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Jlg 40H carb setup?

rbcanaday

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Mar 11, 2015
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72
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Walterboro, SC
Trying to get a jlg 40H running. It has the 423 motor in it and is running on gas. Used lift in ost and ran fine but owner let it sit for two years and it wasn’t getting any fuel. I pulled carb, soaked and put in Carb kit. Not machine will fire up but won’t stay running unless I hold choke almost closed. If I hold choke just right she runs good.
It has the electric choke which I’m not certain we have set right. Also not sure about starting point for air mixture screw.
anyone have any advice on carb adjustment or advice on how get it to run correctly?
 

grandpa

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Oct 15, 2009
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northern minnesota
Some of those carbs were prone to warping where the top bolts to the bottom. Take it back apart and lap the two so they have a perfect fit. Then make sure the mating gasket is in perfect shape. To set the choke, when the engine is cold, loosen the three screws and turn the control until you can see the butterfly for the choke just start to move. That will give you a close enough setting for now. You may have to readjust according to your temperatures you normally start it in.
 

Delmer

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how dirty was the carb? did you clear all the passages? new gas or the two year old stuff?
 

willie59

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Just my opinion, but in my experience, sitting for two years, we've been on ethanol gas for many years now, and ethanol gas will destroy the innards of a carb if they're left not running. I call it alcohol poisoning. Not saying it can't be done, but I've yet to find anything that will properly clean a carb that suffers from alcohol poisoning, best remedy is replacement. And therein is the rub, those machines used a Zenith carb and those things are dang pricey unless you get lucky and find an internet bargain that actually works.
 

rbcanaday

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Location
Walterboro, SC
how dirty was the carb? did you clear all the passages? new gas or the two year old stuff?

the carb was very bad. After an all night soak we still have to work in several passages. Seems all let air through. Cleaned tank and used new non ethonal gas. Maybe some passage is still restricted. Gonna take back apart and see if we find anything we missed.
 

rbcanaday

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Mar 11, 2015
Messages
72
Location
Walterboro, SC
Just my opinion, but in my experience, sitting for two years, we've been on ethanol gas for many years now, and ethanol gas will destroy the innards of a carb if they're left not running. I call it alcohol poisoning. Not saying it can't be done, but I've yet to find anything that will properly clean a carb that suffers from alcohol poisoning, best remedy is replacement. And therein is the rub, those machines used a Zenith carb and those things are dang pricey unless you get lucky and find an internet bargain that actually works.


I’m afraid of that. Had similar issues with few small engines and I replaced those carbs. Of course they were much cheaper. I was hoping since this was a bigger carb we could clean it easier. We will see once we take apart again.
New carb is 675 cheapest I’ve saw. Ouch
 

rbcanaday

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Mar 11, 2015
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72
Location
Walterboro, SC
Can any of you explain the how the lp fuel system works? Does it still go though carb?
Lift has all the lp stuff there but hasn’t been used in a while. Would it be worth trying to run it on lp instead ?
 

willie59

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Can any of you explain the how the lp fuel system works? Does it still go though carb?
Lift has all the lp stuff there but hasn’t been used in a while. Would it be worth trying to run it on lp instead ?

LP is always better than gasoline for those machines. First of all LP is cleaner, you can use it inside buildings. Second, LP doesn't produce as many dirty combustion byproducts that contaminates the engine oil in the crankcase, better for the engine. And yes, the LP system still goes through the carb venturi, the carb is the throttle body for the LP. It's certainly worth a try to stick a tank on it and see if the LP works.
 

Delmer

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Don't forget about the ignition, just because it will run better with the choke, weak ignition is helped by rich fuel also. Any rubber fuel lines? I've seen them swell up inside and choke off while looking good outside.
 

MarshallPowerGen

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Nov 26, 2017
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Northwestern USA
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Since it has a Zenith I'm guessing it's an LRG engine (no distributor)? You can google "Ford 194-287" or I can email the service manual that has all the breakdown and carb adjustments in it (section 3-22/Page 131).

As others have said, ethanol is pretty rough sitting in the old carbs. I've had decent luck soaking in a bucket of non-ethanol gas or mineral spirits and cleaning out with carb cleaner and welding tip cleaners. Also check your linkages for wear that's letting excess air in. If you can get a tank of LP on it and get it running with that (if the regulator diaphragm is good) you'll be better off overall and have an easier time troubleshooting the gasoline side.
 

