Propane Conversion

[BIGxMONEY]

I have always wanted to do a propane conversion on my gas lawn mower engine. I've seen different ways of doing it. I've seen people that just put a hose from the propane tank right into the intake. I have also seen people take off the gas line and just run propane into the carburetor. This is thr method I would like to do. If anyone has already done this and has tips or plans on how to convert to propane I would really appreciate that.

 

[reynoldston]

I have also seen people take off the gas line and just run propane into the carburetor. Don't know very much about propane conversions but how would that work? Would you just run it into the air cleaner?

 

[exotion]

I have always wanted to do a propane conversion on my gas lawn mower engine. I've seen different ways of doing it. I've seen people that just put a hose from the propane tank right into the intake. I have also seen people take off the gas line and just run propane into the carburetor. This is thr method I would like to do. If anyone has already done this and has tips or plans on how to convert to propane I would really appreciate that.

Seems like you still need a regulator... don't want to much or to little pressure. And I don't think the carb is necessary carburetors adjust air/fuel ratio needed with liquid fuel. Propane is a airborne gas so just running the airborne gas into the carb wouldn't that be counter productive. Besides carburetors need a liquid to move the float. If you find the right size regulator and use a small take you can run from tank to regulator and a hose to the intake. No carb or air filter

 

[cadet60]

I have alot of experience w/propane powered equipment, and i can tell you what you have mentioned as methods for feeding the fuel are both VERY dangerous. While you didn't mention the type of LP tank, I have to assume you would use a standard home grill tank. First, the pressure of the LP must be reduced from tank pressure (300+psi) to under 5psi. Second, LP is heavier than air and must be mixed w/ intake air as it is introduced into the venturi. After that it could work very well.

 

[BIGxMONEY]

Seems like you still need a regulator... don't want to much or to little pressure. And I don't think the carb is necessary carburetors adjust air/fuel ratio needed with liquid fuel. Propane is a airborne gas so just running the airborne gas into the carb wouldn't that be counter productive. Besides carburetors need a liquid to move the float. If you find the right size regulator and use a small take you can run from tank to regulator and a hose to the intake. No carb or air filter

I realize that I would still need a regulator. I have seen people use a regulator to stop the engine but stopping the fuel. But would it still be possible just to plug in a hose from the propane tank (and regulator) into the carb. Or do I have to put a hose into the intake? Thanks in advance.

 

[lawn mower fanatic]

Here are some pics: http://www.lawnmowerforum.com/members/52water-albums-propane-conversions.html

 

[cadet60]

A couple of other things on this project: fuel flow must be shut off automatically if the engine dies. There are two ways to do this. 1- by engine vacuum turning on a shut off valve when engine is cranked(safest). 2- electrically with an electric shut off valve. This valve needs to be controlled by vacuum, oil pressure, or electrically,i.e engine not running, valve closes. The other thing is as I said before, the fuel and air must be mixed before entering the carburetor. Yes, you can use the existing carb to control enrine rpm, but the gasoline needs to be shut off. There are mixer adapters made which normally mount between carb intake and air filter. BTW, what kind of machine,i.e. make and engine are you thinking of doing this on? I'm just giving general info now, but could give more specific stuff w/ that info. You still need a butterfly in the system to control throttle. Ideal air/fuel ratio is 14:1.

 

[BIGxMONEY]

A couple of other things on this project: fuel flow must be shut off automatically if the engine dies. There are two ways to do this. 1- by engine vacuum turning on a shut off valve when engine is cranked(safest). 2- electrically with an electric shut off valve. This valve needs to be controlled by vacuum, oil pressure, or electrically,i.e engine not running, valve closes. The other thing is as I said before, the fuel and air must be mixed before entering the carburetor. Yes, you can use the existing carb to control enrine rpm, but the gasoline needs to be shut off. There are mixer adapters made which normally mount between carb intake and air filter. BTW, what kind of machine,i.e. make and engine are you thinking of doing this on? I'm just giving general info now, but could give more specific stuff w/ that info. You still need a butterfly in the system to control throttle. Ideal air/fuel ratio is 14:1.

I want to do it on a 4hp Briggs and Stratton. So I would need a valve to shut off gas when the engine is shutoff. I was thinking of a manual valve that could shut gas off to kill the engine by noting fueling it instead of using the normal shut of on the handle.

 

[Mini Motors]

Do it right.

Generator Conversion Kits to Propane and Natural Gas.

 

[cashman]

I've converted several Kohler engines from gasoline to LP. Mostly M8 and M18-20 engines. We replaced the gasoline carb with a gaseous carb and ran a two stage regulator between the tank and carb. The two stage regulator allows you to run tank pressure into one side and then directly into the carb from the other side. The two stage regulator has a primer button for cold starting. We got the regulators and the carbs from Allgas Industries. I have also done some older K series like the Kohler K582 using primary and secondary regulators on them. On those we ran a solenoid valve in the fuel line using voltage from the coil feed to open and close the valve. Usually had to run about an .018 plug gap. Some regultors may require a balance line on the secondary side. The ones I did we ran a line from a balance block between the carb and intake port on the block to the secondary regulator. You need to pay very close attention to the fuel/air mixture with gaseous fuel. If you run too rich a mixture, you could fry the piston. So the mixture and air filter/cleaner has to be kept in top shape at all times. Gaseous fuel does not have the same BTU's that gasoline does, so there will be a slight drop in power with LP. And like was stated earlier, running gaseous fuel into a gasoline carb could be very dangerous!!!