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gas/oil ratio

Posted: Sun May 21, 2006 1:25 pm
by Jebby
hey all... i just got a new to me VERY old to every1 else boat... its a 14 foot aluminum and the motor is a 10 hp johnson seahorse from 1954 or 1955..... does any1 know the proper mix ratio.... ive been told everything from 20:1 to 32:1 to 40:1 to 50:1

thx
jebby

Posted: Sun May 21, 2006 1:38 pm
by SCUBA_STEVE
i would say 50/1 mix
got a 9.9hp johnson with that

zort

Posted: Sun May 21, 2006 4:12 pm
by BLR
If'n I remember correctly........been a long time. I think 25-1 might be the mix.........local dealer would probably know for sure....

oil gas mix

Posted: Sun May 21, 2006 5:57 pm
by Mountain Man
I found a couple of web sites for you to check out. I read that it might say under the cover of your motor. Anyway check these sites and more oil is usually better than less. :)

http://www.maxrules.com/fixfaq.html#manual

http://www.outboardrepairs.com/oil_mixture/

Posted: Mon May 22, 2006 10:29 am
by Woodsman
I checked on a boating forum I am also a member of & all searches recommmend a mixture of 24 to 1 for your motor.

Good Luck

Help

Posted: Mon May 22, 2006 11:55 am
by fishin loon
I don't mean to contradict anyone and I am not a expert. but I do repairer older models of engines and I have a service manual for 1956-1970 Johnson/evinrude outboards It doesnt give the exact gas to oil ratio but the whole book is full of pictures of 50:1 oil cans. If this helps I am glad .If you need any info out of the book let me know I can scan and send to you or anyone else who needs it.

Paul Lavoie

Fishin Loon

Re: Help

Posted: Mon May 22, 2006 5:38 pm
by Woodsman
fishin loon wrote:I don't mean to contradict anyone and I am not a expert. but I do repairer older models of engines and I have a service manual for 1956-1970 Johnson/evinrude outboards It doesnt give the exact gas to oil ratio but the whole book is full of pictures of 50:1 oil cans. If this helps I am glad .If you need any info out of the book let me know I can scan and send to you or anyone else who needs it.

Paul Lavoie

Fishin Loon
Paul I believe I have the same manual from Seloc.
As you stated it doesn't mention the gas/oil ratio but does show the 50:1 cans in various places. As they did not mention the ratio outright this caused me some concern which lead to further research.
Apparently from 1960 thru 1964 Johnson/Evinrude converted from some bronze sleeved bearings to all ball bearings. The year of the change varied on different motors. For all pre 1960 motors 24:1 is the recommended mixture. The bronze sleeve bearings require the higher oil mixture.
The power head diagrams show the difference. The bronze sleeve bearings are reffered to as cams or sleeve bearings and liners.
Hope this helps clear things up.

Best Wishes

Posted: Mon May 22, 2006 10:50 pm
by Jebby
great info guys... thx... currently i have 32 :1 in it but im gunna add some... its getting an ew impeller in it now but i will be using it heavily this weekend.... cant wait to try it out.... im thinkin the 24:1 that u guys said sounds good... just hope it dosent leave a slick cuz i dont want to hurt the water system... thx for the help.

jebby

Posted: Wed May 24, 2006 8:44 am
by lars56ca
Jebby...here's something you might want to consider when deciding what ratio to use for your outboard. I've got a 1955 7.5 Evinrude (still runs like a top) that requires a 16:1 ratio. To make a long story short, I mix it at 24:1.
I'm told the reason for this is due to the fact that todays 2 stroke oils are so much better than they were in the 50's. I've probably put 50 to 60 hours a year on the motor and have'nt had any problems yet.

Posted: Wed May 24, 2006 10:32 pm
by Jebby
thx great to know... i have 32:1 in it now but im thinking of goint to 24:1 hope it dosent gum up my carb... if its to heavy ittl let off a lot of blue smoke wont it?
thx
jebby