# Hoping for help w/Onan Microlite 2800 that won't start after oil change



## daveemac (Aug 23, 2020)

Hi, I have an Onan Microlite 2800 gas generator mounted in an RV I recently bought. It was built in 2004 and has very low hours (no hour counter, but looks new).

In preparation for a long trip and some camping, I changed the oil yesterday and checked the air filter, which went fine.

It's been parked, and I haven't started it as often as I should have, but it had an effortless start 6 weeks ago, and it's always started effortlessly since I bought it about a year ago.

Following the oil change, pushing the starter just results in a loud pang! noise, but no turning, and no combustion. Pushing the button immediately afterwards does nothing, and then after a while it resets and makes the pang! noise again when I push start.

I have a Cummins center nearby, and can potentially get it serviced on Monday, but I was really hoping to hit the road Sunday, before the fires in California get any worse and they close highways again. Also, I suspect the generator is still in excellent mechanical health, and I'd rather not pay a lot of money for what I'm suspecting will be a simple fix.

If anyone has any suggestions I'd be most appreciative. Thank you!


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## iowagold (Jan 22, 2020)

check the battery first..
low voltage on the 12 volt dc or a bad terminal connection can make for a no engage starter..
shoot us some video of the sound...
and yes there is a low oil sensor.


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## Dutchy491 (Sep 18, 2019)

Yep, I agree that it's most likely a weak battery. If voltage reads below 12.5 it's time to replace it. However, check for tight connections and especially a good ground connection. Install a battery maintainer on it too.
The next time that you decide to do an oil change I suggest that you run the unit for atleast 15 minutes to warm up the oil. That way when you drain the oil (wait 5 minutes if too hot for you) it will run out quickly and also remove the contaminants that are held in suspension due to the recent operation. Here's a link to a great small engine oil. 4 Stroke Power Equipment: Shop Oil for 4 Stroke Equipment - AMSOIL 
Also, I don't think that you are exercising the generator often enough. Aim for the first weekend of every month for example, and put a load on it, but remove the load prior to shutdown to preserve the magnetism. 30-60 minutes is a good duration. If there is a fuel drain (most Honda engines) on the carb bowl, open it up too and drain the 2 tablespoons that always remain. Best of luck and Let us know what the issue was, Dutchy


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## daveemac (Aug 23, 2020)

iowagold said:


> check the battery first..
> low voltage on the 12 volt dc or a bad terminal connection can make for a no engage starter..
> shoot us some video of the sound...
> and yes there is a low oil sensor.


Paul, thank you very much for your reply. I've got 12.5V on my house battery, and 12.3 on the chassis battery. I"m not sure which one the generator pulls from, still a newbie. I'm guessing either voltage is sufficient though? Fuel tank is just under full btw, and have exactly one qt oil in genny.

Here's a video of the noise. Thanks again for your help, I'd love to get on the road tomorrow early (and save the mechanic expense!).

--Dave

Video of noise:


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## daveemac (Aug 23, 2020)

Dutchy, thanks for your reply, I didn't notice it until after I shot & uploaded my video.

Does the gen draw from the chassis battery? Engine starts right up on first try, but if 12.3 is too low I'll replace it!

THANKS


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## Dutchy491 (Sep 18, 2019)

Sounds like the starter hitting the flywheel but hasn't got enough power to continue turning. Can you boost it with another battery just to see if it will start? Dutchy


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## daveemac (Aug 23, 2020)

Thanks Dutchy. Yes, I can try that, I'll call a friend, but it might take a little while.

In the meantime, I could run the engine and increase the charge on the battery, that would help, right?

The engine has only been run a few times in the last 6 months, so the battery hasn't had much charging time. It's only two years old and has less than 5K on it.


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## iowagold (Jan 22, 2020)

yea a good battery maintainer or a marine battery charger is a good idea on any camper.
click here for the battery maintainer page
and
click here for the other battery charger page

a jump pack is always handy to have around..
the one i use here my cost was just under 500.00... but it is for BIG equipment.
way more pack than most need...

but sure is handy for doing small stuff!!
I love the over kill!!

yea sounds like low voltage drop out...
try a battery load tester on it..
you might find the batterys are bad but the volts look ok.
i had 2 last week like that on 2 month old battery's...
but it has been hot here... hot and super cold is when battery's show up bad..

there is a way a tech can jump the sol on those...
but if the battery is low... that is hard on starters...
low voltage high current thing on dc gear...

try disconnecting one battery at a time to see what battery is feeding the gen dc.

oh yea does the coach have a battery override switch on the sash for the dual battery setup?
the old units did back in the day...


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## daveemac (Aug 23, 2020)

I'm in Sacramento, it was ~100 degrees or so for a couple months, and recently over 105 for almost 10 days, including a few days of 110.

I haven't worried about the chassis battery because it always starts first try, but I see now that I should have been exercising it, especially with the severe temps. I'm a newbie, learning as I go.

There isn't an override switch, but there is a battery isolator which prevents the chassis battery from draining the coach battery.

Battery maintainer and charger are great ideas, I'll order them ASAP.

In the meantime, will idling the engine for a while work to bring the chassis battery charge up significantly? I'd rather not make my friend drive out here on a Sunday if I can avoid it. But he has a charger, and if that's what I need then I'll have him come out.


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## iowagold (Jan 22, 2020)

idle is not as good as maybe 1k to 1.5k rpm.
try starting the gen with the coach running.

is there another start switch by the generator engine??
also there maybe a lock out switch on the covers for the gen set that might not be seated right.
check on that.
it is a safety lock out for when in service mode.


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## iowagold (Jan 22, 2020)

send over your phone number dave


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## iowagold (Jan 22, 2020)

click here for the gen set service manual

page 45 for operation
on start it is press and hold in the start button till it runs.
there is an auto sequince on the start.. but the button must be depressed till it settles down as it has to have output to stay running.


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## tabora (Sep 6, 2018)

daveemac said:


> Here's a video of the noise. Thanks again for your help, I'd love to get on the road tomorrow early (and save the mechanic expense!).
> --Dave


I have that same model Onan. Your battery has plenty of oomph - note how the whole engine shook after the starter engaged... That sounds like a hydro-locked engine to me; try pulling the spark plug and see if it turns over then.


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## iowagold (Jan 22, 2020)

good idea tabora!


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## daveemac (Aug 23, 2020)

Thanks Tabora! So, pull the plug, re-seat it, and try then?


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## iowagold (Jan 22, 2020)

daveemac said:


> Thanks Tabora! So, pull the plug, re-seat it, and try then?


remove the spark plug then try to see if it will turn over.


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## tabora (Sep 6, 2018)

daveemac said:


> Thanks Tabora! So, pull the plug, re-seat it, and try then?


No, just try "starting" it with the plug out... If the motor and generator head spin then, you'll know that the guts of the operation are likely OK. Watch the spark plug hole and see if liquid comes out, and if so whether it is water, gas or oil.


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