muckypup
Well-Known Member
What ratio should I mix 2 stroke oil with unleaded petrol for a yamaha 4hp 2 stroke outboard. I'm guessing at 25:1? I have no manual.
Steve
Steve
Oil mix ratio for 4hp 2 stroke outboard
- Thread starter muckypup
- Start date
sailorman
Well-Known Member
the yammi would have been manufactured by Tohatsu
Tohatsu recommend 25/1 for running-in 50/1 after that
imho dont run on 100/1 if you want a long life from youe o/b
Tohatsu recommend 25/1 for running-in 50/1 after that
imho dont run on 100/1 if you want a long life from youe o/b
Cloven
Well-Known Member
My Johnson is 50:1
Roberto
Well-Known Member
I have a Yamaha 4hp (model 4AC, must have been built around 1986/1987) which runs (fine) at 100:1
sailorman
Well-Known Member
G
Guest
Guest
[ QUOTE ]
I have a Yamaha 4hp (model 4AC, must have been built around 1986/1987) which runs (fine) at 100:1
[/ QUOTE ]
Funny so do I, 87 model, and it runs smoothest and best at 100:1, ran it for a while on 50:1 but it wasn't as smooth, and I don't think as powerful? Perhaps a happy medium would be 80:1? but a pain to measure!
Beats me why some folks think they know better that the manufacturers, about these things? /forums/images/graemlins/smile.gif I mean the manufacturers run these engines to destruction, before they are released onto the market, you would think they would know what suits their engines best wouldn't ya?
To the original poster, in my humble, (well not very), opinion, Yamaha are probably the best outboards in the business, so if I was you, I would do what the manufacturers say, and run it 100:1. It will push out less smoke, smell less and run smoother, and before some twonk says! "Yeah but not for very long"................ mine is an 87 model and it's still going strong after 20 years! /forums/images/graemlins/grin.gif
I have a Yamaha 4hp (model 4AC, must have been built around 1986/1987) which runs (fine) at 100:1
[/ QUOTE ]
Funny so do I, 87 model, and it runs smoothest and best at 100:1, ran it for a while on 50:1 but it wasn't as smooth, and I don't think as powerful? Perhaps a happy medium would be 80:1? but a pain to measure!
Beats me why some folks think they know better that the manufacturers, about these things? /forums/images/graemlins/smile.gif I mean the manufacturers run these engines to destruction, before they are released onto the market, you would think they would know what suits their engines best wouldn't ya?
To the original poster, in my humble, (well not very), opinion, Yamaha are probably the best outboards in the business, so if I was you, I would do what the manufacturers say, and run it 100:1. It will push out less smoke, smell less and run smoother, and before some twonk says! "Yeah but not for very long"................ mine is an 87 model and it's still going strong after 20 years! /forums/images/graemlins/grin.gif
sailorman
Well-Known Member
the manufacturer would be Tohatsu as the make most small o/b engines that are then re-badged.
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
G
Guest
Guest
[ QUOTE ]
the yammi would have been manufactured by Tohatsu
Tohatsu recommend 25/1 for running-in 50/1 after that
imho dont run on 100/1 if you want a long life from youe o/b
[/ QUOTE ]
Don't think so, mine is made by Yamaha, it is the same engine that Mariner bought in for their 4hp unit, and just re-liveried. Tohatsu do make engines (powerheads) and supply them to other manufacturers, (Mariner) as do Suzuki ( to Johnson), but I aint never heard of Tohatsu supplying Yamaha, at least, not when my engine was built. /forums/images/graemlins/smile.gif
the yammi would have been manufactured by Tohatsu
Tohatsu recommend 25/1 for running-in 50/1 after that
imho dont run on 100/1 if you want a long life from youe o/b
[/ QUOTE ]
Don't think so, mine is made by Yamaha, it is the same engine that Mariner bought in for their 4hp unit, and just re-liveried. Tohatsu do make engines (powerheads) and supply them to other manufacturers, (Mariner) as do Suzuki ( to Johnson), but I aint never heard of Tohatsu supplying Yamaha, at least, not when my engine was built. /forums/images/graemlins/smile.gif
G
Guest
Guest
[ QUOTE ]
the manufacturer would be Tohatsu as the make most small o/b engines that are then re-badged.
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
[/ QUOTE ]
Tohatsu do make powerheads for other manufacturers, but not for Yamaha, read my other post, and stick your stupid tongue back in ya head.
the manufacturer would be Tohatsu as the make most small o/b engines that are then re-badged.
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
[/ QUOTE ]
Tohatsu do make powerheads for other manufacturers, but not for Yamaha, read my other post, and stick your stupid tongue back in ya head.
G
Guest
Guest
[ QUOTE ]
the manufacturer would be Tohatsu as the make most small o/b engines that are then re-badged.
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
[/ QUOTE ]
Just a PS......Long life?? 20 years and still going strong not good enough for ya then?
the manufacturer would be Tohatsu as the make most small o/b engines that are then re-badged.
the reseller tells you what you want to hear, no more oily engines so 100/1. want long life use 50/1 /forums/images/graemlins/tongue.gif
[/ QUOTE ]
Just a PS......Long life?? 20 years and still going strong not good enough for ya then?
landlockedpirate
Well-Known Member
I have always run small Yams on 100:1 (Including 2,3, 4, 8 and 15hp's). Been donig it since I got my first engine in the 80's. Only exception is when running new engines in-use 50:1 and it dont half make a lot of smoke.
