Onan 4000KW generator Carb

[Luke D]

Has anyone had luck cleaning the carb on this unit??!? Gen won’t stay running, only fires when sprayed in air cleaner. Fuel supply and spark not the issue. Onan gets 2 to 3 hundred for a replacement. Aftermarket for example Amazon $60. Has anyone used an aftermarket with success or is Onan Replacement the only avenue to go????

[ducksface]

A rebuild kit is maybe 30 bucks, maybe not.
I've had extremely good luck with cheap Amazon carbs.
Don't even bother to disassemble that carb.
Order an aftermarket based on reviews.

https://www.ebay.com/itm/A041D736-Ca...0AAOSwN1JezmAq

As. Low. As. $28.

[Luke D]

Originally Posted by ducksface

A rebuild kit is maybe 30 bucks, maybe not.
I've had extremely good luck with cheap Amazon carbs.
Don't even bother to disassemble that carb.
Order an aftermarket based on reviews.

https://www.ebay.com/itm/A041D736-Ca...0AAOSwN1JezmAq

As. Low. As. $28.

Thanks will do.... Amazon it is. Found kit for 30 bucks getting new carb

Thanks

[LMhawk59]

May not be the carb onan has a built in safety if the regulator has a fault engine will not stay running may only run for 2 seconds then shut down it's the regulator if the onan is run at higher then the governor allows you can burn out the main stator that makes the 120 volts you measure this off the output terminals should only be 60 Hertz

[Luke D]

Originally Posted by LMhawk59

May not be the carb onan has a built in safety if the regulator has a fault engine will not stay running may only run for 2 seconds then shut down it's the regulator if the onan is run at higher then the governor allows you can burn out the main stator that makes the 120 volts you measure this off the output terminals should only be 60 Hertz

Thanks for the information. I have added a new control board. Still have old one. Is regulator part of board or is it elsewhere???
New board didn’t fix issue. Thank you for the input. I have look at wiring, carb solenoid, fuel delivery, spark ......gen has me baffled.. used to run great.

[EA37TS]

Originally Posted by Luke D

Has anyone had luck cleaning the carb on this unit??!? Gen won’t stay running, only fires when sprayed in air cleaner. Fuel supply and spark not the issue. Onan gets 2 to 3 hundred for a replacement. Aftermarket for example Amazon $60. Has anyone used an aftermarket with success or is Onan Replacement the only avenue to go????

Only runs when sprayed in air cleaner and fuel supply not the issue are kind of contradictory. If the fuel supply was not the issue you would not have to spray fuel in through the air cleaner.

You don't mention what type of rig this is open or what year. A few years ago Onan had a bad run on fuel pumps.

[Luke D]

Originally Posted by EA37TS

Only runs when sprayed in air cleaner and fuel supply not the issue are kind of contradictory. If the fuel supply was not the issue you would not have to spray fuel in through the air cleaner.



You don't mention what type of rig this is open or what year. A few years ago Onan had a bad run on fuel pumps.

2015 Thor ACE 30.1 I have check fuel delivery by pulling hose. I get a steady flow and hear pump. Bowl is filling as when you turn bowl drain screw fuel comes out. Thanks for your info. I’ll re try.

[EA37TS]

Originally Posted by Luke D

2015 Thor ACE 30.1 I have check fuel delivery by pulling hose. I get a steady flow and hear pump. Bowl is filling as when you turn bowl drain screw fuel comes out. Thanks for your info. I’ll re try.

2012 to 2015 was the run of bad fuel pumps on Onans. Had one on my SunSeeker. They usually showed up within the first 100 hours of operation.

[Luke D]

Mine has 352 hours on it. According to records keep on this MH, fuel pump was replaced at 88.34 hours. Looks new and clean, did new fuel filter. It’s working but gen only fires and dies. Using spray in carb fires every time. Hate to pull and change carb but everything else has been tried.

Luke

[Luke D]

Originally Posted by Luke D

Has anyone had luck cleaning the carb on this unit??!? Gen won’t stay running, only fires when sprayed in air cleaner. Fuel supply and spark not the issue. Onan gets 2 to 3 hundred for a replacement. Aftermarket for example Amazon $60. Has anyone used an aftermarket with success or is Onan Replacement the only avenue to go????

