ehh... lucky you bb
but unfortunatly a spark is a spark no matter how it is generated

glad to hear you didn't get hurt too badly though


yes working on these type systems there is always a risk involved so safety is of the utmost priority. Always keep yourself grounded on the lift in some kind of way when dealing with this.

I had an issue where I had to check fuel flow through a Model J. I was outside in the parking lot so I thought I was safe from any kind of ignition source. Because of where the Model J was mounted, the only option was to let the outgoing lp from the regulator bounce off the cold engine block. I applied external vacuum to the VFF-30 & the fuel began to flow. All of a sudden- I saw bright light & smelled burning flesh- then the pain set in. Never knew that static electricity was a factor in propane- almost ended my career.

I had an "incident" once where I had finished a repair in the contactor panel near your right hip on a Hyster stand up reach truck. Sprayed everything clean with chlorinated brake cleaner, put the cover back on- and the supervisor jumped on to return the lift. Imagine our surprise with the giant POOF that occurred when he pulled the forward contactor in!

yea, but you left the customer with a dead fire extingusher they don't know about?
I have even had a spark from a shorted seat switch 'light up my day' when I disconnected the wire from the switch, in a cotton plant, and like the meatball I am, I tried to blow out the little flame on top of the switch. which made a MUCH bigger flame. lived through that one, no one else noticed. always look for the fire extinguisher, and disconnect the battery.
;-)

You guys are scaring me. Never had a propane fire but I did do the brake clean on the motor and then the plug wire jumped a spark to the block. The motor burst into flames. I freaked, yelled FIRE, put it out with a extinguisher, then looked around and no one had even noticed. Cleaned up the extinguisher powder and the customer never knew what happened.
The only thing I can suggest about the Yale is ignition timing. I've noticed that Nissan H20's stumble as you throttle them if the timing is off.

speaking of LPG fires in forklifts, you all probably heard about the "blue rhino" LPG refill plant [for home grill gas exchange tanks] that went up in flames this year [2013] in Florida, but did you see the news video from the beginning of the fire, that showed a forklift, with forks in the air, engulfed in flames, blocking the travel path, in front of a LPG delivery truck, which was the -2nd- thing to catch fire. I never heard an official report yet, but my money is on 'equipment malfunction' in the yard.
On this note, I am wondering about all you experts opinions as to the "best practice" as to where to mount a fire extinguisher on a forklift. [maybe that should be a different thread? since we are getting a long way from fixing Kevin's Yale]
They say when you meet a 'wise older person' you are really only meeting someone that was LUCKY enough to live through their experiences to be able to learn from them, and while I don't claim "wise" I do claim 'only lucky enough to have lived through them'.
and Swoop, -NOW- I know who you are.... lol [just kidding]

War stories, horror stories, real life drama. Yep, the stage is always set.
Ed mentioned that it only takes an errant spark plug miss to ignite the cloud. That is a real possibility, but that is just one source of ignition. A more constant and always present source of "ignition" on a running engine is the alternator. When the engine is running there is always some arcing occurring where the brushes touch the slip rings of the rotor.
And in the case of a forklift that has been sitting in a calm spot overnight inside a building with an LPG leak, the spark that sends the building into orbit will likely come from the arc that occurs in either the key switch, a starter relay, the starter solenoid, or the brushes of the starter against the commutator. Ignition systems that have a distributor cap also produce a veritable "ring of fire" inside the cap on the secondary circuit, older points style distributors of course have the breaker points arcing.
I am not mentioning these things to try and "one up" Ed or anybody else, I am listing them to show other sources of ignition that are "there" so when you try to drive home the dangers of having repairs to LPG fuel systems done by unqualified people.............the risk of fire and/or explosion is very real, almost to the point of being a sure thing....considering all the things that make sparks or arcs on a perfectly normal, good condition (except for that fuel leak) truck.
I stress all these sources of ignition whenever I have to introduce a newbie mechanic to forklift/LPG training and I try to make it sound as though there is a catastrophe just waiting for somebody to light the fuse every time you put your hands on the fuel system.
I also tell them to never ever release LPG from a fitting without first ventilating the work area and if they are using an incandescent work light when releasing LPG, get it out of the work space. Just one drop of liquid LPG striking the glass bulb will shatter it and a fire ball will be the result.

yeah kevin i know about going in after the customer has already attempted to repair a problem, it is surely a headache having to figure out what they botched up and fix that and THEN try and make a diagnosis of the origional problem. I have a customer that does that to me now on a consistant basis... THEN they want to complain about the cost of the repairs after the fact.
I try and explain to them what is happening and they turn a deaf ear to the part about thier tech's botching up the thing before i get to it... its really tough to deal with sometimes.

and bb... flash fires under the hood are no fun, i agree on that... i had a truck do that to me once... cinged my eyebrows and beard when it flashed.. scared the crap outta me too ;o)
So yes, safety is a key factor when dealing with LP systems and also working with flamable sprays etc like electric cleaner and the like. I remember 2 distinct incidents on trucks i was working on... first one was an electric truck, was coding out and i had cleaned the contactors with contact cleaner. I made the mistake of putting the cover back on the rear panel. As soon as i plugged the truck it flashed and blew the rear cover off the truck. Nobody was hurt but it did get the attention of most of the people in the plant lol. An eye opening experience i tell you ;o)
the second incident was cleaning off the engine on an old hyster truck in a cotton mill... i used brakecleaner (big mistake) and didn't get all the cotton off the engine. As soon as i started it the ignition wires arc'd against the engine somewhere and POOF! instant flash fire! man that was scary and the mess from the fire extinguisher was aweful :o/
Was lucky though and it didn't burn up the truck but i certainly learned a lesson there also. DOH!

i guess we all have war stories to tell and the mistakes we've made in the past hehe :o)

Yes edward- lp fires are no fun. I learned the hard way that lp can self ignite from static electricity- almost burnt my face off- literally.

