Onan 4KW Gen set not starting

jazzerjump · 02-28-2014, 01:36 PM

We purchased a 2004 Sightseer with the 4kW Onan generator in Oct. I had listed generator problems in the purchase order and while it took awhile eventually the carb got replaced so the unit would run without loading up and dying. Fuel and air filters also replaced.

We left for our first snowbird trip after Christmas and spent two months in the Arizona desert mostly dry camping. The generator ran flawlessly-put about 120 hrs. on it. On the way home we used it one morning prior to pulling out. We stopped at noon to eat and when I tried to start it, nothing. It makes a clicking noise like the solenoid is possibly activating but the started doesn't turn over-just hear a slight buzzing noise then get the low cranking rpm code. Any thoughts from anyone? Not sure how to trouble shoot from here. The trip was a ball and we enjoyed every minute and coach worked great except for the hiccup coming home.

al2ride · 02-28-2014, 01:40 PM

Signs of weak battery or bad starter solenoid. Check voltage on batteries and if good try hitting the starter while trying to start it. Check all connections too.

forest · 02-28-2014, 02:03 PM

Try reaching in to the generator and turning the flywheel manually. The get you hand out of there nad try starting again. Have seen where starter jammed, and this fixed it.

Jbmsr · 02-28-2014, 02:56 PM

Quote:

Originally Posted by jazzerjump

We purchased a 2004 Sightseer with the 4kW Onan generator in Oct. I had listed generator problems in the purchase order and while it took awhile eventually the carb got replaced so the unit would run without loading up and dying. Fuel and air filters also replaced.

We left for our first snowbird trip after Christmas and spent two months in the Arizona desert mostly dry camping. The generator ran flawlessly-put about 120 hrs. on it. On the way home we used it one morning prior to pulling out. We stopped at noon to eat and when I tried to start it, nothing. It makes a clicking noise like the solenoid is possibly activating but the started doesn't turn over-just hear a slight buzzing noise then get the low cranking rpm code. Any thoughts from anyone? Not sure how to trouble shoot from here. The trip was a ball and we enjoyed every minute and coach worked great except for the hiccup coming home.

Check your battery terminals. I believe the generator uses the house battery's to start. How many volts are you showing?
Jesse

Poppab · 02-28-2014, 04:02 PM

Agree with the comments. Be careful reaching in to move flywheel. My only failure to start our Onan was a simple solution...I had inadvertently turned off my Aux Battery switch. Good luck.

CJBROWN · 02-28-2014, 04:45 PM

Does sound like a loose starter cable, so all you're getting is the solenoid click. I have a 4KW microlite, love it. Uses very little fuel, is quiet, and plenty of power for our smaller coach with 1 large air unit.

Just ordered out a IOTA 45ah converter with the smart charger unit to better charge the golf cart house batteries.

camper33 · 02-28-2014, 06:47 PM

I don't know what model of onan you have but the smaller one,
the KY series had issues with the ground terminal. Make sure the connection on the generator is clean and tight. I would try a jumper cable from the engine of the geny to a good chassis ground on the frame of the coach.

George Schweikle · 03-01-2014, 02:38 PM

X2. I paid $70 for a tech at a Cummins-Onan service center show me how to do this. He also said there is a 9/16 hex on the end of the shaft if it can't be turned by hand.

Quote:

Originally Posted by forest

Try reaching in to the generator and turning the flywheel manually. Then get you hand out of there and try starting again. Have seen where starter jammed, and this fixed it.

jazzerjump · 03-01-2014, 07:54 PM

Thanks to all. As soon as the weather changes for the better-we obviously got back to early, 5 degrees tonight and 3-9" of snow expected through tomorrow here in north Idaho-I will try some of these tricks. The connections seemed tight but will clean all and retighten. I did take the solenoid off and clean the connections but not the ground wire. The voltage was in the 13+ range when I checked. The converter was replaced with a three stage charging 45 amp prior to my purchasing the coach. Don't recall the brand off hand but it seemed to keep the coach batteries well charged the whole trip.

allegro1x · 03-08-2014, 03:00 PM

Probably not your problem, but if you have added oil to the gen, they are sensative to over filling. Also, try to use additive to remove ethanol in gas tank. Dave

CJBROWN · 03-08-2014, 04:01 PM

They are also very sensitive to low oil and will not start if that sensor trips. I dinked around with one for quite awhile for a RV buddy, checking fuel, pump, all kinds of stuff. Oil leve was a bit low, topped it up and it started right up and ran fine.

jazzerjump · 03-08-2014, 06:01 PM

Well I was able to work on gen today and try some of these suggestions. Disconnected and cleaned all terminal-batteries and connections at the gen. This is the Onan KY 4 KW, single cylinder model and the ground at the generator is connected directly to the frame-cleaned that connection also.

I then tried to find the starter/flywheel and no luck. The only access panel doesn't give enough access to the unit. I unscrewed the cover but the unit is installed with a rigid mount-doesn't slide out- and there wasn't enough room to remove the cover for better access. Could not see or feel anything-any ideas on where they may be located-fore or aft? It obviously must be near the back of the unit. I would guess getting the unit out is at least a two person job.

