JLG 330 CRT gas/propane not starting and lacks power

[Gentleman Rancher]

I just bought a used JLG scissor lift las week It is running on gas. I noticed when I got it home it would take it a 2-3 attempts to fire up. Then, as I used it it seemed to lack power, especially in slo mode and backing up. In fact at one point after it would not move backward in slow mode, I put it in fast mode and it then backed up. All of this was on a level surface.

This weekend I attempted to start it, and again it would not fire up. It cranks and cranks, but will not start. I do not see a choke on it any where, and it is about 70 degrees outside.

Does anyone have experience with this ? By the way, it does have plenty of gas. Thank you.

 

[Txhayseed]

What motor a gas kubota ? Last service ? Fuel filter change..alot of times people also add an inline filter that gets over looked. It should have a choke that is actuated via a pull soleniod. I would start with the basics first. Spark and fuel and see if you got those. Then we can help you hone in from there if you got those.

 

[Txhayseed]

Does your set up look like this ?

 

[Gentleman Rancher]

Sorry for the delay. I just now saw your response. Thank you. No, I have not been able to fix the issue yet. I have replaced the controller/joystick. It did nothing. My set up looks similar to your picture, but not exact. Would a pic help ?

 

[Txhayseed]

Dual fuels with some miles can be a pain. Carbs varnish etc there should be a choke button on the box. Hit it with brake clean, carb cleaner ect down the throat of the carb and see if it fires off. That will give you a quick spark or fuel diagnoses. Low power could be from low engine rpm to bad drive motor or voltage from the stick to the board. Once you get the engine side sorted and running right you can go from there

 

[willie59]

Have you tried running it on propane since it's dual fuel? I'm not spark engine guru, but one thing I've learned for damn sure is ethanol gas murders carburetors on engines that sit for extended periods of time. Stick a propane tank on it and see if it runs properly. There's always a chance the propane system is wacked as well, I've seen that before, but hey, it's worth a try. If it runs proper on propane then you have a better idea of what to do.

 

[Gentleman Rancher]

I have the propane hooked in. However, the exhaust smells like it is still running on gas. It still takes a while to cold start it, but it is running now. The problem is still with the backing up in low speed it wont move, and if I have had it running for 20 minutes it lacks power. Wont make it up a hill or even over the transition from the street to driveway (slight curb). I have replaced the joystick assembly but still no improvement.

 

[Gentleman Rancher]

Also when i replaced the joystick assembly it included a new potentiometer. Txhayseed's comment about the drive motor sounds like something I would like to look into further. However, I beleive this unit has 2 or 4 drive motors. How would I know which one to look at ? Also, is it possible that it could be a clogged H fluid filter ? Thank you for all of your help.

 

[Txhayseed]

If you start loosing power as the hydraulic system starts to warm up that's usually a good indicator that a you have a hydraulic issue with a drive motor. As fluid gets hot and thinner the motor will start bypassing internally. You might try draining and replacing the fluid but at this point a fluid change might not do much good. As far as finding the culprit motor/motors you would need to get it to the point where it stops moving like you described then pull the case drains off and see what they are returning to the tank. A high volume of return from the case drain is a good indicator of a bad/failing motor

 

[Gentleman Rancher]

Thank you. It is started. Where do I find these case drains ?

 

[Txhayseed]

Case drains would be the smaller lines on the motor.. Usually a 3/8 or 1/4 line in this case