tyce
Well-Known Member
i have a old yamaha 25 outboard, does anyone happen to know the correct oil mix ratio.
thanks in anticipation
thanks in anticipation
yamaha oil mix
- Thread starter tyce
- Start date
bendyone
Well-Known Member
Depends how old could be 50/1 or 100/1
Gordonmc
Well-Known Member
Safest to run on 50/1.
My Mercury book said 100/1 but received wisdom is that 50/1 will prolong an old motor's life. It doesn't smoke and starts on the second pull - always.
My Mercury book said 100/1 but received wisdom is that 50/1 will prolong an old motor's life. It doesn't smoke and starts on the second pull - always.
billcowan
Well-Known Member
NO NO NO - must use correct mix.
not enough oil = engine wears out
too much oil = less petrol = engine runs weak = hot = burns plug & piston
If your yam has been made in the last 20 years, then 100/1 sounds correct, but check
Mind you, if you only make short trips (½ mile) then it probably dont matter. The thing will die of corrosion first as have my last 2 yams (2hp both 100/1)
Grat engines. one thing though, at the end of the season, run it in your raiwater barrel to get rid of the salt, and use any left over fuel for making molotov cocktails, cos of evaporation of the lighter fractions, it will have become very "rich" and sooty burning by spring.
not enough oil = engine wears out
too much oil = less petrol = engine runs weak = hot = burns plug & piston
If your yam has been made in the last 20 years, then 100/1 sounds correct, but check
Mind you, if you only make short trips (½ mile) then it probably dont matter. The thing will die of corrosion first as have my last 2 yams (2hp both 100/1)
Grat engines. one thing though, at the end of the season, run it in your raiwater barrel to get rid of the salt, and use any left over fuel for making molotov cocktails, cos of evaporation of the lighter fractions, it will have become very "rich" and sooty burning by spring.
billcowan
Well-Known Member
NO NO NO - must use correct mix.
not enough oil = engine wears out
too much oil = less petrol = engine runs weak = hot = burns plug & piston
If your yam has been made in the last 20 years, then 100/1 sounds correct, but check
Mind you, if you only make short trips (½ mile) then it probably dont matter. The thing will die of corrosion first as have my last 2 yams (2hp both 100/1)
Great engines. one thing though, at the end of the season, run it in your raiwater barrel to get rid of the salt, and use any left over fuel for making molotov cocktails, cos of evaporation of the lighter fractions, it will have become very "rich" and sooty burning by spring.
not enough oil = engine wears out
too much oil = less petrol = engine runs weak = hot = burns plug & piston
If your yam has been made in the last 20 years, then 100/1 sounds correct, but check
Mind you, if you only make short trips (½ mile) then it probably dont matter. The thing will die of corrosion first as have my last 2 yams (2hp both 100/1)
Great engines. one thing though, at the end of the season, run it in your raiwater barrel to get rid of the salt, and use any left over fuel for making molotov cocktails, cos of evaporation of the lighter fractions, it will have become very "rich" and sooty burning by spring.
billcowan
Well-Known Member
ugh - seeing double - msh be somethin i drunk
LORDNELSON
Well-Known Member
I seem to remember that for my 2HP Yamaha the book (which is on my boat and so I cannot refer to it) says 1:100 for pleasure users and 1:50 for commercial users. For the last 7 years I have used mine for pleasure with 1:50 mix and it is still going strong! When I have dissembled it to clear the salt out of cooling passages there is a very satisfactory amount of oil evident around the piston.
jerryat
Well-Known Member
Yes, I agree. I was VERY strongly advised by the engineer from whom I bought my Mariner to use 50:1 not the 'recommended' 100:1. He was adamannt that the engine would last considerably longer. I sold that one after 17 years and it was still going strong.
I run my current Yam on 50:1 also, so hope that'll last at least as long.
Cheers Jerry
I run my current Yam on 50:1 also, so hope that'll last at least as long.
Cheers Jerry
cliff
Well-Known Member
Let me think this one through.....
100:1 = 100drops of petrol and 1 drop of oil
50:1 = 100 drops of petrol and 2 drops of oil
richer oil mix = leaner petrol mix (O.K.) = over heating and burning of the piston - NO way on earth will that happen by running on 50:1 instead of 100:1 - Stop scaremongering.
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo
100:1 = 100drops of petrol and 1 drop of oil
50:1 = 100 drops of petrol and 2 drops of oil
richer oil mix = leaner petrol mix (O.K.) = over heating and burning of the piston - NO way on earth will that happen by running on 50:1 instead of 100:1 - Stop scaremongering.
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Skype id:cliffillupo
BrendanS
Well-Known Member
wanna bet on how many people can measure that accurately anyway?
cliff
Well-Known Member
Only us metallurgists (or should that be alchemists) probably - mind you we can also tell a virgin blonde from on old ore /forums/images/graemlins/wink.gif
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“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo
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Skype id:cliffillupo
Joe_Cole
Well-Known Member
This one keeps coming up on the forum.
All I can say is that I use 100:1 and I've not had any problems either. I suspect that engines suffer more from corrosion, immersion and damage (from accidents; hitting the bottom, dropping etc) than from internal wear.
All I can say is that I use 100:1 and I've not had any problems either. I suspect that engines suffer more from corrosion, immersion and damage (from accidents; hitting the bottom, dropping etc) than from internal wear.
BrendanS
Well-Known Member
While you're here. can you take a look at the 'prop pox' thread here. Suspected dezincification. Photo's on the way. I know a fair amount, but not an expert.
cliff
Well-Known Member
Re: prop pox
Brendan, I was avoiding that one simply because I answered a similiar query before from a pure metallurgical stand point and was contradicted by a numebr of forumites who it turned out knew SFA about metallurgy / corrosion but seeing as you asked I'll have a look and see if I can offer some words of wisdom.
----------
“Artificial intelligence is no match for natural stupidity”
Skype id:cliffillupo
Brendan, I was avoiding that one simply because I answered a similiar query before from a pure metallurgical stand point and was contradicted by a numebr of forumites who it turned out knew SFA about metallurgy / corrosion but seeing as you asked I'll have a look and see if I can offer some words of wisdom.
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Skype id:cliffillupo
