Oooooops

I noticed the other day on the inside of the cover on my 1955 7.5 Fleet Twin it calls for 1 pt. Mobile SEA 30 oil to 1 gal. 87 oct. gas. I’ve beed running 50:1 TCW-3 oil. Have I done any harm? It still starts and runs. I’m going to dump the tank and mix with 30 weight, but is there anything special about Mobile 30 weight as aposed to any other 30 weight say Castrol?

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Thanks Middleground will do. Hay does your name refer to the middlegrounds of the Chesapeake bay by chance? Good fishing there boy.

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Outrage 19,<br /><br />Please email me at seahorse5@hotmail.com as I have a question about your Whaler.<br /><br />About 30 grade oil, don't forget that the service manuals back then also recommended annual carbon cleaning from the tops of the pistons and the exhaust ports. Today's outboard oils are greatly improved over the car oils of 50 years ago, but mix the fuel at 24:1, or 16:1 if you want more smoke.<br /><br />The 7.5 was prone to throw rods if it was over-revved, so do not operate the motor at full speed if the prop is worn down from running in sand.

Re: Oooooops

Originally posted by Outrage 19:<br /> I noticed the other day on the inside of the cover on my 1955 7.5 Fleet Twin it calls for 1 pt. Mobile SEA 30 oil to 1 gal. 87 oct. gas.

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One pint to one gallon????<br />Sure seems like 8:1 to me. Would the motor even start and run on that mixture?

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Stick with the TCW-3, it's much better than the old SAE 30 recommendation.<br />I've noticed some of the oil ratios they recommended on the tanks back then were wrong, and often conflict with what they recommended in the owners manual. <br />For example my Johnson tank states "One Quart to a tankful (6 Gallons)" which is 24:1, then in the very next sentence says "Or half a Pint to one Gallon" which would be 16:1, sounds like someone wasn't paying attention in maths lessons! <br />As Charles says 1 Pint to 1 Gallon is 8:1 which is far too much, even my old Seagull only takes 10:1 and that's a LOT of oil!<br />24:1 should be more than adequate with todays oil. 50:1 is not enough, but with luck you won't have done any damage and if you switch now all will be fine.

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Thanks Charles and petrolhead. I was going to take Middleground's advise and usw TCW-3 oil at 24:1. Your input reinforces that decision. I've had it for two years now and have only put about 10 hours on it. I was cleaning it up to sell and noticed the sticker on the inside of the cover.

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petrolhead,<br />My Milemaster 4 gal. tank says what you quote, but it's quite correct for a 4 gal. tank.

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Hay folks I have to correct myself here. The inside cover says 1/2 pint Mobile SEA 30 oil to 1 gal 87 oct.

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I'm pretty sure it said "87 oct." but then I also thought it said 1 pt. to the gal.

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Your right Middleground it says 1/2 pint Mobile SEA 30 to 1 gallan of regular gas.