Oil Ratio For 2 Stroke Engine

[chownah]

I hope this stays in the general topic forum since the answer might come from any of a number of areas of experience.

I just bought a pump which is powered by an engine which is identical to the engine which powers my weed cutter. The specs for the weed cutter call for a 20:1 mix of two stroke oil to benzene and it came equipped with a one litre mixing bottle marked for 20:1 mixing. The pump specs are confusing and call for a 25:1 in one place and a 30:1 in another and it came with a bottle marked on one side for 25:1 mixing and 30:1 mixing on the other side.

I don't know why the difference and I must decide what to use for the pump. My idea is to use the 20:1 mix. My reasoning is that too much oil will only cause the spark plug to foul (possibly) and this is not an expensive problem to fix....while using a 25:1 or 30:1 mix would provide less oil for lubrication and would either wear out the engine prematurely or even possibly burn it up for lack of lubricant.

Can anyone advise me as to why they would have different mixes for the same engine and also if my reasoning about the problems associated with too much or too little oil is correct?

Chownah

[Jamie]

To be on the safe side, it's always better to run a bit richer...just don't over do it.

[Pink Mist]

I would start at 20:1 and see how you go.

as far as the other issue dont worry about it

[Thumchok]

If it were my engine , I would go by the manufacturers reccommendation , and then some .

Are the spark plugs Identical ?

20:1 shouldn't hurt it .

[Pink Mist]

If it were my engine , I would go by the manufacturers reccommendation , and then some .

Are the spark plugs Identical ?

20:1 shouldn't hurt it .

reccomendations' triplicate

[goldfish]

You seem to know what you are doing. Always go for the stronger mix of oil if not sure. If the spark plug fouls remove and clean with 1200 wet and dry sandpaper. If this is a regular occurance, as in more than once, weaken the mixture

[cdnvic]

Err on the side of the oil. Too much oil will only foul the plugs. Too little can overheat your bearings and seize up. Easier to clean the plugs than replace crank bearings.

[C-sip-degree]

The specs for the weed cutter call for a 20:1 mix

The pump specs are confusing and call for a 25:1 in one place and a 30:1 in another.

I don't know why the difference and I must decide what to use for the pump.

My idea is to use the 20:1 mix. My reasoning is that too much oil will only cause the spark plug to foul (possibly) and this is not an expensive problem to fix....while using a 25:1 or 30:1 mix would provide less oil for lubrication and would either wear out the engine prematurely or even possibly burn it up for lack of lubricant.

Can anyone advise me as to why they would have different mixes for the same engine and also if my reasoning about the problems associated with too much or too little oil is correct?

Chownah

Can't help you with the pump specs and or different mixes on specs?. 'made by who'?

Your idea to use 20:1 mix is fine I would do the same, new moter run it in with a little extra.

Reason is what you have said above correct, plus the cheap quality of 2T oil in Thailand.

Look at it like this:

1 Ltr Gas = 50 ml 2T Oil = 20:1

1 Ltr Gas = 40 ml 2t Oil = 25:1

10ml per Ltr hel_l thats nothing.

I would avoid the 30:1 as 2T oil is cheaper than engine rings.

By a four stroke, next time and you'll never look back.

Happy pumping

cheers

C-sip

[Pink Mist]

You seem to know what you are doing. Always go for the stronger mix of oil if not sure. If the spark plug fouls remove and clean with 1200 wet and dry sandpaper. If this is a regular occurance, as in more than once, weaken the mixture

try soaking the electrode in petrol, light same then use a maggie file to clean, then re-gap to spec.

[chownah]

Thanks all for the advice. I think I'll start with the 20:1 and only increase the benzene if the plug fouls.

The three different mixes all came from manufacturer's specs for the engines which appear to be identical and have the same alpha-numerical designation....I haven't actually looked at the spark plugs to see if they are the same. The 20:1 was for the weed cutter and the 25:1 and the 30:1 were for the pump. I'm wondering (just out of curiosity) if the weed cutter would need more oil because you are likely to be pumping the throttle alot when cutting weeds but a water pump would run at a more or less constant speed once it is set up and running. Anyone know about this?

Chownah

P.S. I would have bought a 4 stroke but the only really small and light pump was a 2 stroke and this pump was meant for small and low volume situations in remote places. I intend to buy a larger 4 stroke pump (probably a Honda) soon. ....Chownah

[Pink Mist]

Thanks all for the advice. I think I'll start with the 20:1 and only increase the benzene if the plug fouls.

The three different mixes all came from manufacturer's specs for the engines which appear to be identical and have the same alpha-numerical designation....I haven't actually looked at the spark plugs to see if they are the same. The 20:1 was for the weed cutter and the 25:1 and the 30:1 were for the pump. I'm wondering (just out of curiosity) if the weed cutter would need more oil because you are likely to be pumping the throttle alot when cutting weeds but a water pump would run at a more or less constant speed once it is set up and running. Anyone know about this?

Chownah

P.S. I would have bought a 4 stroke but the only really small and light pump was a 2 stroke and this pump was meant for small and low volume situations in remote places. I intend to buy a larger 4 stroke pump (probably a Honda) soon. ....Chownah

play it by beer mate

[lannarebirth]

I hope this stays in the general topic forum since the answer might come from any of a number of areas of experience.

