How long does the generator take to start?

[dkoldman]

Originally Posted by edavis1009

When I bought our ACE new in 2016 the gen. was really hard to start. After I adjusted the choke and drain the carb every time I use it, it fires right up even if it has not been started for months. BTW mine has a drain screw on bottom of float bowl.

That is the way it is suppose to be, and basically what the OP was asking.

If you are having to prime for 20 - 30 seconds every time you start, there is something wrong the mechanics or maybe even the design of gas line for a particular model. Priming does only one thing and that is force gas so it can ignite to carburetor. If you lose pressure due to changing fuel filter or running out of gas that makes sense; if gas pressure is lost otherwise, I would check to find out why? My money says it due to or related to longs periods of no usage?

[Chateau_Nomad]

I found the answer to start mine instantly... the wife sprays a couple hits of starting fluid into the carb while I crank... fires right up!!

[dkoldman]

Originally Posted by Chateau_Nomad

I found the answer to start mine instantly... the wife sprays a couple hits of starting fluid into the carb while I crank... fires right up!!

That reminds me of the very 1st time I went outside to start the Onan 5500 directly. I just wanted to see how it worked; if I ever needed to. So I pull the green cover and get the flashlight to find the start the button, then I pushed it... and bam the damn thing scared the crap out of me; it started so fast and was really loud. I wasn't ready for that I was glad no one was around to see me, but this picture gives you an idea

[Chateau_Nomad]

Originally Posted by dkoldman

That reminds me of the very 1st time I went outside to start the Onan 5500 directly. I just wanted to see how it worked; if I ever needed to. So I pull the green cover and get the flashlight to find the start the button, then I pushed it... and bam the damn thing scared the crap out of me; it started so fast and was really loud. I wasn't ready for that I was glad no one was around to see me, but this picture gives you an idea

WOW! That's just NASTY!!

[Beau388]

Originally Posted by dkoldman

That is the way it is suppose to be, and basically what the OP was asking.

If you are having to prime for 20 - 30 seconds every time you start, there is something wrong the mechanics or maybe even the design of gas line for a particular model. Priming does only one thing and that is force gas so it can ignite to carburetor. If you lose pressure due to changing fuel filter or running out of gas that makes sense; if gas pressure is lost otherwise, I would check to find out why? My money says it due to or related to longs periods of no usage?

Simple explanation in a month the gas evaporates completely from the carb bowl in the 90-101 F heat. The generator is 22 ft from the gas tank. Takes a while for the pump to suck the air out of the line and fill the carb bowl.

[dkoldman]

Originally Posted by Beau388

Simple explanation in a month the gas evaporates completely from the carb bowl in the 90-101 F heat. The generator is 22 ft from the gas tank. Takes a while for the pump to suck the air out of the line and fill the carb bowl.

That aligns with the Owners manual and would constitute and out of gas condition; which would require Priming to refuel. It could also suggest Operator error, or more like misuse if in fact the priming was required because gas has evaporated. Onan has a clear procedure in manual if the genset is NOT going to be used for lengthy periods or placed in storage.


With that said; keep in mind that the OP says...

It currently has 42 hours on it. I changed the oil and air filter at 25-hours, as per the owner's manual. The rest has been running it for 20-30 minutes under load every month or so, just to exercise it.

Which goes to my argument #2 with Generators that I will never understand and that is WHY do people seem to NOT want to use them but once every blue moon or as little as possible?; and then complain that they are not worth a crap (pun intended) because they never seem to start when they need them?

I would love to see an accurate log with graph of the exact start and stop times along with duration in secs for each start? I average 6 - 7 hrs / month, but my guess is that it prolly should be at least 2 hours per month with full loads with each start being a min of 10 minutes.

[Bob Denman]

Originally Posted by Chateau_Nomad

WOW! That's just NASTY!!

https://www.thorforums.com/forums/at...1&d=1628423516

[ducksface]

It's a lawnmower.
It acts likes a lawnmower.

We have a generator start button on the dash, wife doesn't have to get up to do anything.

My ags has never kicked on. Batteries are charged through the inverter and alternator when the generator isn't running and by the generator when it is running(350a charger is built into my inverter)

We run our generator and our ac anytime it's over 80° or so outside.

Generator cranks for five or six seconds...just like a mower that needs to pump fuel.

3,000 miles on our current drive about and we're going for 8,000 or so. Generator was running all but a couple of hundred of those miles and we anticipate the same for the balance of the trip.

An aside
Generator uses about half a gallon per hour, that's 120mpg at 60mph, 140mpg at 70mph.
But
That's about $1.50 an hour at todays fuel prices...multiplied by the hours you run the gen...per day....

V10 uses .67 gallons at idle.

[Pete'sMH]

Originally Posted by Beau388

Simple explanation in a month the gas evaporates completely from the carb bowl in the 90-101 F heat. The generator is 22 ft from the gas tank. Takes a while for the pump to suck the air out of the line and fill the carb bowl.

I think this simple explanation is exactly right. If I start mine weekly or more often it fires right up like a car. If I’m only starting it for it’s monthly exercise it can take a bit of priming and a couple of tries even though my generator is right next to the gas tank. Nothing wrong and no big deal so long as it behaves consistently and does it’s job.

