The gallon referred to, to= 5 litres is a UK 8 imp pint gallon as the more accurate measurement is 4.54 litres to 1 Imp UK gallon. Am I correct in the thinking that your US gallons are 6.6 imp pints? if in that case you mixed with 5 litres of fuel the ratio would be even weaker/ thinner ie even less than your 70/1possibly in the region of 85/90/1 ratio as you would have 9pints of fuel instead of the 6.6 pints; assuming your gallon is 6.6 pints. I am not conversant with your oz mixing quantities as I/we use milli litres to litres or a required % ie 2% = 50/1 3% =33& a bit /1 etc If it was me I would run more oil especially in the Dolmar with it being new. I run 32/1 in all my kit but that"s me old fashioned, but I would advise no less than 50/1, the company I work for has 250 litre drums of mix oil & i decant 5 litres & use a measuring jug to work out my oil/fuel mix ratio"s
Basically, yes. All the smaller containers here are 5 litres=1 Imperial gallon. It is also why we never call a bottle of Rum here a 'fifth', as 750ml is a fifth of a US gallon. Using metric makes is very easy to mix ratios.
This leads me to a different point. We are now seeing more and more strato chainsaws. And we are hearing from the field that these saws are using less fuel for the same amount of work. Husqvarna and Stihl say it can be as much as a 20% improvement in fuel economy. And we're also hearing the same for M-Tronic and AT saws. This is all fine and dandy. Well, except we are also seeing(at least in Europe, according to some techs I know) a lot of young saws(550's and 261's mainly, and recently a few 365XT's) die early deaths due to bearing failures. This is purely anecdotal, but I suspect the strato charging may be having more of an effect than simply better fuel economy. After all, if you are seeing a 20% less fuel used per tank, that also means you are seeing 20% less oil usage. 50:1 is already 2% fuel to oil ratio, vs 3% at 32:1 or 2.5% at 40:1. But a strato that gets 20% more fuel economy with a 50:1 mix is likely running close to 60:1 as far as the crank bearings are concerned if you consider the fuel/rpm or fuel/run time ratio vs the previous generation. As I recall, plenty of saws running at 32:1 seized as well. I'm not sure it's a great idea to make it any easier to lean out a saw - not at today's prices. Just a thought...
