Gasoline Generator Prime switch

[gb73071]

I am having trouble starting my 2017 Leprechaun's generator. Onan 4000. All the literature for the generator talks about holding the start/stop button down to prime. Mine has a separate prime button. I don't remember the sequence for starting. I hold prime until the blue light comes on, let go, the blue light turns off, then I try to start. No luck. Just cranks. Can anyone tell me the sequence for prime and start when there are two different switches?

[raulrio]

I prime mine three or four times before I try the start button. Also, I hold the prime button down a few seconds after the blue light comes on.

[4_Weasel]

Originally Posted by gb73071

I am having trouble starting my 2017 Leprechaun's generator. Onan 4000. All the literature for the generator talks about holding the start/stop button down to prime. Mine has a separate prime button. I don't remember the sequence for starting. I hold prime until the blue light comes on, let go, the blue light turns off, then I try to start. No luck. Just cranks. Can anyone tell me the sequence for prime and start when there are two different switches?

Have you checked the circuit breaker on the generator to make sure it is in the on position? Here is the location.

[wahoonc]

I have the same generator, it can be a bit cranky if it hasn't been run recently.

I hold down the prime button until the light goes out, wait about 10 seconds then do it again. Then try to crank it for a about 5-10 seconds, then prime again. Crank again, sometimes it may take 4 or 5 tries to get it going. Once warmed up it will crank up promptly. Just for the record Onan reccomends running the generator with at least 1/2 load for 2 hours once a month. I usually can get that done when we travel by running the roof air. Winter time I will run the heat pump or electric fireplace.

Aaron

[rmoore0852]

I chased what I thought was a priming issue forever on my 4000. It ended up being the control rod for the choke. This is the rod that runs from the carburetor to the little silver box on the exhaust (top right of the generator). I have found that the heat mechanism inside the box sticks with the rod all the way to the right. If I pull the rod to the left, it unsticks it and the generator starts right up. I only have to do this on the first start of a camping trip. We can stay out for a week and it will start fine every time. I'm thinking its road vibration "sticking" the control rod, but I haven't gotten around to fixing it yet or even opening up the control box.

When priming, if everything else is quiet you can hear the fuel pump clicking. The sound changes when it gets all primed up.

[jrowe0521]

the prime button runs the fuel pump to insure gas is in the carb enough. once the gen motor starts, and the generator kicks in, the generator will supply voltage to the fuel pump as needed. during normal operation, the fuel pump turns on as needed with a pressure switch. I have been told that it is good to run the gen about once a month to keep things fresh. remember, the coach gas tank must have at least 1/4 tank.

[BobHanke]

On most motor homes, the gas line comes from higher on the tank so it can't suck the last quarter of the tank. Make sure you have enough fuel.

[gb73071]

Still can't get it started. It is brand new and only been started during my walkthru. I will go back to check the choke. When I hold the prime down for long I smell gas so maybe flooding. Thanks.

[jrowe0521]

the choke is automatic, I believe.

[rmoore0852]

Originally Posted by jrowe0521

the choke is automatic, I believe.

The choke is SUPPOSED to be automatic. After chasing a priming issue for almost a year I found that mine was sticking. Mine wouldn't start until the vibration of attempting to start the generator would un-stick it. I would crank 20 seconds or so at a time and it would take 4-5 cycles for it to finally start. Once I figured out to pull the rod left so that it moves freely, it starts within about 5-10 seconds of cranking on the first try.

I'm not saying for sure that this is the OP issue, but it sure sounds like exactly what mine was doing.

OP, if you can smell fuel then it is NOT a priming issue. There may be a fuel leak or it may be flooding. A choke stuck completely closed will flood the engine. Right now I can't remember if mine sticks full open or full closed. It sticks to the right, if I pull it left it comes free and the gen starts right up. Anybody remember if to the right is open or closed?

[Cold Lake Kid]

My Onan 4000 is cranky to start when it has been sitting as well.
I'm interested in the comments about the sticky priming rod and I'll have to try the fix rmoore0852 describes, since I have to let my unit sit from the end of October until the end of April, in the cold and snow.
I try to start everything every 3 to 4 weeks during the winter and run it for 15 to 20 minutes.
Thanks for the tip.

