I hope this is the right forum for this

[etpm]

My son has an old boom truck, maybe 1960s something vintage. Telsta brand. It uses a generator to power the boom hydraulics, extension and positioning motors. In the generator manual it has directions for converting from gasoline to propane operation. The manual says to put a tee in the gasoline line and feed the tee with either gasoline or propane. When feeding with propane the gasoline valve is shut off and the propane is fed through a regulator and a needle valve. The needle valve is then adjusted to get the engine to spin at the proper RPM. Anybody ever heard of this? It seems so simple.
Eric

 

[rScotty]

My son has an old boom truck, maybe 1960s something vintage. Telsta brand. It uses a generator to power the boom hydraulics, extension and positioning motors. In the generator manual it has directions for converting from gasoline to propane operation. The manual says to put a tee in the gasoline line and feed the tee with either gasoline or propane. When feeding with propane the gasoline valve is shut off and the propane is fed through a regulator and a needle valve. The needle valve is then adjusted to get the engine to spin at the proper RPM. Anybody ever heard of this? It seems so simple.
Eric

Never heard of it. But I can see where it might work. Propane is denser than air but I wouldn't have thought enough denser that it would lift the carburetor float and close the float valve. ...and unless that float lifts, wouldn't extra propane continually spill out the overflow vent on the carb body?

But other than that it could work. Apparently The needle valve becomes the main jet.
rScotty

 

[WranglerX]

If a little spooked by this, there are actually propane conversion carburetors available....

 

[rScotty]

If a little spooked by this, there are actually propane conversion carburetors available....

It wouldn't spook me a bit. I'll just stand off a ways and hold everyone's beers while you guys start 'er up.

 

[1Mech]

I know years ago, here in Oklahoma, there were quite a few trucks that had dual fuel capability, gasoline or propane, but as I recall, they had special carburetors designed for that.

 

[John_Mc]

I have a portable gasoline powered generator that I converted to run off either propane or gasoline. It was just a kit that I installed. Similar concept to what you described, however, the "T" was not in the fuel line. It was a special fitting that installed between the air filter and the carb. In gasoline mode, it just let the air through normally. To run on propane, you turned off the gasoline fuel valve. A regulator fed propane into a tap on the side of that special fitting.

There was no need to worry about the float in the carb: the float only controlled the liquid gasoline. It does not shut off the air flowing through the carb to the engine.

Ran it for years with no problems until the generator was fried by lightning. I've had a propane conversion kit for my replacement generator for several years, I just have not installed it yet