propane lockoff

[rockcraw]

what is the purpose of a lockoff on a propane setup and do you really need to run one. I am running propane on a yota buggy please give me some feedback. I choose this site other than Pirate because alot of the guys on here know what they are talking about!!

 

[altfuel1991]

A lockoff valve is a fuel shut off valve and if so equipped is also the fuel filter for the system. The electric lock off valves are available with and without built in filters. The need to be wired in through and oil pressure switch so it will not be on all the time if someone leaves a switch on or in the event you flip over it will kill the fuel.

Vacuum lockoffs do the same job using vacuum from the engine to open them when starting the engine. That is one less electrical circuit to deal with. All vacuum lockoffs have a built in filter.

The reason you want to use one is that sometimes a piece of debris can go through the fuel and get lodged in the secondary seat(under the lever) in the vaporizer and cause fuel to continue to flow through when the engine is turned off. If the tank valve is still open you can lose a large amount of fuel through this leak and also load the motor up so it will be very difficult to start the next time as well as being a fire hazard if someone happens to throw a lit cigarette close to the exhaust of your rig.

Propane dissipates when it hits the atmosphere but it drops to the ground as it it doing so. If you had a rig leaking gasoline you would make sure to keep anything flammable from being close to it. Give propane the same respect. Propane is the safest motor fuel in existence but still treat it with respect.

Bottom line- a lockoff is foremost a safety device and needs to be on your rig. Don't take a chance on damaging your rig or hurting someone over a part that cost less than $75.00.

I have twenty years in the alternate fuels business and I don't like seeing anyone take unnecessary chances.
If you have more questions call me. I can talk faster than I can type.

Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212

877-403-7827
205-591-2267, fax

205-837-8871 cell

[email protected]
[email protected]
www.alternatefuel.com

 

[twiztedzuki]

not to hijack but i am running without a lockoff because of it starving engine at WOT, it still dies after while of hard throttle and has to be reprimed to fire back up!? seems like reg/convertor starving it now? bought kit used, looks in good working order but new to propane

 

[tbs]

my was doing the same thing i got with Buddy Gamel
Precision Sales & Service, Inc. and we put a dual mixers on and it fix everything.

 

[altfuel1991]

You are running out of fuel because at WOT there is no vacuum so the vacuum lockoff closes. The vacuum hose is hooked to the wrong port on the mixer assembly or the manifold itself. It needs to be connected to a ported source above the throttle blades. It is probably connected to a manifold source right now. Port vacuum never goes away when the throttle blades are open but manifold vacuum will degrease. It only takes about 3" of vacuum to open the lockoff. When the lockoff closes you are sucking all the fuel out of the vaporizer, that is why it takes a few moments to get the engine started back.

By the way on 700hp setups we only use one lockoff valve.

Call me if you still need help.



Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212

877-403-7827
205-591-2267, fax
205-837-8871 cell

[email protected]
[email protected]

www.alternatefuel.com

 

[twiztedzuki]

it was worse with lockoff, i hav no lockoff on my system now, and it rev to to redline but if i let up it dies and has to be reprimed. seems like if i keep tapping the throttle it will idle down, hard to tell in the middle of climb and hav to let out and it dies

 

[smithbuilt]

WE never run lock offs. They seem to restrict flow. I think they are more a safety feature. But it is also a filter. I havent had any trouble without it,so i wont run one. Just my opinion.

 

[altfuel1991]

If the vacuum lockoff is properly installed it will not close at WOT.
Take a look at the photos. This Tim Cantrell's competition rig.
383 stroker, dual mixer setup, 620 dyno'ed horsepower, huge flat torque curve starting at 1800 rpm.
We only ran one lockoff valve on this engine.

A lockoff valve is at the least cheap insurance for you and your rig.

Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212

877-403-7827
205-591-2267, fax



[email protected]
[email protected]

www.alternatefuel.com



[attachment deleted by admin]

 

[rockcraw]

The problem I am having is that when I go to start the truck it want start until i squirt of ether and it fires rite up and runs idles good and when I turn it off I can imediately start it but if it sets at all for more than a few seconds it will not start back until I use just a little bit of ether. I have tried it with and without the lockoff and still the same result I am useing a model j and a CA100 CARB. Any input would be nice thanks.

 

[altfuel1991]

An engine with those components should start almost immediately when cold. The lockoff is definitely not the problem. That is the same setup as about 2 million forklifts in the US.
1. Check for any excessive clearance at the throttle shaft and base plate. If you can move the shaft it will cause a vacuum leak that causes hard starting and a poor idle. Sometimes when the engine gets hot the clearances will tighten up and it will start hot.
2. Check the gas valve assembly inside the mixer for dirt, oil or damaged diaphragm.
3. Check the fuel hose from the vaporizer to the mixer for cracks or degradation(rotting).
4. Check for vacuum leaks at the base plate/manifold. Also check for a bad intake manifold gasket at the head.
5. Check the vaporizer for excessive oil inside as well as worn/damaged diaphragms.

The problem sounds like a loss of vacuum somewhere. Was the mixer and vaporizer new when you got them? I have seen numerous problems caused by used mixers that have worn shafts and housings that make them impossible to dial in or start properly.

When a propane engine is right you should be able to stand outside the rig, hit the starter and have it fire up and settle into a normal idle with no help.

Let me know what you find.

Buddy Gamel
Precision Sales & Service, Inc.
451 64th Place South
Birmingham, Ala. 35212
877-403-7827
205-591-2267, fax
205-837-8871, cell
[email protected]
[email protected]
www.alternatefuel.com

 

[rockcraw]

Yes the mixer is used and was told all the diaphram was changed and I have 2 different mixers and both do the same I will check the other stuff this afternoon and let you know what I find. The more I read I can see its better to buy new stuff than old. Oh when you said check the shaft what exactly are you talking about are you talking about the carb or the mixer.

 

[altfuel1991]

Take the end of the throttle shaft and see if you can move it around in the base plate. Try it with the throttle closed and open. If you can see that shaft moving up, down or side to side then it will suck air right there.

Buddy

 

[rockcraw]

Do you think I should change the intake gasket out could that be my problem. And the shaft seems to be pretty tight. I am going to take and look at the diaphram and see if there is anything wrong with that. Do have any other suggestions?

 

[altfuel1991]

Get it running and spray the ether around the intake manifold and mixer base. If the RPM rises you have found a vacuum leak. Do not spray it up where the mixer can suck it in.

Buddy

 

[rockcraw]

Thanks for all the feedback. Problem solved!!! Had vaccum leak around the carb and diaphram had black stuff all over it had a spare new one all is working good now one more question. What would you set the time at on 22f and on the carb there is a lean and rich mixture screw what does that need to set on?

 

[altfuel1991]

Set your power mixture to the middle(pointing in line with the vapor hose).
You need an adjustable timing light to set the timing. Without modifying the distributor you can set it by taking the engine to about 2500 RPM and set the timing to 30 degrees without the vacuum advance hooked up. Let it idle and see where your base timing is at that point. If it starts ok when hot you should be in good shape.
If you connect the vacuum advance make sure it is connected to the mixer and not the manifold.
Then set your idle mixture (big screw) to get the smoothest idle.
Last set your idle rpm.

Let me know how that works.

Buddy