = 2 gal 90
1 gal 89 + 1 gal 93 = 2 gal 91

You can also use a good octane booster. Remember octane rating is not a measure of the energy/power in the fuel, it is just how compressible it is.

I should note, that some vendors will put a different mix of additives in various octane rating gasolines, and some additives can promote better/longer engine life.

Octane is the resistance to burn not compression, never seen an octane test that compresses the fuel. Preignition or detonation is the fuel lighting off too early higher compression and temperatures require a higher resistance to ignition to slow down the burn rate