JLG 60GR boom lift

[dieseldogg]

I've just recently bought a JLG 6o GR boom lift that has seen little use and always has been stored indoors. It appears to be in excellent shape and everything works except for a couple problems that I have encountered. One issue is that when the boom goes above horizontal the engine will drop to a lower rpm like it should but the engine will really struggle as the boom raises and will eventually die at around 20ft. The engine will also struggle and die if I swing or boom in/out while above the horizontal plane. Once the engine dies, the auxiliary power will work the boom in/out and swing but not boom down. I have had to walk down the boom a couple times now and would really like to figure this one out before I break my neck. One other issue is with the drive. I know that 2 whdr machines are limited as far as mobility goes but mine really seams to have no torque. It will go forwards and back and the high speed function seems to work (judging by listening to the engine) but unless going downhill it wont move. Where I am trying to use this machine is level hard packed ground with the occasional slight dip that the machine wont pull itself out of. Any help with any of these issues would be greatly appreciated. Rick

 

[OFF]

I've just recently bought a JLG 6o GR boom lift that has seen little use and always has been stored indoors. It appears to be in excellent shape and everything works except for a couple problems that I have encountered. One issue is that when the boom goes above horizontal the engine will drop to a lower rpm like it should but the engine will really struggle as the boom raises and will eventually die at around 20ft. The engine will also struggle and die if I swing or boom in/out while above the horizontal plane. Once the engine dies, the auxiliary power will work the boom in/out and swing but not boom down. I have had to walk down the boom a couple times now and would really like to figure this one out before I break my neck. One other issue is with the drive. I know that 2 whdr machines are limited as far as mobility goes but mine really seams to have no torque. It will go forwards and back and the high speed function seems to work (judging by listening to the engine) but unless going downhill it wont move. Where I am trying to use this machine is level hard packed ground with the occasional slight dip that the machine wont pull itself out of. Any help with any of these issues would be greatly appreciated. Rick

First thing I would do is make sure your engine RPM settings are correct. You should be at 1800 rpm on low idle, 2400 rpm on high.

 

[dieseldogg]

Thanx, I will check that out and see if correct.

 

[dieseldogg]

Okay, so I got a little frustrated with my lift and decided to do it the old fashioned way and use scaffolding. Soon after I built the scaffold I proceeded to fall off and break my heel. Now that I am able to limp around a bit I would really like to get this machine running properly. As per OFF's suggestion I checked the RPM settings. At idle my RPM is 1600. At idle with the switch flipped to the platform controls I have 1800. At high idle with the boom below the horizontal plane it is at 2400. As soon as I go past the horizontal plane the engine cuts down to 800 and struggles and surges until it dies. Anybody have any ideas what my problem might be.

 

[willie59]

I've never worked on a 60GR dieseldogg, but it sounds like you have an engine problem. Is it possibly a dual fuel machine, gasoline/propane? What engine does a 60GR have?

 

[dieseldogg]

My machine has a 4 cylinder Wisconsin engine that runs on gas and propane. It has only been run on propane for at least 20 years. It seems to run really smooth until the boom trips the horizontal limit switch and then it just bogs right down. Thanx for helping out.

 

[OFF]

Sorry to hear about your scaffold fall dieseldog. What kind of throttle does a 60G have? Is it just a solenoid either on or off or is it an electronic govnernor with a control
box?

If it's just a hi/low throttle solenoid, the adjustments on your engine governor must be way out of wack. Do you have a manual for that engine? (large wisconsin?) If so, run throught
the adjustments. Your engine isn't compensating for changing load.

If it's an electronic governor type, get us a name off it and we'll find you an adjustment/testing procedure for it.

 

[dieseldogg]

The engine is a VG4D Wisconsin. It has a solenoid with a beaded chain leading to the linkage. I have been trying to find manuals for this machine but it seems that the 60g is a very rare machine.

 

[OFF]

The engine is a VG4D Wisconsin. It has a solenoid with a beaded chain leading to the linkage. I have been trying to find manuals for this machine but it seems that the 60g is a very rare machine.

well, the machine may be rare but the engine isn't. I'll send you a manual for it when I get home tonight. Run through the section on governor adjustments. It's not being
allowed to react to load at all. Something is wrong there.

 

[dieseldogg]

Thanks OFF. I appreciate your help. I disconnected the 2 mercury switches today and the machine worked great. Would the second switch be hooked to the drive system? With the switches disconnected the machine actually had some torque and would move around the property quite well while with the switches connected it would barely move out of its own divot. Thanks again OFF.

 

[OFF]

Thanks OFF. I appreciate your help. I disconnected the 2 mercury switches today and the machine worked great. Would the second switch be hooked to the drive system? With the switches disconnected the machine actually had some torque and would move around the property quite well while with the switches connected it would barely move out of its own divot. Thanks again OFF.

One mercury switch will be for high engine, the other must be for high drive. Is your hi drive toggle switch functioning? Those machines have a lot more "torque" in low drive for sure.

 

[dieseldogg]

Ya, my high drive switch is working. I find that if I can't drive through a dip while in low drive I can sometimes put it in high and make it through with a little momentum behind me. Do you know if the air cooled engine is prone to overheating. I used the lift to load plywood on my shop roof today and after an hour or so of constant running in 30degree heat the engine cut out and would not start again. Went back out after dinner and started instantly.

 

[willie59]

4 cylinder Wisconsin air cooled engine, most likely a VH4D, same as used in the 40F. Are they known for overheating? Not that I'm aware of. Being an air cooled engine and you're running it on propane, have you checked to see if the regulator/vaporizer is freezing up (covered with frost)?

 

[barklee]

Check the machine for vapor lock. They like to do that. We figured out how to stop it but i cant remember, been a few years since we had one of those.

 

[dieseldogg]

After using the lift today I checked the propane unit and found it to be quite cold to the touch so I suppose it could have been freezing up after running for extended intervals. I would have never believed that anything could be cold in an engine compartment where everything else is too hot to touch. Another boogaloo surfaced today where when you push the pedal in the platform it will not always rev up unless you activate the drive system first. Any ideas? Thanks to OFF for sending me the engine manuals. I hope to start reading soon.

 

[willie59]

Being an older machine and just to be sure someone hasn't put a coolant heated vaporizer on it, an air cooled engine like yours requires an air heated vaporizer, should have fins that look like cooling fins on it similar to this one pictured, and it should preferably be located in the flow of warm air coming from the engine cooling air. >

 

[dieseldogg]

My machine has definetly had someone change things around over the years. I have 2 small non air heated vaporizers that have exhaust piped into them to heat them.

 

[willie59]

My machine has definetly had someone change things around over the years. I have 2 small non air heated vaporizers that have exhaust piped into them to heat them.

Wow...never seen that before.