Generator starting

[canelo56]

When starting my generator on a class C 24 foot motorhome, I notice it stops cranking then restarts before starting. Is this normal or do I need a new battery coach battery? I haven’t had a problem with it starting at all but the cranking completely stops , then starts to finally fire up.

[frank1018]

I have a 2015 class c. I start the gen every thirty days when storing for winter. My rocker lever is held down to the stop position for about 30 seconds to prime the generator. I can hear it click in. Sometimes mine is doing the same thing your is if I do not hold that prime position long enough especially after a cold snap.

[shootist]

A low battery can cause that in a gasoline engine. Not enough voltage while it cranks to fire the ignition.

[THenne1713]

If later model w/ OHV, this can be symptom that VALVE ADJUSTMENT MAINTENANCE Needed; otherwise, it makes battery/ electrical issues possible; can also be too much oil, or stored w/ too much tilt toward head if it smokes on start, or carb float leak diluting oil and raising oil level w/ gas? (=I.e. leaking past rings while stored leaving possible hydraulic lock) Good Luck, advise GEN brand year/ model?

[twinboat]

Small engine magneto ignition systems make there own voltage. Battery cranking voltage has no effect on it. If it cranks at all it will fire the spark plugs.
That's why you can pull start portable generators..

Check all of the battery connections and if clean and good, get the battery tested.

[canelo56]

I think my problem is I’m not holding down the prime button for 30 seconds. It’s more like 5 to 7 8 10 seconds at the most , it always starts usually on the third or fourth turn, but the cranking that stops and then starts. Not sure what’s going on there battery is good. The generator is a Onan 4000 only has 41 hours on it. I will definitely try the prime longer than 10 seconds and time it to 30 seconds like you suggested thank you for the help.

[canelo56]

The generator is a 2021 Onan 4000 with only 41 miles on it. I think my problem is I haven’t been priming it long enough. Thank you for the suggestion because battery is good everything checks out.

[twinboat]

Priming fills the carburator bowl with gas, it has no effect on getting it cranking.

Check the ground on the generator frame to the chassis. The often use sheet metal screws that loosen.

[THenne1713]

re: OHV VALVE ADJUST, in many affects AUTOMATIC COMPRESSION RELEASE; and EX valve too loose causes loss of ACR. I have seen the kickback from loose valves jam the starter gear, break starter mounts and bolts and even snap the shaft on a starter, but properly adjusted, spins fast and starts easy.

[twinboat]

Originally Posted by THenne1713

re: OHV VALVE ADJUST, in many affects AUTOMATIC COMPRESSION RELEASE; and EX valve too loose causes loss of ACR. I have seen the kickback from loose valves jam the starter gear, break starter mounts and bolts and even snap the shaft on a starter, but properly adjusted, spins fast and starts easy.

Do you know that that engine has a ACR ?

[THenne1713]

Being a 2015 Onan 4000, (most likely) a KY Microlite, QG, or similar OHV gas engine, and yes, (most) do have ACR. Granted very low hours for needing Valve Adjust, but there is a youtube on a diesel fail at (50-100hrs?), Onan replaced GEN, and sold unit as scrap; buyer found valve adjust screw had fallen out... simple reassembly and adjust, test run.
it happens, go figure.

[THenne1713]

I just looked up valve spec, while schedule says 250 hrs for adjust, lash is ONLY 0.002", so needs VERY tight IMHO.

[THenne1713]

Edit correction 2021, not 2015= same answer

[canelo56]

No I didn’t know of the ACR but I will check for sure.