Every Yam I have ever owned has run great on the 100:1 and never let me down.
Mark
Every Yam I have ever owned has run great on the 100:1 and never let me down.
Mark
alienzdive
Well-Known Member
maybe this thread should have been started as a vote.
After an engine is run in, do you use:
1. 50:1 /forums/images/graemlins/confused.gif
2. 100:1 /forums/images/graemlins/confused.gif
And all forum experts agree to disagree.
However I mix at 50:1,
After an engine is run in, do you use:
1. 50:1 /forums/images/graemlins/confused.gif
2. 100:1 /forums/images/graemlins/confused.gif
And all forum experts agree to disagree.
However I mix at 50:1,
nyx2k
Well-Known Member
if im plodding slowly i use 100-1 and when using 3/4 throttle i use 50-1 . seems the best of both worlds.
Otter
Well-Known Member
That must be a real pain - adding extra oil each time you increase the throttle /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
VicS
Well-Known Member
Never mind what other people run their engines of various make and ages on.
You need to find the correct mixture for the model (and year ) that you have.
A question on the Yamaha & Suzuki at iBoats should get you the correct answer.
http://forums.iboats.com/forumdisplay.php?f=26
BUT be sure to quote the full model details. Namely make, HP, model number, serial number, (I think for Yammies its just the serial number) and the year if you know it.
You should be able to discover the year from http://www.storesonline.com/site/573683/page/599222
My guess is that is unlikely to be 25:1 unless it is very old. 50:1 will be safe option but it might be 100:1. Some manufacturers had a brief fling with 100:1 in the 1980's but later returned to 50:1 for them (advising that any 100:1 labels should be removed.
Check with the people who really know.
You need to find the correct mixture for the model (and year ) that you have.
A question on the Yamaha & Suzuki at iBoats should get you the correct answer.
http://forums.iboats.com/forumdisplay.php?f=26
BUT be sure to quote the full model details. Namely make, HP, model number, serial number, (I think for Yammies its just the serial number) and the year if you know it.
You should be able to discover the year from http://www.storesonline.com/site/573683/page/599222
My guess is that is unlikely to be 25:1 unless it is very old. 50:1 will be safe option but it might be 100:1. Some manufacturers had a brief fling with 100:1 in the 1980's but later returned to 50:1 for them (advising that any 100:1 labels should be removed.
Check with the people who really know.
G
Guest
Guest
[ QUOTE ]
Never mind what other people run their engines of various make and ages on.
You need to find the correct mixture for the model (and year ) that you have.
A question on the Yamaha & Suzuki at iBoats should get you the correct answer.
http://forums.iboats.com/forumdisplay.php?f=26
BUT be sure to quote the full model details. Namely make, HP, model number, serial number, (I think for Yammies its just the serial number) and the year if you know it.
You should be able to discover the year from http://www.storesonline.com/site/573683/page/599222
My guess is that is unlikely to be 25:1 unless it is very old. 50:1 will be safe option but it might be 100:1. Some manufacturers had a brief fling with 100:1 in the 1980's but later returned to 50:1 for them (advising that any 100:1 labels should be removed.
Check with the people who really know.
[/ QUOTE ]
Absolutely right, that's what I did, and got told to stay with 100:1 The original poster says he has a 4hp Yamaha 86/87 model, same as mine /forums/images/graemlins/smile.gif
Never mind what other people run their engines of various make and ages on.
You need to find the correct mixture for the model (and year ) that you have.
A question on the Yamaha & Suzuki at iBoats should get you the correct answer.
http://forums.iboats.com/forumdisplay.php?f=26
BUT be sure to quote the full model details. Namely make, HP, model number, serial number, (I think for Yammies its just the serial number) and the year if you know it.
You should be able to discover the year from http://www.storesonline.com/site/573683/page/599222
My guess is that is unlikely to be 25:1 unless it is very old. 50:1 will be safe option but it might be 100:1. Some manufacturers had a brief fling with 100:1 in the 1980's but later returned to 50:1 for them (advising that any 100:1 labels should be removed.
Check with the people who really know.
[/ QUOTE ]
Absolutely right, that's what I did, and got told to stay with 100:1 The original poster says he has a 4hp Yamaha 86/87 model, same as mine /forums/images/graemlins/smile.gif
ex-Gladys
Well-Known Member
I remember seeing somewhere that the Yamaha warranty for commercial and retial was different... In commerial use they required 50:1 to honour the warranty, in leisure 100:1
ghostlymoron
Well-Known Member
I have a Mariner 4 which is a re-badged Yamaha. The correct mix is 1/100. Mine runs fine at that. Increasing the oil ratio will weaken the mix and mean adjusting the fuel/air ratio. I wouldn't do it.
Cheers,
GM
Cheers,
GM
VicS
Well-Known Member
By a barely perceptible amount i would think.
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artyman
New Member
Yamaha 4hp 4ac model (1980)
I run at 100:1 because not only does it run well but moving the decimalplace 2 places to the left is easy.Incidentally in 1980 leaded petrol was the norm so I add a little additive when I fill my decanting 5 litre can. Anybody else use a leaded petrol additive. My 30 year old outboard is still running well...
I run at 100:1 because not only does it run well but moving the decimalplace 2 places to the left is easy.Incidentally in 1980 leaded petrol was the norm so I add a little additive when I fill my decanting 5 litre can. Anybody else use a leaded petrol additive. My 30 year old outboard is still running well...
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