I just bought a pump which is powered by an engine which is identical to the engine which powers my weed cutter. The specs for the weed cutter call for a 20:1 mix of two stroke oil to benzene and it came equipped with a one litre mixing bottle marked for 20:1 mixing. The pump specs are confusing and call for a 25:1 in one place and a 30:1 in another and it came with a bottle marked on one side for 25:1 mixing and 30:1 mixing on the other side.

I don't know why the difference and I must decide what to use for the pump. My idea is to use the 20:1 mix. My reasoning is that too much oil will only cause the spark plug to foul (possibly) and this is not an expensive problem to fix....while using a 25:1 or 30:1 mix would provide less oil for lubrication and would either wear out the engine prematurely or even possibly burn it up for lack of lubricant.

Can anyone advise me as to why they would have different mixes for the same engine and also if my reasoning about the problems associated with too much or too little oil is correct?

Chownah

Both my weedwhackers and pumps call for a 25:1 ratio. I made sure my worker understood this and knew the proper way to mix the fuel. So last week I show up with some petrol and mix 200ml of 2cycle oil with the 5 liters of petrol per the directions. Both weedwhackers are fouled now as apparently they don't really like that much oil. It seems my guy has been doing 150ml per 5 liters and he uses the machinery everyday and has had no problems heretofore.

SO, based on my own observations, I would think a little less oil would be OK.

[C-sip-degree]

I hope this stays in the general topic forum since the answer might come from any of a number of areas of experience.

I just bought a pump which is powered by an engine which is identical to the engine which powers my weed cutter. The specs for the weed cutter call for a 20:1 mix of two stroke oil to benzene and it came equipped with a one litre mixing bottle marked for 20:1 mixing. The pump specs are confusing and call for a 25:1 in one place and a 30:1 in another and it came with a bottle marked on one side for 25:1 mixing and 30:1 mixing on the other side.

I don't know why the difference and I must decide what to use for the pump. My idea is to use the 20:1 mix. My reasoning is that too much oil will only cause the spark plug to foul (possibly) and this is not an expensive problem to fix....while using a 25:1 or 30:1 mix would provide less oil for lubrication and would either wear out the engine prematurely or even possibly burn it up for lack of lubricant.

Can anyone advise me as to why they would have different mixes for the same engine and also if my reasoning about the problems associated with too much or too little oil is correct?

Chownah

Both my weedwhackers and pumps call for a 25:1 ratio. I made sure my worker understood this and knew the proper way to mix the fuel. So last week I show up with some petrol and mix 200ml of 2cycle oil with the 5 liters of petrol per the directions. Both weedwhackers are fouled now as apparently they don't really like that much oil. It seems my guy has been doing 150ml per 5 liters and he uses the machinery everyday and has had no problems heretofore.

SO, based on my own observations, I would think a little less oil would be OK.

Lannarebirth

Not my weedwhacker but maybe you need a retune.

If you insist on running lean on the oil, you better have done your homework !

One thing I do know... the worst thing that's going to happen to your engine at 20 to 1 is a fouled plug.

Too lean and $$$

Good Luck

C-sip

[lannarebirth]

I hope this stays in the general topic forum since the answer might come from any of a number of areas of experience.

I just bought a pump which is powered by an engine which is identical to the engine which powers my weed cutter. The specs for the weed cutter call for a 20:1 mix of two stroke oil to benzene and it came equipped with a one litre mixing bottle marked for 20:1 mixing. The pump specs are confusing and call for a 25:1 in one place and a 30:1 in another and it came with a bottle marked on one side for 25:1 mixing and 30:1 mixing on the other side.

I don't know why the difference and I must decide what to use for the pump. My idea is to use the 20:1 mix. My reasoning is that too much oil will only cause the spark plug to foul (possibly) and this is not an expensive problem to fix....while using a 25:1 or 30:1 mix would provide less oil for lubrication and would either wear out the engine prematurely or even possibly burn it up for lack of lubricant.

Can anyone advise me as to why they would have different mixes for the same engine and also if my reasoning about the problems associated with too much or too little oil is correct?

Chownah

Both my weedwhackers and pumps call for a 25:1 ratio. I made sure my worker understood this and knew the proper way to mix the fuel. So last week I show up with some petrol and mix 200ml of 2cycle oil with the 5 liters of petrol per the directions. Both weedwhackers are fouled now as apparently they don't really like that much oil. It seems my guy has been doing 150ml per 5 liters and he uses the machinery everyday and has had no problems heretofore.

SO, based on my own observations, I would think a little less oil would be OK.

Lannarebirth

Not my weedwhacker but maybe you need a retune.

If you insist on running lean on the oil, you better have done your homework !

One thing I do know... the worst thing that's going to happen to your engine at 20 to 1 is a fouled plug.

Too lean and $$$

Good Luck

C-sip

I reckon you're right c-sip. The thing is, he's agot about 2,000 hrs on it using his method, which is the manufacturers suggested lifetime of the unit. Still haven't had to rebuild the engine yet, but it's good to know that only costs 790 baht when the time comes.

[C-sip-degree]

Lannarebirth

What kind of WW do you have.

Can you buy Stihl equipment in Thailand.

Cheers

C-sip