Can I use Two Stroke Petrol in a four stroke engine

I will try it and report back.
I want to leave the genny tank completely empty of petrol so I can stow it inside ( weight distribution issue).
I will attach a rubber hose to the float chamber with a Tohatsu connector to it, then I can just connect and disconnect my remote OB tank.

By running the carb dry after use as I do with the OB , I should minimise gumming.

I will reduce the tohatsu to 75:1 and run 98 ron.

I can brush the plug once a month, say 3 times during the season, not really a big deal, I used to clean the seagul plug each time I started ( 10:1 ).
 
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I will try it and report back.

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None of the problems suggested are permanant so even in the worst case scenario you can just go back to normal ULSUL perhaps after cleaning jets and using a little Redex. Personally I'm totally unconvinced by the predictions of gloom it'll be fine.
 
Hi DAKA, I am not usually in the habit of getting into forum discussions, but the highly negative attitude here just needs to be addressed. I have been a mechanic for over forty years working on every type of vehicle from bulldozers to gensets and aircraft to marine. I have hundreds of times used two cycle oil mixed gas in small and even large four cycle engines. Beyond a bit of oil in the exhaust and rarely a little plug fouling I have not once seen an engine damaged. 50/1 is a very small amount of oil ratio. There are tens of thousands of four stroke engines with worn rings and valve guides that regularly consume far greater amounts of oil than that. As far as octane is concerned most people do not understand what octane is. It is in fact a measurement of the lack of volatility of the fuel. The purpose of boosting octane is to prevent pre-combustion. A higher octane fuel has additives that lower it's volatility! Not the other way around. Adding oil to gas in no way makes it more volatile so there is little to worry about as far as octane is concerned. Oil does burn slightly hotter than gas, but again at 50/1 it is a relatively insignificant factor. There are actually many that feel that the added upper end lubrication is beneficial, but I will leave that one to the engineers. Very few four-cycles with the exception of the extremely high performance types used in motorcycles have any great need for high octane gas in the first place. It is the two cycle engine that is highly critical in that regard. I actually think the only engine I ever saw actually damaged was a 52 buick I had as a kid in the early sixties. One night we (like a bunch of delinquents) went out syphoning gas so we could go "cruising". Being idiot kids we mistakenly syphoned a diesel tractor. The car had a 16 gallon tank with about 4 gals left. We put 10 gals of syphoned diesel in it. It actually drove for three more days getting weaker and weaker till it finally froze up from a carbon buildup that jammed the pistons at the top of their stroke, yet once the carbon was scraped and the gas replaced it ran fine again. Moral of story is, if you have straight gas use it, a boat is certainly no place to take any chances you don't have to, but don't be super concerned if you have nothing else and need to occasionally use a bit of pre-mix. It is hardly likely to do any real damage beyond a fouled plug. Regards, Les
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Hi Les and welcome to the forum /forums/images/graemlins/smile.gif

Thankyou for your comprehensive reply, i will do as you suggest and carry a gallon of 98 Ron unleaded and if I run out I will use the 2T mix in emergenceis.

Cheers /forums/images/graemlins/smirk.gif

Pete
 
Welcome to the forum as a fully registered member.

I am sure you are quite right with your advice about using 2stroke fuel in 4stroke engines however your explanation of "octane". or more strictly "octane rating" is not right.

The definition of octane rating of a fuel is that percentage of iso-octane in a mixture of iso-octane and n-heptane that has the same antiknock rating as the fuel.

A detailed explanation can be found in Wikipedia

It is not defined in relation to the volatility or the lack of volatility. Nothing could be further from the truth. In fact n-heptane which by definition has an octane rating of 0 and iso-octane which has an octane rating of 100 both have the same boiling point namely 98°C!
 
And the chap who tested that by actually boiling petrol is officially "well 'ard" /forums/images/graemlins/shocked.gif
 
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And the chap who tested that by actually boiling petrol

[/ QUOTE ] How else would you suggest determining the boiling point. Some care and some obvious precautions are needed with highly flammable liquids but otherwise nothing remarkable about it.
 
Hi Vic,

You are of course correct technically /forums/images/graemlins/smile.gif

I did fully understand what Les was saying,
I took it that Les was describing the volatility in the combustion cylinder under compression as I understand the Octane value determines when the explosion occurs (or to prevent it before the spark).

I am pleased he reduced the technical jargon in a way I could comprehend. /forums/images/graemlins/cool.gif

regards
Pete
 
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How else would you suggest determining the boiling point. Some care and some obvious precautions are needed with highly flammable liquids but otherwise nothing remarkable about it.

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Someone once suggested to me that you could boil water in a paper bag, presume petrol would be tricky /forums/images/graemlins/shocked.gif
 
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Someone once suggested to me that you could boil water in a paper bag

[/ QUOTE ] I dont know about a paper bag but if you look back through your Rupert annuals you'll find the instructions for making a paper kettle (Origami) that you can boil water in.

Very non PC now some of those Rupert tales. I like the one where he found the little black koon from Koon Island and how Mrs Bear tried to scrub him clean!
 
[ QUOTE ]
[ QUOTE ]
Someone once suggested to me that you could boil water in a paper bag

[/ QUOTE ] I dont know about a paper bag but if you look back through your Rupert annuals you'll find the instructions for making a paper kettle (Origami) that you can boil water in.

Very non PC now some of those Rupert tales. I like the one where he found the little black koon from Koon Island and how Mrs Bear tried to scrub him clean!

[/ QUOTE ]

I like the one where he met Gypsy Granny, in Oz magazine /forums/images/graemlins/blush.gif /forums/images/graemlins/blush.gif
 
On an older engine I'd say there would be no problem at all - if there is, just clean it up.

But on a new one you will invalidate the warranty if you run it on a non-approved fuel. Save the fuel, suffer the inconvenience for a year until out of warranty, then use it.
 
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