merc 200 v6

mick c · 08-05-2009, 10:18 AM

can anyone tell me the oil/petrol mix on a merc 200 v6 thanks

wiggy808 · 08-05-2009, 10:19 AM

Hi, I run mine at 32/1 and have had no problems. It will tick over all day without fouling the plugs too.

mick c · 08-05-2009, 10:20 AM

been running 50/1 is this bad

mike k · 08-05-2009, 10:26 AM

Always ran 32/1 on my 2.5 with no problems at all.

FrenchPhil · 08-05-2009, 11:05 AM

I run 3% but will try 2.5% this year. 2% seems a little lean. Do you often over 6k rpm?

bigboy · 08-05-2009, 11:07 AM

This is what I read most of them time:

up to 6k 1:50
up to 7k 1:40
+ 7k 1:32

fullbore · 08-05-2009, 08:17 PM

Quote:

Originally Posted by mick c

been running 50/1 is this bad

Me the same ?

Wayne Kerr · 08-05-2009, 08:36 PM

I've always ran mine at 1:50. I've had no problems!
It may make sence to run more oil, maybe I'll move to 1:40.
As post '6' says, depends on what your doing.

fullbore · 09-05-2009, 08:39 AM

Quote:

Originally Posted by Wayne Kerr

I've always ran mine at 1:50. I've had no problems!
It may make sence to run more oil, maybe I'll move to 1:40.
As post '6' says, depends on what your doing.

Before I changed to pre mix,never needed to top up oil in 1 season, do u no what rate oil was pump through the Pump/oil tank?

Jon Fuller · 09-05-2009, 09:09 AM

Something to consider is, changing the fuel / oil ratio doesn't just change the amount of oil going through your motor.

Jet size is a delicate thing.

When you change the fuel-oil ratio, you also change the overall viscocity of the fuel, and thus the ease with which it passes through the jets in the carbs.

So more oil will thicken the fuel, reducing the amount drawn through the jet, so the engine will actually see a leaner fuel/air ratio.

To really achieve an accurate change in oiling 'and' maintain correct fuel/air, one would need to change the jets as well, so as to maintain the same fuel/air, but increase, or decrease the volume of oil getting into the motor as required.

I'm sure there must be a chart somewhere for choosing jets to suit oil ratio.

Be carefull, because adding oil, with the intention of increasing the engines lubrication for increased durability and life, could actually give you a lean fuel mix that causes a failure. As Alanis Morissette says...Isn't it Ironic.

When I was a kid, a kit was available from the Seagull outboard company to change from the older 10:1 fuel/oil premix, to 25:1. that kit consisted of a main jet, slide needle and a chart showing how much oil to put with a gallon of petrol! The replacement main jet had a smaller orifice for the lower viscocity 25:1 fuel/oil mix. The kit came 'with compliments' from Seagull. (ie, FOC)

fullbore · 09-05-2009, 09:39 AM

Quote:

Originally Posted by Jon Fuller

Something to consider is, changing the fuel / oil ratio doesn't just change the amount of oil going through your motor.

Jet size is a delicate thing.

When you change the fuel-oil ratio, you also change the overall viscocity of the fuel, and thus the ease with which it passes through the jets in the carbs.

So more oil will thicken the fuel, reducing the amount drawn through the jet, so the engine will actually see a leaner fuel/air ratio.

To really achieve an accurate change in oiling 'and' maintain correct fuel/air, one would need to change the jets as well, so as to maintain the same fuel/air, but increase, or decrease the volume of oil getting into the motor as required.

I'm sure there must be a chart somewhere for choosing jets to suit oil ratio.

Be carefull, because adding oil, with the intention of increasing the engines lubrication for increased durability and life, could actually give you a lean fuel mix that causes a failure. As Alanis Morissette says...Isn't it Ironic.

When I was a kid, a kit was available from the Seagull outboard company to change from the older 10:1 fuel/oil premix, to 25:1. that kit consisted of a main jet, slide needle and a chart showing how much oil to put with a gallon of petrol! The replacement main jet had a smaller orifice for the lower viscocity 25:1 fuel/oil mix. The kit came 'with compliments' from Seagull. (ie, FOC)

That`s to much info for a saturday morning for me jon.

bigboy · 09-05-2009, 09:44 AM

Quote:

Originally Posted by Jon Fuller

Something to consider is, changing the fuel / oil ratio doesn't just change the amount of oil going through your motor.

Jet size is a delicate thing.

When you change the fuel-oil ratio, you also change the overall viscocity of the fuel, and thus the ease with which it passes through the jets in the carbs.

So more oil will thicken the fuel, reducing the amount drawn through the jet, so the engine will actually see a leaner fuel/air ratio.

To really achieve an accurate change in oiling 'and' maintain correct fuel/air, one would need to change the jets as well, so as to maintain the same fuel/air, but increase, or decrease the volume of oil getting into the motor as required.

I'm sure there must be a chart somewhere for choosing jets to suit oil ratio.

Be carefull, because adding oil, with the intention of increasing the engines lubrication for increased durability and life, could actually give you a lean fuel mix that causes a failure. As Alanis Morissette says...Isn't it Ironic.

When I was a kid, a kit was available from the Seagull outboard company to change from the older 10:1 fuel/oil premix, to 25:1. that kit consisted of a main jet, slide needle and a chart showing how much oil to put with a gallon of petrol! The replacement main jet had a smaller orifice for the lower viscocity 25:1 fuel/oil mix. The kit came 'with compliments' from Seagull. (ie, FOC)

Never thought about this but sounds logical.

gazza · 09-05-2009, 09:50 AM

As Jon says above + if you run your motor at high revs with load on IE run on the the boat at speed, kill the engine and check plugs, at this point should be medium brown colour, white = too lean, black = too rich.
This how i've always done it anyway with no issues

gaZ

Virtual Insanity · 11-05-2009, 05:47 PM

said 50:1 in my book , works well for me.....