Starting Old Engines

I have difficulty finding true petroleum here In Thailand, It has become that all petrol is ethanol mixed,-- I given up looking.

My deisel pick up also runs on Bio.

The ethanol fuel that I use stands In 2 bikes one big 1987 1400CC and one small 125 --I can not tell what fuel I have in either by driving them. I leave them for months and they start fine.

I have fuel in my outboard remote tank that is 4 years old ,--I expect it to be ok.

This is my experience however I do hear so many people complain their bikes don't run well on it. I have no comment.

Maybe if they left it alone and didn't mix in octane additive, Seafoam and what ever the magazine adverts suggest to make up for the poor quality fuel everyone is convinced that it is.

I have about 1.2 tons of diesel on the boat that has been there for 7 years. The modern engines run fine on it when I give them their 6 monthly run up.

 

If you store gasoline in a jar with a tight lid, it will remain in good condition for a long time. If on the other hand it is left in a tank, particularly if the tank is more empty then full, condensation and oxidation will take place.

Most refineries put antioxidants and gum inhibitors in the fuel now. Also new refining processes make the problem of stale fuel less an issue, especially combined with the high pressure fuel delivery systems of EFI and computer controlled engine management systems.

The reasons for these difficulties are mostly because of the "blends" used by most refineries. These blends are temperature specific, so they'll "vaporize" properly. For example if you by a jug of fuel in the summer and try to use it in the winter, you'll probably have starting issues. Try to get fuels without MTBE or ETBE additives. I'm fortunate to have a "raw gas" supplier near by, which serves the racing and garden equipment community. It costs a fair bit more, but you don't have fuel lines rotting off your chain saws every two years either. I use to replace fuels lines every couple of years before I learned this. A lot of rebuilt carbs too.

It isn't hard to mess up a batch of fuel and most cruisers, that have been to less developed areas of the world, know how well their engines ran after filling their tanks in these places. Water and other "issues" can literally stop you in your wake. Diesel owners know this as well, though it's a different animal then gas, still prone to bad batches and contamination.

If you have stale gas in a modern car, watch what happens to your O2 and other emission sensors, not to mention injectors and pressure regulators, without using a stabilizer. Old engines seem less prone to these problems if they are started regularly and the fuel flows through, breaking up deposits. Not the new stuff, which dislikes pissy fuel.