ScoutLeader
New member
I have a Yamaha 25DM. I was told the mix was 50:1 but inside the engine I have found a label saying 100:1. Should the mix be 100:1?
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Help Yamaha
- Thread starter ScoutLeader
- Start date
jamesjermain
Active member
My Tohatsu - somewhat smaller - is also rated at 100:1 but the guys who sold it to me advised that I stick to 50:1.
There seems to be a feeling in the trade that, while these engines will run on 100:1, there is such a small margin for error, and it is so easy to get a 100: 1 mix slightly wrong, that the risk of damage is too great. A 50:1 ratio works perfectly well but is a little more polluting (and expensive)
<hr width=100% size=1>JJ
There seems to be a feeling in the trade that, while these engines will run on 100:1, there is such a small margin for error, and it is so easy to get a 100: 1 mix slightly wrong, that the risk of damage is too great. A 50:1 ratio works perfectly well but is a little more polluting (and expensive)
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discoduck
New member
Yes 50.1 Outboards run at higher temperature than domestic two stokes,and buy marine 2-st for the same reason.
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mirabriani
New member
For the last three years I have run my tohatsu 3 1/2 on 100:1
I do, however use top quality fully synthetic moto cross oil
Regards Briani
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I do, however use top quality fully synthetic moto cross oil
Regards Briani
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boatmike
Well-known member
The 100/1 mix enables the manufacturer to pass emission tests. As they have pessed these tests on 100-1 they have to recommend this mixture to you. 50-1 will give a better protection to your engine.
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Steve_Bentley
New member
I bought a beautifully reconditioned '93 Mariner 30M from Andy Clark (Bosun's Mate) which is also a Yamaha. He also advised to use 50:1 if getting any thrashy use on rib. It might be cheaper to run 100:1 but as these motors aint cheap to fix/replace either I wouldn't do it!
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ScoutLeader
New member
Thank you all for your help. I will run on 50:1, as the engine is fitted to a Dory and is mainly used on a river as a safety boat I intend to serruptitiously (sod the spelling) give it a good blast at the end of each session just to clear it out.
ps.
I also run Mariner 40's Mec 7.5's, Tohatsu 9.8's Evinrude 25's and in work for restoration are a selection of the British Standard Seagull's. Unfortunately (or otherwise) all the engines I run must be geared so I cannot use the Seagull's (boo hoo)
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ps.
I also run Mariner 40's Mec 7.5's, Tohatsu 9.8's Evinrude 25's and in work for restoration are a selection of the British Standard Seagull's. Unfortunately (or otherwise) all the engines I run must be geared so I cannot use the Seagull's (boo hoo)
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