[dkoldman]

So I think the answers should prolly be restated related to the way the questions was phrase by OP.

OP asked...

I'm not sure if this is normal or not, but when I go to start my gasoline Onan 4000 genny, it cranks for a good 10-seconds before it finally lights off. Is this normal, or is there something I should do to fix it?

and...

Interesting. During my walk-thru with the dealer, he told me to hold it until the light comes on. I also noticed that the light goes back out after several seconds of holding it. I assume there's a pressure switch in the fuel line that stops it once fully primed, but I'm just guessing.

I would say "No" it is not normal the way the genset is intended to be used by the manufacturer (Onan) as there is no pressure switch in the fuel line. If Priming is required, you simply have an out of gas condition due to low or no usage.

The above also explains why I have never had to Prime, but I once recall my RV was at a Dealership last summer in Texas during Covid for 2 months. Unless they ran the genny while there (not likely), or primed before I picked it up (not likely), mine continue to start with no issues or delay.

To OP:
My AGS was installed by Authorized Dealer after I bought the RV. I remember working with Onan directly on what is required (parts wiring etc.). If you call them one thing that they made emphatically clear to me is that the #1 reason for failures of generators is due to low usage. To prove it they stated as long as I had the EC-30 installed by an Authorized Dealer, they would extend the warranty tied to Genset because in their words customers that own and use the EC-30 systems; had significantly fewer repairs or call in questions. I have never had a warranty issue with either the Onan 5500, or the EC-30. But Onan does return phones calls on questions about it's operations and the programming of the EC-30 (The Manual is pretty good though)

Like the Duck; I use AGS when traveling, but in AUTO mode; so it fires up if the rear of the coach starts to get warm, even though I may be okay up front

At least one weekend a month while at home when I plan to use it, I will put in AUTO mode. Go turn off the breaker for Shorepower as to simulate a loss of power. I marvel to see and hear the Genset kick on, and both ACs fire up automatically. I will let it run at least 2 hours before I do the reverse which is simply turn the Shorepower back on. The Genset will then turn itself back off. As I have said many times, it is my favorite toy on the RV. I use it all the time (7 hrs / month on avg). None of the above impedes me from also using my two 125AH AGM Batteries; when I don't have shorepower or generator available.

[dkoldman]

Originally Posted by ducksface

It's a lawnmower.
It acts likes a lawnmower.

I got this visual of a lawnmower connected to the back of my RV mowing the lawn one Saturday morning. But I can't find a picture

We have a generator start button on the dash, wife doesn't have to get up to do anything.

My wife and Daughter like the AGS because it is really easy to set to AUTO or Quiet Time modes. It is all they have to remember. The system does all of the thinking for them

My ags has never kicked on. Batteries are charged through the inverter and alternator when the generator isn't running and by the generator when it is running(350a charger is built into my inverter) We run our generator and our ac anytime it's over 80° or so outside.

Our AGS never kick on for low batteries while driving; but will kick on all the time when driving when inside Coach temperature is greater than 78 degrees. We made mod; so we can now run the Norcold fridge through inverter when driving.

Generator cranks for five or six seconds...just like a mower that needs to pump fuel.
Ours is 2 - 3 secs but that is my perception, I may have to pull out the stop watch to verify

3,000 miles on our current drive about and we're going for 8,000 or so. Generator was running all but a couple of hundred of those miles and we anticipate the same for the balance of the trip.


An aside
Generator uses about half a gallon per hour, that's 120mpg at 60mph, 140mpg at 70mph.

... and for 80mph?

But
That's about $1.50 an hour at todays fuel prices...multiplied by the hours you run the gen...per day....

V10 uses .67 gallons at idle.

Good stuff, see above comments.

[ducksface]

Took a look just now.
1048 houts on the generator.

[groucho4u]

I saw a lot of good answers, but I didn't see any about installing a gas shut off valve. Or if it has one, use it every time. My onan 4000 needed service 2 times. Once when I cranked too long, 15 second max? And another when I didn't use the valve. When I don't use the valve, it's hard to start, and now it fires right up.

[Wiley1]

Originally Posted by Chateau_Nomad

I found the answer to start mine instantly... the wife sprays a couple hits of starting fluid into the carb while I crank... fires right up!!

A small engine specialist advised me to NEVER use starting fluid on any small engine. They can blow themselves apart.

Why not just use the prime button like Onan advises?
and, it only takes one person.

[Wiley1]

I believe everything the OP is seeing is absolutely normal.

10 to 15 seconds of cranking time seems perfectly fine to me.

Most of us don't hold the prime button down long enough. That will usually reduce the cranking time to 5-10 seconds.

Don't I wish everything in my coach was as reliable as that Onan.

[dkoldman]

Originally Posted by Wiley1

I believe everything the OP is seeing is absolutely normal.

10 to 15 seconds of cranking time seems perfectly fine to me.

Most of us don't hold the prime button down long enough. That will usually reduce the cranking time to 5-10 seconds.

Don't I wish everything in my coach was as reliable as that Onan.