Tried starting and same thing-a click and then a humming/buzzing noise but did not turn over. Checked battery voltage at generator connection and was a little low-a little over 13 as it has sat for awhile now-so started coach and tried with the 14.6V at the gen-same result.

I had checked oil when it wouldn't turn over and that was fine. The selling dealer had said they changed the oil and when I checked before when it wouldn't start prior to the carb change out it flowed out of the dipstick hole so I drained and changed it along with the fuel filter-no oil filter on this unit. We put over a 100 hrs. on it during the trip as we did a lot of dry camping and never missed a beat until the next to last night coming home. I also had put stabilizer and fuel cleaner into the tank after the carb change out got the unit running again and ran the unit quite a bit before the trip to clean that system. Guess I may be stuck going back to the local dealer that repaired the gen after the selling dealer didn't-at least the carb replace was free.

rvarner · 03-08-2014, 06:13 PM

Quote:

Originally Posted by jazzerjump

Well I was able to work on gen today and try some of these suggestions. Disconnected and cleaned all terminal-batteries and connections at the gen. This is the Onan KY 4 KW, single cylinder model and the ground at the generator is connected directly to the frame-cleaned that connection also.

I then tried to find the starter/flywheel and no luck. The only access panel doesn't give enough access to the unit. I unscrewed the cover but the unit is installed with a rigid mount-doesn't slide out- and there wasn't enough room to remove the cover for better access. Could not see or feel anything-any ideas on where they may be located-fore or aft? It obviously must be near the back of the unit. I would guess getting the unit out is at least a two person job.

Tried starting and same thing-a click and then a humming/buzzing noise but did not turn over. Checked battery voltage at generator connection and was a little low-a little over 13 as it has sat for awhile now-so started coach and tried with the 14.6V at the gen-same result.

I had checked oil when it wouldn't turn over and that was fine. The selling dealer had said they changed the oil and when I checked before when it wouldn't start prior to the carb change out it flowed out of the dipstick hole so I drained and changed it along with the fuel filter-no oil filter on this unit. We put over a 100 hrs. on it during the trip as we did a lot of dry camping and never missed a beat until the next to last night coming home. I also had put stabilizer and fuel cleaner into the tank after the carb change out got the unit running again and ran the unit quite a bit before the trip to clean that system. Guess I may be stuck going back to the local dealer that repaired the gen after the selling dealer didn't-at least the carb replace was free.

If you have long enough jumper cables or can remove one of the batteries and get close to the generator, try starting it directly on the starter positive terminal-with negative terminal to the frame of course. If it turns over, it's probably a bad solenoid. If not, probably the starter. Good luck.

Richard

camper33 · 03-08-2014, 08:37 PM

If you reach in on the side where the starter solenoid is, you can get your hand into the flywheel and turn the geny over by hand. There is usually a foam piece you have to get your hand in behind. If it is a bad starter you have to remove the top cover to get to the starter as it is on the back side of the geny. The starter and flywheel is on the generator end of the unit (left side). Also when you check for battery voltage at the generator, put the negative on the engine of the generator and the positive on the battery lead at the starter.

jazzerjump · 03-08-2014, 10:43 PM

Thanks all-if it doesn't rain all day tomorrow will have to try reaching in on that side and also try the jump

jazzerjump · 03-12-2014, 03:54 PM

Once again thanks to all who responded. I disconnected the starter side cable from the solenoid and used a jumper battery but again just the humming noise. I then looked and found the fan that obviously is attached to the fly wheel, got a socket on it and with the help of a breaker bar the engine turned. At first I thought the socket just slipped as it was a real tight fit for the socket and wrench but I discovered I could then rotate by hand. Hooked up the jumper and the genny turned over. I hooked the starter wire back to the solenoid and then tried starting to see if it maybe was the solenoid but it did start. When I shut it down after a while it did restart from inside the coach also. Interesting-I suppose the engine could have stopped right at top dead or bottom dead center making it hard to turn over but any thoughts on what may have caused that condition? Apparently the tech George worked with has seen it before but new to me with small motors.

It has been said many times that this forum has helped many RVers, especially newbies and I agree-thank you all a bunch

Jbmsr · 03-12-2014, 10:48 PM

Quote:

Originally Posted by jazzerjump

Once again thanks to all who responded. I disconnected the starter side cable from the solenoid and used a jumper battery but again just the humming noise. I then looked and found the fan that obviously is attached to the fly wheel, got a socket on it and with the help of a breaker bar the engine turned. At first I thought the socket just slipped as it was a real tight fit for the socket and wrench but I discovered I could then rotate by hand. Hooked up the jumper and the genny turned over. I hooked the starter wire back to the solenoid and then tried starting to see if it maybe was the solenoid but it did start. When I shut it down after a while it did restart from inside the coach also. Interesting-I suppose the engine could have stopped right at top dead or bottom dead center making it hard to turn over but any thoughts on what may have caused that condition? Apparently the tech George worked with has seen it before but new to me with small motors.

It has been said many times that this forum has helped many RVers, especially newbies and I agree-thank you all a bunch

Thanks for the update.

We were in 27 degree weather and woke up to no hot water or flow. Posted on irv2 and within minutes I had the part # and the instructions for repair. One hour and WD was happy.

Priceless!

Jesse