DirtyHoe

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Jun 18, 2016
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Albany, Oregon
Get a hold of Maggie in the contact tab:
http://www.zenithfuelsystems.com/index.htm

Maggie was super helpful IDing my Zenith carb without an ID tag on my JLG 45HA. Sent me the float, auto choke, and rebuild manuals. Plus the rebuild kit part numbers.
I had to replace my accelerator jet in my 33 model in addition to the regular rebuild.

Steve
 
Last edited:

rbcanaday

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Mar 11, 2015
Messages
72
Location
Walterboro, SC
LP is always better than gasoline for those machines. First of all LP is cleaner, you can use it inside buildings. Second, LP doesn't produce as many dirty combustion byproducts that contaminates the engine oil in the crankcase, better for the engine. And yes, the LP system still goes through the carb venturi, the carb is the throttle body for the LP. It's certainly worth a try to stick a tank on it and see if the LP works.

will any lp tank hook up to the hose? Tank is missing on machine. I have several lp tanks for cooking purposes but wasn’t sure it was same fitting.
 

rbcanaday

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Joined
Mar 11, 2015
Messages
72
Location
Walterboro, SC
Since it has a Zenith I'm guessing it's an LRG engine (no distributor)? You can google "Ford 194-287" or I can email the service manual that has all the breakdown and carb adjustments in it (section 3-22/Page 131).

As others have said, ethanol is pretty rough sitting in the old carbs. I've had decent luck soaking in a bucket of non-ethanol gas or mineral spirits and cleaning out with carb cleaner and welding tip cleaners. Also check your linkages for wear that's letting excess air in. If you can get a tank of LP on it and get it running with that (if the regulator diaphragm is good) you'll be better off overall and have an easier time troubleshooting the gasoline side.

yes it’s is a lrg. The 2.3 motor. Please email the manual section with adjustments. [email protected]
I looked online at the service manual but the only adjustment I saw was for the governor not the carb.
 

willie59

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will any lp tank hook up to the hose? Tank is missing on machine. I have several lp tanks for cooking purposes but wasn’t sure it was same fitting.

Nope, cooking tanks have POL fitting. You need a 33lb tank, they're fitted with the Qcc1 quick connect fitting that should be on the hose attached to the machine.
 

rbcanaday

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Mar 11, 2015
Messages
72
Location
Walterboro, SC
Nope, cooking tanks have POL fitting. You need a 33lb tank, they're fitted with the Qcc1 quick connect fitting that should be on the hose attached to the machine.

so would you agree that if carb has a stopped up jet or something of that nature it could still run good on lp if that system is working correct?
I’m Considering trying the lp and if it runs good that route I can repair or replace carb later.
 

willie59

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Yes, propane has nothing to do with the innards of the carb, the cab only acts as a throttle body for the propane fuel/air control
 

rbcanaday

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Mar 11, 2015
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Location
Walterboro, SC
Yes, propane has nothing to do with the innards of the carb, the cab only acts as a throttle body for the propane fuel/air control

got carb back on and still wouldn’t run. Took out shut off solenoid amd put a plug in it. Cranked up and ran like it should but wouldn’t shut off with switch. Had to kill master switch. put solenoid back on it ran fine until gas was gone out carb. Wouldn’t crank back up. Maybe solenoid is bad. I’d like to check voltage and all first. Solenoid is 140$.
anyone tell me where solenoid gets it power from?
 

willie59

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That's called an "anti dieseling solenoid" and yes it shuts of flow of fuel through the carb, JLG uses it to shut the engine down. That way, when you shut the engine off, runs till it dies, that clears the gasoline from the intake system, now when you switch over to propane there's no mixture interference from gasoline. Make sure that pin inside the solenoid will move in and out easily with your fingers, ethanol gas will cause those solenoids to get stuck. If it moves freely, put a jumper wire from a battery on the wire and ground the solenoid body, see if it clicks and works the pin. If it works, you likely aren't getting a signal on the wire going to the solenoid.
 

OFF

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Sep 30, 2009
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Alberta, Canada
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HD Mechanic
I have one of those carbs, new in the box with a Genie part number number on it. Same engine. Customer changed his mind after I bought it, I got stuck with it. I'd let it go pretty cheap. Let me know if you're interested.
 
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