Onan Generator Question

Bobby Fazio · 08-23-2019, 08:51 AM

Hey guys, I have Onan 4000 in my 2003 Winnebago. I am approaching 1,000 hours and I have heard some stories about how difficult and costly they can be to replace. I always make sure the oil is topped off and check air filter but I get nervous about running it too long at a time, especially during the nasty hot weekends like we just had at Atco and Cecil. How many hours has everyone been getting from these generators?

Steve Polhill · 08-23-2019, 09:12 AM

Honestly if it's still running well and you keep up that maintenance you will be fine. There is no set number of hours when they go. It's just like a car. If you maintain it properly it will last a good long time.

Also Onan suggests you "Exercise" your generator for at least an hour. It's not good for them to start and run for 5 minutes and shut off.

ss3011 · 08-23-2019, 09:31 AM

I have a Onan 4000 in my 1996 Southwind Storm . It had a problem a few years ago , where it would run for a few minutes then quit . Needed a new ignition coil / wire assembly . You have to remove the whole generator to be able to replace it . So that is a pain , and apparently that coil is a common problem . Other than that issue , the generator has run well for all these years and is still going strong .

Rich Biebel · 08-23-2019, 10:01 AM

4KY's can last 2000-3000hrs or more if they are taken care of regularly...

Change the oil often is number one....

3 common problems on them....

Starters fail and sometimes lock up the engine making owners think the engine is seized....its the starter drive jamming in the blower wheel. The starter drive is plastic and wears out and breaks.

Newer style coil is a molded one piece magneto style coil. It has a very sharp bend out from under where its mounted. The wire fractures at that bend and the spark grounds out causing unit not to run or start and shut off. It's tricky to diagnose since when you look you might see what you think is a good ignition spark.....Its no good once it tries to fire the spark plug under compression...

Brushes wear out and unit won't run....Might have 600hrs on it or 1600....
I just did one with 600 for a racer.....

All these repairs require the machine to be removed from MH......Not a terribly difficult job but not a walk in the park either.

Older MH's are often way more difficult to remove the generator than newer MH's.....

I have 2 KY's myself.....Great little machines but they have some reliability issues.

I work on Onan's just about everyday during the spring-summer months....

Bobby Fazio · 08-23-2019, 11:14 AM

Quote:

Originally Posted by ss3011

I have a Onan 4000 in my 1996 Southwind Storm . It had a problem a few years ago , where it would run for a few minutes then quit . Needed a new ignition coil / wire assembly . You have to remove the whole generator to be able to replace it . So that is a pain , and apparently that coil is a common problem . Other than that issue , the generator has run well for all these years and is still going strong .

How many hours are on that bad boy?

ss3011 · 08-24-2019, 03:57 PM

My Onan 4000 has 440 hrs . I only use it to run the Microwave , and the TV . Since the TV is old school , don't run the TV anymore .

Bobby Fazio · 08-25-2019, 08:11 AM

Great info Rich. Thank you!

Quote:

Originally Posted by Rich Biebel

4KY's can last 2000-3000hrs or more if they are taken care of regularly...

Change the oil often is number one....

3 common problems on them....

Starters fail and sometimes lock up the engine making owners think the engine is seized....its the starter drive jamming in the blower wheel. The starter drive is plastic and wears out and breaks.

Newer style coil is a molded one piece magneto style coil. It has a very sharp bend out from under where its mounted. The wire fractures at that bend and the spark grounds out causing unit not to run or start and shut off. It's tricky to diagnose since when you look you might see what you think is a good ignition spark.....Its no good once it tries to fire the spark plug under compression...

Brushes wear out and unit won't run....Might have 600hrs on it or 1600....
I just did one with 600 for a racer.....

All these repairs require the machine to be removed from MH......Not a terribly difficult job but not a walk in the park either.

Older MH's are often way more difficult to remove the generator than newer MH's.....

I have 2 KY's myself.....Great little machines but they have some reliability issues.

I work on Onan's just about everyday during the spring-summer months....

08-23-2019, 08:51 AM	#1
Bobby Fazio VIP Member Join Date: Nov 2009 Location: Egg Harbor Township, NJ Posts: 1,377 Likes: 1,145 Liked 3,494 Times in 426 Posts	Onan Generator Question Hey guys, I have Onan 4000 in my 2003 Winnebago. I am approaching 1,000 hours and I have heard some stories about how difficult and costly they can be to replace. I always make sure the oil is topped off and check air filter but I get nervous about running it too long at a time, especially during the nasty hot weekends like we just had at Atco and Cecil. How many hours has everyone been getting from these generators? __________________ '65 Mustang SS/L & L/SA DriverInterviews.com \| App.DragInsights.com

08-23-2019, 09:12 AM	#2
Steve Polhill Senior Member Join Date: May 2003 Location: London Ontario Posts: 515 Likes: 40 Liked 262 Times in 74 Posts	Re: Onan Generator Question Honestly if it's still running well and you keep up that maintenance you will be fine. There is no set number of hours when they go. It's just like a car. If you maintain it properly it will last a good long time. Also Onan suggests you "Exercise" your generator for at least an hour. It's not good for them to start and run for 5 minutes and shut off. __________________ Steve Polhill 3520 STOCK, COMP

08-23-2019, 09:31 AM	#3
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 885 Likes: 63 Liked 221 Times in 102 Posts	Re: Onan Generator Question I have a Onan 4000 in my 1996 Southwind Storm . It had a problem a few years ago , where it would run for a few minutes then quit . Needed a new ignition coil / wire assembly . You have to remove the whole generator to be able to replace it . So that is a pain , and apparently that coil is a common problem . Other than that issue , the generator has run well for all these years and is still going strong .

08-23-2019, 10:01 AM	#4
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,275 Likes: 25 Liked 510 Times in 200 Posts	Re: Onan Generator Question 4KY's can last 2000-3000hrs or more if they are taken care of regularly... Change the oil often is number one.... 3 common problems on them.... Starters fail and sometimes lock up the engine making owners think the engine is seized....its the starter drive jamming in the blower wheel. The starter drive is plastic and wears out and breaks. Newer style coil is a molded one piece magneto style coil. It has a very sharp bend out from under where its mounted. The wire fractures at that bend and the spark grounds out causing unit not to run or start and shut off. It's tricky to diagnose since when you look you might see what you think is a good ignition spark.....Its no good once it tries to fire the spark plug under compression... Brushes wear out and unit won't run....Might have 600hrs on it or 1600.... I just did one with 600 for a racer..... All these repairs require the machine to be removed from MH......Not a terribly difficult job but not a walk in the park either. Older MH's are often way more difficult to remove the generator than newer MH's..... I have 2 KY's myself.....Great little machines but they have some reliability issues. I work on Onan's just about everyday during the spring-summer months.... __________________ Rich Biebel S/C 1479

08-24-2019, 03:57 PM	#6
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 885 Likes: 63 Liked 221 Times in 102 Posts	Re: Onan Generator Question My Onan 4000 has 440 hrs . I only use it to run the Microwave , and the TV . Since the TV is old school , don't run the TV anymore .