Correct way to start Onan 4K generator

Mine (1988) doesn't have the prime feature, but I added a toggle switch inside the generator compartment to energize the fuel pump. I turn it on and listen; it usually takes about 10 seconds (first start of the weekend) and I can hear the pump change sound as the lines become pressurized. At that point, I turn the toggle off, hit the starter button, and it starts within 3-5 seconds. The rest of the weekend/trip, no need to prime.

wa8yxm wrote:
Instruction manual says PRESS STOP till the light comes on (Assumes there is a light) I suggest you hold it a bit longer (15-30 seconds) )

that is usually the key...especially if the generator is a ways from your gas tank...they lose fuel pressure when they are off for a while and it takes a while to get it back...my gas tank is 20 feet away from the generator...about 30 seconds usually does it for the prime...the light comes on at about 8 seconds....not long enough..

My Onan 4k MicroQuiet Generator starts right up from the remote switch now. Usually takes about 5 seconds. We use the RV at least twice a week, so the generator is used frequently, if that makes a difference.

Might want to check the house batteries. Are they old? My generator took quite a long time to start for the first couple weeks after we bought the RV (used), then it just stopped cranking all together. Turns out the house batteries were going bad. New house batteries now, and no issues.

Rotzilla wrote:
I have a 13 model 4k, I usually use the remote start switch inside my camper, crank for 15 sec, pause and crank 15 sec more. If its cold it usually starts on the 3rd attempt.
I do not go out and use the prime function on the gen set, if I did it might start faster, who knows.
Yours sounds similar to mine.

Pushing the STOP is the prime function on my remote.

I have a 13 model 4k, I usually use the remote start switch inside my camper, crank for 15 sec, pause and crank 15 sec more. If its cold it usually starts on the 3rd attempt.
I do not go out and use the prime function on the gen set, if I did it might start faster, who knows.
Yours sounds similar to mine.

DownTheAvenue wrote:
Google is your friend.

Unfortunately, nothing in that manual addresses the OP's problem.

Instruction manual says PRESS STOP till the light comes on (Assumes there is a light) I suggest you hold it a bit longer (15-30 seconds) Then press START. It should start within 30 seconds.. Mine (is bigger than yours) usually does not.

ANother method that I have found effective is this.

Press start.. Just a second or less .. Now wait, like 30-60 seconds. Press again, Mine USUALLY starts within 15 seconds on the 2nd press.

You can combine (Start by pressing STOP. then press START for 1-30 seconds. then wait 30 seconds and press again)

Prime about 20 seconds. Then as many 10 second cranks as necessary to start with a 20 second pause in between. Mine usually starts the 3rd crank.

This is 1975 technology. In the old days some cars were cranky starting cold as well :)

Does the altitude setting affect starting?