I have a 3W 106 that has compression releases. I want to take out the compression releases. When I do what should I plug them with? Since they are the same size and thread as a spark plug I could just plug them with a spark plug. If I do that will it lower the compression too much?

Lowering the CR will not be a problem, and probably allows you to run US regular gas, which is a bit inferior to Europe gas. (we get what you pay for, your gas is a lot cheaper!)
Fuel and engine efficiency will suffer slightly though.

Pe,

I hate to tell ya, but U.S gas now costs more per gallon in many places than European and British gas. At least at any international military installations. Seems the gas companies finally have been able to acheive international price parity after all.

the true price per gallon in the uk is cheaper when you remove all the stupid taxes on it.maybe you should all get together and try dumping something in the local harbor----uh like tea lol

as for your 106 remove the releases and install plugs,the engine will run just fine on regular 87 octane pump gas as this is what it was designed to run on .high octane in these engines is bunk,they don't have the high timing needed for high octane gas

Pe, our gasoline is lacking in detergents and has 10% ethanol added. I don't know how our octane rating system equates to the european standard, we have three grades, low, mid, premium. What would the typical 3W 75cc engine require in terms of fuel octane to avoid preignition?

Mike

We have two gas qualities (mainly)
Stanfard is 95 research octane, leadfree
premium is 98 RON leadfree
Deduct about 5 octane numbers for US PON (pump octane) gas, for better gas stock qualities, deduct about 3 octane points.
European engines are made for standard EU fuel, which is about 90 PON in the US. That is premium gas! Anything less, and one walks the thin line along the abbys.
We pay about 1.50 euro for a liter standard gas, which is ~6.00 euro/gallon. At current dollar rates, that be $9.00-$10/gallon, give or take a little.
The trip to the field guzzles more money than the plane, so it is no use to use lesser quality gas. Only premium will do, even in engines designed for low octane fuel. They will not run better, but at least the engines designed for premium will not get hurt! Running more octane does not hurt. Running too low octane will destroy your engine in time. To me, this is a no-brainer. Get premium gas whenever you fill up for our toy engines.