Discussion:
towmotor propane forklift continental engine vaporizer

I have a Towmotor propane forklift that quit running. I am new to propane. I can start the engine with starting fluid but itdies as soon as I quit feeding it starting fluid, therefore the problem is not electrical.

I rebuilt the carburetor (Bendix Zenith) but I don't know how to adjust the main valve at the bottom, but that is a minor problem, I think. I have learned that propane does not work like gasoline and it needs to be converted from liquid (solid) to vapor. I removed and disassembled what I think is a vaporizer from the engine where the upper cooling hose fits. There is one adjustment screw on that assembly and there is a water thermostat and one diaphragm. It appears simple. I am thinking that the liquid propane is allowed into the vaporizer by a solenoid valve when the ignition is actuated. I further think that the vaporizer is actually a nozzle that sprays the propane in the carburetor allowing it ignite the propane droplets by allowing the droplets to be mixed with outside air. After the engine starts and warm, the water from the radiator raises the temperature of the propane for better combustion.

AM I CORRRECT SO FAR?

How are the carburetor valves and the vaporizer to be adjusted?

Is there a repair kit available for the vaporizer or can one be purchased used; it seems so simple that I am nervous about its functioning. It would seem that if combustion did not occur immediately after turning the key that the engine would only have liquid propane and not enough air and the engine would flood. Again, I am not familiar with propane and have only used it for grilling or applying roofing materials. Is there a diagram available for the insides of the vaporizer? Other that a spring loaded valve inside the vaporizer, are there any moving parts?

I am assuming that this is a four cylinder flat head Continental engine as I can find not nameplates.

I will appreciate any help.

Thank You ,
Dieter Schmied
[email address removed]
Cincinnati, USA
  • Posted 7 Apr 2015 08:25
  • By dieterschmied
  • joined 7 Apr'15 - 1 message
  • Ohio, United States
Showing items 1 - 2 of 2 results.
on thins carb, you have a "turnbuckle' and it has 7/16" lock nuts, this turnbuckle is a flow mixture adjustment. you will have to find the correct area that allows the truck to start and run , then do fine adjustment to get it just correct. I would suggest that you either get a very "seasoned" {read as "old timer who remembers these"} service tech, or consider updating to a newer machine or at least a newer style of LPG system.
  • Posted 7 Apr 2015 20:19
  • By edward_t
  • joined 5 Mar'08 - 2,334 messages
  • South Carolina, United States
"it's not rocket surgery"
The way a propane system works is somewhat close to whatnyou describdes....it comes out of the tank in a high PSI liquid form and goes thru either a solenoid or vacuum safetynshut off then goes to the vaporizor....the vaporizor usually has engine coolant running theu it,some sit in a cooling jacket in the engine,the liquid heats up and vaporizes to gas and gets its psi resuced down to usually around 1-5 psi and goes to the air fuel mixer where it goes into the engine.
Being that it is a highly flammable sytem it is best if tou have amprofessional look and work on the sytem....anything done wrong could create a huge fire and possible property and personal injury.
  • Posted 7 Apr 2015 11:48
  • By kevin_t
  • joined 2 Dec'10 - 1,301 messages
  • Pennsylvania, United States

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