The Normality question comes into play, because the Onan Manual (at least mine) says to only use the Primer bulb when changing fuel filter, or out of gas. If you think it is normal to be out of gas each time you start the Onan, then I would agree it is normal.

I never use the Primer button; so that it why it does not seem normal to me to have to use every time. One should not allow the Onan to run out of gas by simply drying out is my view. I wouldn't think that be good for he carb, that is why Onan has a separate procedure to store the generator when it is known to not be used for some extended period. The latter could avoid gumming up the carb etc.

Note: I state the above in contrast with my Ryobi / Toro small engines for lawn that specifically state to Prime the primer Bulbs 8 times when starting cold which I view as Normal.

[Wiley1]

Originally Posted by dkoldman

The Normality question comes into play, because the Onan Manual says to only use the Primer bulb when changing fuel filter, or out of gas. If you think it is normal to be out of gas each time you start the Onan, then I would agree it is normal.

I never use the Primer button; so that it why it does not seem normal to me. One should not allow the Onan to run out of gas by simply drying out is my view. Onan has procedure to store the generator.

Darn. Now you've made me pull up the Onan QC 4000 owners manual.
It lists a 5-step starting process which I will condense to:

1. Turn off all high-current appliances like A/C units.
2. Prime by holding Stop.
3. Start by holding Start.
4. Allow the generator to warm up for a few minutes.
5. Turn on A/C units and other larger loads.

It does not say what the "normal" cranking time should be before the generator typically starts. But, IMHO, that is a function of how long it has been since the last time the generator was started. Why? Because my Onan generator has a carburetor and a float chamber. One side of the carburetor is open to the atmosphere and the other side leads to the combustion chamber. The longer the generator sits without being run, the less gasoline will be available in the float chamber for starting. That fuel must be replaced, either by priming or cranking or both.

Perhaps your generator starts quickly, without priming, because you run it every time the thought occurs to you.

In my rig, the generator is less than 12 feet from the gas tank.
When the generator is cold, and not used for a several weeks, it takes about 7 seconds of cranking to start after using the Prime function.
Without using the Prime function, it takes up to 25 seconds to start.

I love my Prime button. I believe it exists to shorten the cranking time. Of course it is possible to start the generator without using the prime button, but why would you?

The OP asked whether his Onan is behaving "normally". I believe it is. The manual backs me up.

[dkoldman]

Originally Posted by Wiley1

Darn. Now you've made me pull up the Onan QC 4000 owners manual.
It lists a 5-step starting process which I will condense to:

1. Turn off all high-current appliances like A/C units.
2. Prime by holding Stop.
3. Start by holding Start.
4. Allow the generator to warm up for a few minutes.
5. Turn on A/C units and other larger loads.

It does not say what the "normal" cranking time should be before the generator typically starts. But, IMHO, that is a function of how long it has been since the last time the generator was started. Why? Because my Onan generator has a carburetor and a float chamber. One side of the carburetor is open to the atmosphere and the other side leads to the combustion chamber. The longer the generator sits without being run, the less gasoline will be available in the float chamber for starting. That fuel must be replaced, either by priming or cranking or both.

Perhaps your generator starts quickly, without priming, because you run it every time the thought occurs to you.

In my rig, the generator is less than 12 feet from the gas tank.
When the generator is cold, and not used for a several weeks, it takes about 7 seconds of cranking to start after using the Prime function.
Without using the Prime function, it takes up to 25 seconds to start.

I love my Prime button. I believe it exists to shorten the cranking time. Of course it is possible to start the generator without using the prime button, but why would you?

The OP asked whether his Onan is behaving "normally". I believe it is. The manual backs me up.

If your manual says to Prime every time, then there is Operational differences between an Onan 4000 and the Onan 5500? I will take my view out the equation and share what my manual for the Onan 5500 says.

Note: It actually does tell you after 30 secs of hold the Start button, it will send an error code, and it clarifies to only Prime when out of gas. (it says IF out of gas)

With that said, since OP has a Onan 4000 I will yield; as I assumed they were the same? If my Onan 5500 starts to requires me to Prime every time, I will ask my Dealer about it to see what happened. Especially while it is still under Onan Warranty.

Note: OP did say he was exercising his unit by the manual, and I my RV was at a Dealership for 2 months and it still started right up.

[Wiley1]

Originally Posted by dkoldman

With that said, since OP has a Onan 4000 I will yield; as I assumed they were the same?

No need to "yield". We're not participating in MMA.

Most likely, our two units are nearly identical, except I'll concede that yours is bigger.

My manual is copyrighted 2014. Perhaps they have changed the instructions since then. I suspect that if we were to call Onan and talk to 8 different agents, we would get 8 different answers.

I think each RV owner is going to find the procedure that works best for his particular rig. I have, you have, and the OP will too.

I just wanted to make sure the OP didn't lose any more sleep thinking that his genset might be malfunctioning.

[jerber]

I have a 2016 Thor outlaw with a 4000 jenny and on the last trip coming home none of the appliances work off the jenny.when we got home and plugged into shore power all the appliances work.Is there some kind of transfer switch that I could reset or does anyone have an idea what to look for?Thanks Jerry