What is the gas ratio for a mcculloch 250 chainsaw. I bought it used and don't have the manual.

Margaret, November 2008

I agree. 50:1 with a DECENT SYNTHETIC 2-STROKE OIL (which - for the avoidance of doubt - does NOT mean synthetic car engine oil), will work for any 2-stroke.

phil_saunders@bigfoot.com

Phil Saunders, December 2008

So if you dilute a 50:1 semi-synthetic oil at the ratio you are suggesting you will have a very rich mix causing unnecessary smoke, premature clogging of the exhaust and fouling of the spark plug.

If an oil manufacturer recommends their oil should be diluted at a certain ratio, then that is the only ratio it should be diluted at.

I have posted the same post previously as it appear it is difficult for certain people to understand- maybe that's why I get so many seized 2-stroke engines in my shop because they listen to uninformed armchair experts.

I sell/service/repair dozens of different makes of 2-stroke machines which if I consulted each and every manufacturers handbook everyone would give a different take on the ratio depending on which ratio their "own name" oil happens to be.....and that in turn is dictated by the people who make the oil for them. Every machine that leaves my shop is filled with Stihl semi-synthetc 50:1 2-stroke mix and not ONE have ever had a running problem caused by that mix.....simply because I listen to what the oil manufacturers recommend.

pleasant, November 2008

IF IT IS AN OLD MAC 250 THE RECOMMENDED FUEL MIX FROM McCULLOCH WAS 16:1 WITH SAE30 OIL, BUT WITH TODAYS 2 STROKE OILS A MIX OF 32:1 (32ML OIL TO 1 LITRE OF PETROL IS A GOOD SAFE MIX.

KAP AG, November 2008

or.....

Consult the recommended dilution ratio on the bottle of two stroke oil you are going to use. Always dilute at that ratio and you won't have any problems.

The manufacturer will recommend a ratio, but this is providing you are using the manufacturers own recommended oil- which could be 100:1 50:1 25:1 or even a 20:1 oil. Logically the engine doesn't have a clue what ratio you are putting in, so unless you are using the manufacturers recommended own oil, any ratio recommended by the manufacturer can be disreagarded.

The engine will run exactly the same even if you put neat petrol in, but obviously add too much oil and it will smoke and oil up, and too little oil and excessive engine wear leading to eventual seizing will occur.

If the oil you are deciding to use states 50:1 on the bottle, then dilute it at 50:1 and this will give your engine the correct protection.

A 100ml bottle of 50:1 2-stroke oil is perfect for adding to a 5 litre can of petrol- shake it up and it's mixed.

If you don't require 5 litres, then you can easily obtain a 2-stroke mixing bottle which is suitable for gauging the correct dilution ratio a litre at a time, which is a more suitable quantity for home owner use.

jeez!

pleasant, November 2008

Try looking at the top of the gas cap for the saw...sometimes there's a ratio displayed on the cap.
You may need to clean up the cap a bit to see it if it has become imbedded with sawdust and dirt.

dan, November 2008

Consult the recommended dilution ratio on the bottle of two stroke oil you are going to use. Always dilute at that ratio and you won't have any problems.

The manufacturer will recommend a ratio, but this is providing you are using the manufacturers own recommended oil- which could be 100:1 50:1 25:1 or even a 20:1 oil. Logically the engine doesn't have a clue what ratio you are putting in, so unless you are using the manufacturers recommended own oil, any ratio recommended by the manufacturer can be disreagarded.

The engine will run exactly the same even if you put neat petrol in, but obviously add too much oil and it will smoke and oil up, and too little oil and excessive engine wear leading to eventual seizing will occur.

If the oil you are deciding to use states 50:1 on the bottle, then dilute it at 50:1 and this will give your engine the correct protection.

A 100ml bottle of 50:1 2-stroke oil is perfect for adding to a 5 litre can of petrol- shake it up and it's mixed.

If you don't require 5 litres, then you can easily obtain a 2-stroke mixing bottle which is suitable for gauging the correct dilution ratio a litre at a time, which is a more suitable quantity for home owner use.

PLEASANT, November 2008