I would document with a the customer's signature that you had informed them of the safety nature of their using 'less than OEM safe' parts.

Customer does their own maintenance( if you call it that...) I only get called when it's something they can't fix or figure out,I told customer to change out the copper line,it is something they installed and told them it wasn't right size or type of line to be using.........

BBforks hits a very good point about the copper line and safety-liability.
I doubt the copper line is rated to LPG high pressures, more likely it is rated to household plumbing pressures and for potable water.
Change it for the proper steel tube or LPG rated flex hose ASAP. Park the truck in the mean time. They/You won't see any LPG bubbles leakage with soapy water, on that line, unless there is a vac. on the VFF30.
Tell them they need training in LPG b4 they hurt someone, not to be mean, but this is exactly why they need the training first.
An LPG fuel engine fire is almost never fun, even if it is exciting. The amount of fuel that spurts out of that hose in 1 blast could easily envelope the entire forklift in flame, with only a missing spark plug fire to ignite it.

It sure is hard to diagnose & fix something when you're fighting the maintenance crew.

When my customer does have a maintenance man/crew, I always look at what they've done before I diagnose anything. Everything has to be put back to factory standard before any repair work can begin for a couple of reasons- safety- liability & the ability to correctly diagnose a fault without chasing my tail.

every setup i've ever seen like that that has the regulator with the VFF30 filter lockoff has always had a steel line connecting the two. And the size of the line is usually 3/8 size tubing.

Even though copper may work it will probably cause some issues down the road like the line breaking and the size of it also may cause issues down the road. Only time will tell but if the mfg designed it with 3/8 steel line i most certainly would put that back on there.

Update:
returned to customer this AM and everything that was posted here checked out ok....I removed the Model J and replaced it with a COBRA Regulator.....started and ran truck and drove it for over 45 Minutes and it ran good....I did notice one thing while replacing reg.....the customer installed a copper feed line from the VFF30 Lockoff over to the regulator and this line is only about 1/4 inch told the customer they might want to put a bigger line on it..........Will repost if this truck starts acting up again( SURE AS **** HOPE NOT!!!!)

you say it has the air intake through the OHG?
there a flexible rubber hose running from the airhorn to the base of the OHG. We had a brand new truck come in the shop back when i worked for yale that did this very same thing, it wound up being that hose. For some strange reason it was collapsing just enough to change the airflow into the engine and causing it to run very badly. We removed the hose and truck ran great, put it back on and engine would run badly.
Might want to give this a thought and see...
since you say removing the air filter made a drastic change in performance. Also check the airway in the OHG and make sure nothing is stuck in it restricting the airflow.
It sounds like an air flow restriction problem.

Truck is an indoor truck and dosent get outside,it does have the up high intake where air is drawn into air cleaner thru the OHG.....it has a new distributor on it so don't know if side play is an issue....am going to ask if when the reman head was installed if it came with the cam or if the old cam is in it??? Possible cam issue......am leaning also towards the crappy model J I put on a while back being the issue....had that with one other customer recently and a COBRA cleared it right up.

I wanna make a WAG too...
Side play in the distributor shaft...
but I also like the wag of vac. advance sticking, due to; too long of a screw used to hold the vac. diaphragm on to the distributor.
but wait,,,
let me ask you, does this air filter housing have the 'air horn' on the air filter housing intake, (where air first comes in), or does this airfilter housing have an 'up-high' clean air intake.? (?missing air-horn getting filter element too wet?).
And if this truck is ever used outside, can you correlate a connection to rain the day before the miss?

Kevin, you also may want to check your Impco regulator fuel pressure on the test port to confirm 1.5- 2 psi during idle and load. It's always tough to isolate a problem that is intermittent. I think the 5/8 vapor hose from regulator to carb is suspect as mentioned and the PCV valve also should be changed. One last thing, I like to use my ignition tester (alligator clip on one end, slips into plug wire on other) onto a spark plug with a decent gap set on it and make sure it doesn't fade during the stutter. Good luck!!

Kevin, you also may want to check your Impco regulator fuel pressure on the test port to confirm 1.5- 2 psi during idle and load. It's always tough to isolate a problem that is intermittent. I think the 5/8 vapor hose from regulator to carb is suspect as mentioned and the PCV valve also should be changed. One last thing, I like to use my ignition tester (alligator clip on one end, slips into plug wire on other) onto a spark plug with a decent gap set on it and make sure it doesn't fade during the stutter. Good luck!!