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Author Topic: petrol oil mix ratio  (Read 2373 times)

gwa84

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petrol oil mix ratio
« on: May 13, 2011, 07:24:08 PM »

hi could all you smart mahemers out there help me work out haw much 2 stroke oil i need to put into 1litre of petrol if the mix is 25 petrol to 1 oil   :-))


chears peeps  :}
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knoby

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Re: petrol oil mix ratio
« Reply #1 on: May 13, 2011, 07:55:19 PM »

1 litre = 1000 ml

1000 divided by 25 = 40

therefore you require 40 ml of oil

 ok2
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Patternmaker

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Re: petrol oil mix ratio
« Reply #2 on: May 13, 2011, 07:58:07 PM »

Hi, 25 to 1 mix is 40 millilitres of oil to 1 litre of petrol.

Mick
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gwa84

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Re: petrol oil mix ratio
« Reply #3 on: May 13, 2011, 09:07:31 PM »

thanks peeps couldn't get my head to work maths is defanetly not my thing lol  :-))
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andyn

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Re: petrol oil mix ratio
« Reply #4 on: May 13, 2011, 10:51:26 PM »

If it's a new engine, add a bit more. You can never have too much oil in them :-))
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gwa84

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Re: petrol oil mix ratio
« Reply #5 on: May 13, 2011, 10:59:34 PM »

thanks that's the mix for run in its 20 to1 after a gallon of fuel has been run throw  :-)) its gonna take a while to get her to full power me thinks
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scoop

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Re: petrol oil mix ratio
« Reply #6 on: May 14, 2011, 12:34:08 AM »

thanks that's the mix for run in its 20 to1 after a gallon of fuel has been run throw  :-)) its gonna take a while to get her to full power me thinks
That mix is ok for a stock motor but if it's tuned run it at 16:1 which is 62 ml of oil made up to a litre with petrol.
I've found that Semi Synthetic oil is best and I use Super Unleaded petrol in my tuned Sikk 27 motor.

Regards
Scoop
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w3bby

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Re: petrol oil mix ratio
« Reply #7 on: May 14, 2011, 09:09:40 AM »

Agree with Scoop, more oil. I run in the 16:1 range as well.

In our 2-strokes the dyno has shown that more oil means more power (up to a limit of course). Ratios of 12:1 are not uncommon.

tmbc

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Re: petrol oil mix ratio
« Reply #8 on: May 14, 2011, 11:04:56 AM »

hi guys
i have a program that works out oil ratio's just sent martin a message to ask if he can post it on the site if anyone wants it pm me ! its an excel document !

mark
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Bill D203

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Re: petrol oil mix ratio
« Reply #9 on: May 14, 2011, 09:22:42 PM »

If it's a new engine, add a bit more. You can never have too much oil in them :-))

Alas Andy you are not correct this time. I know i have blown up 3 engines. If you read the set up instructions that come with a new engine it tells you just how much oil is needed. They don't set the figures just out of the air. If you stick 40ml in a litre of petrol you will not be far out. If the engine is brand new then you must never let it over rev till it has had a few litres though it then building up the rpm slowly Thats what it says so they IE Zenoah must know.
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Patternmaker

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Re: petrol oil mix ratio
« Reply #10 on: May 15, 2011, 08:34:22 AM »

Totally agree with you Bill, I have not and will never use anything less than 25 to 1 on any of my engines.

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scoop

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Re: petrol oil mix ratio
« Reply #11 on: May 15, 2011, 09:42:19 AM »

Totally agree with you Bill, I have not and will never use anything less than 25 to 1 on any of my engines.


Quite right, 25:1 is ok for stock motors, anything less is asking for trouble, not enough oil for lube or that extra bit of cooling. As I said earlier I run my tuned Sikk at 16:1 on High Octane, never had to do anything to it in the last 3 seasons of hard racing apart from a bi-annual change of the silicone sealing rings on the exhaust manifold (routine maintenance), never had the engine apart, I change the plug if it needs it after half a dozen or so races (more routine maintenance), I don't use the iridium plugs just a bog std one, I change the flexicoupling after half dozen races as well  (the new ones don't seem to last as long these days, lose their grip ! ). That's about it, looking forward to another 3 years out of it, and it's pretty quick to boot...just ask Bill  O0 :-))

Cheers
Scoop
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