[Wolverine 1945]

I have been told by several folks that I did not run mine often enough,,, that's why we had to have carb replaced this Spring,,, even thow I ran it every month this last summer,, this fall we had to have the fuel pump replaced !!!
There are many that claim the problem in ethanol gas !!!
I believe after spend about $800 dollars on a 4 year old Generator,,, that the fuel sys in the 4000 is very weak !!!

[gb73071]

As I originally stated, it is brand new, no chance yet to run it regurally. Thanks for the suggestions but tried them and it still won't start. I have an appointment on Thursday at an RV repair shop. My last RV was diesel and the generator started first try every time. Never had to prime it. So it could be I am just missing a step somewhere. If there is something wrong with it then I will go thru the ordeal of warranty repair when I get home.

[Toyman]

I have the same problem as rmoore on this generator. Several in the past had no problem as long as they were run, under load, frequently, for at least 1/2 hr.

[Wolverine 1945]

Originally Posted by gb73071

As I originally stated, it is brand new, no chance yet to run it regurally. Thanks for the suggestions but tried them and it still won't start. I have an appointment on Thursday at an RV repair shop. My last RV was diesel and the generator started first try every time. Never had to prime it. So it could be I am just missing a step somewhere. If there is something wrong with it then I will go thru the ordeal of warranty repair when I get home.

You will probably end up @ an ONAN service center !!!
Just Google ONAN service !!!
Good Luck !!!

[ActionJackson]

Originally Posted by rmoore0852

I chased what I thought was a priming issue forever on my 4000. It ended up being the control rod for the choke. This is the rod that runs from the carburetor to the little silver box on the exhaust (top right of the generator). I have found that the heat mechanism inside the box sticks with the rod all the way to the right. If I pull the rod to the left, it unsticks it and the generator starts right up. I only have to do this on the first start of a camping trip. We can stay out for a week and it will start fine every time. I'm thinking its road vibration "sticking" the control rod, but I haven't gotten around to fixing it yet or even opening up the control box.

rmoore0852, I have had the same exact issue. Numerous cranks to start. I moved the rod to the left(it did feel somewhat stuck, but moved with minimal pressure) and the motor started up on the first crank. Has anyone seen what is in the silver box atop the heat riser? Would any type of spray lube help. I'm so glad I've seen this thread as I have been cranking my genny over 3-4 times every time for the last 3 years.


When the rod is stuck to the right, I'm assuming that the choke is not operating, hence the reason for multiple cranks.

[Wolverine 1945]

Originally Posted by ActionJackson

rmoore0852, I have had the same exact issue. Numerous cranks to start. I moved the rod to the left(it did feel somewhat stuck, but moved with minimal pressure) and the motor started up on the first crank. Has anyone seen what is in the silver box atop the heat riser? Would any type of spray lube help. I'm so glad I've seen this thread as I have been cranking my genny over 3-4 times every time for the last 3 years.


When the rod is stuck to the right, I'm assuming that the choke is not operating, hence the reason for multiple cranks.

I'll bet if you called a ONAN service center they would answer that question !!
Might be a good place for White Lithium ???

[ActionJackson]

Originally Posted by Wolverine 1945

I'll bet if you called a ONAN service center they would answer that question !!
Might be a good place for White Lithium ???

Yes, maybe white lithium or even WD 40. It's in a real tight area and you can't even see what is in the sivler box. Must be some kind of heat spring that retracts when hot (I guess, that is why I was asking).

[gb73071]

When I originally started this thread I explained this was a brand new RV. So I can't start it to run it every month, like I did with my last RV, because it won't start. I took it to a mechanic today and he determined it was not getting any spark. It's a warranty issue that will have to be dealt with when I get home. Thanks to those who read my question and made some good suggestions on what to try. The priming was working but no spark.

[Wolverine 1945]

Originally Posted by gb73071

When I originally started this thread I explained this was a brand new RV. So I can't start it to run it every month, like I did with my last RV, because it won't start. I took it to a mechanic today and he determined it was not getting any spark. It's a warranty issue that will have to be dealt with when I get home. Thanks to those who read my question and made some good suggestions on what to try. The priming was working but no spark.

ONAN Service Center !!!