Update!!!!!

Pulled carb brought home. Opened up and clean as a whistle. No varnish, no gunk. Okay soaked in Sea foam anyways. Figured I’d pull float ..... guess what stuck in closed position. Pulled it blew air through It all other parts of carb. Re soaked. Now back together float working fine. Going to re install tomorrow. Holding off on new one.

[Bob Denman]

Good luck with the re-install.
I think you got it beat!

[ducksface]

Ha!
You're holding off on a purchase and I bought one as a spare because of your story

[Luke D]

Originally Posted by Bob Denman

Good luck with the re-install.

I think you got it beat!

Well Bob , no one can say a Motor home isn’t a lot of work. Thank the Lord I grew up in a family of six kids. Through my dad, I learned, electrical, plumbing, mechanical you name it, building etc. Spent years as a mechanical Engineer for Goulds pump. Then ran a classic car restoration shop. At least I can fix a lot of these things. Poor owners who can’t.
There a lot of fun , a Motorhome, but heck things break just sitting still lol. Love traveling in it.
BTW here’s a stupid move by Thor. The 2021 ACE line still on 19.5 wheels, old chassis and V-10. Need to move up to Hurricane to get new F53 chassis, 22’s tires and new V8. Strange

[Luke D]

Originally Posted by ducksface

Ha!

You're holding off on a purchase and I bought one as a spare because of your story

Nope I bought on Amazon. No more gen less drama

[Pete'sMH]

Originally Posted by Luke D

Well Bob , no one can say a Motor home isn’t a lot of work. Thank the Lord I grew up in a family of six kids. Through my dad, I learned, electrical, plumbing, mechanical you name it, building etc. Spent years as a mechanical Engineer for Goulds pump. Then ran a classic car restoration shop. At least I can fix a lot of these things. Poor owners who can’t.
There a lot of fun , a Motorhome, but heck things break just sitting still lol. Love traveling in it.
BTW here’s a stupid move by Thor. The 2021 ACE line still on 19.5 wheels, old chassis and V-10. Need to move up to Hurricane to get new F53 chassis, 22’s tires and new V8. Strange

Why is that a stupid move by Thor? I’m sure they are just using up the supply of 2020 chassis’s and ACE’s are the entry level coach. What else would they do with them? Can’t just junk ‘em!

[Luke D]

Originally Posted by Pete'sMH

Why is that a stupid move by Thor? I’m sure they are just using up the supply of 2020 chassis’s and ACE’s are the entry level coach. What else would they do with them? Can’t just junk ‘em!

Your point is well taken. I was surprised Thor took this route. There are so many ACEs out there. The thought just seemed odd to me, even though entry level why not upgrade to new chassis and engine. According to Thor there is no future plan to upgrade the ACE line. I looked at a 30.4 and GM told me that THOR is using new F53 chassis and V8 on Hurricane models on up. Most likely a monitory decision. Thanks for the Feedback Pete. Maybe it’s just me but I’ve had great luck with the ACE entry level line. Definitely no engine issues. V-10 fine, other than my 9 mpg. I learned to beef up front and rear suspension so ride is decent. I thought the new F53 chassis was develop for a better load, tow and ride capability. I’m not sure about V8 mpg improvement or reliability.
Happy RVing
Stay safe

Thanks Pete
Luke

[Pete'sMH]

Originally Posted by Luke D

Your point is well taken. I was surprised Thor took this route. There are so many ACEs out there. The thought just seemed odd to me, even though entry level why not upgrade to new chassis and engine. According to Thor there is no future plan to upgrade the ACE line. I looked at a 30.4 and GM told me that THOR is using new F53 chassis and V8 on Hurricane models on up. Most likely a monitory decision. Thanks for the Feedback Pete. Maybe it’s just me but I’ve had great luck with the ACE entry level line. Definitely no engine issues. V-10 fine, other than my 9 mpg. I learned to beef up front and rear suspension so ride is decent. I thought the new F53 chassis was develop for a better load, tow and ride capability. I’m not sure about V8 mpg improvement or reliability.
Happy RVing
Stay safe

Thanks Pete
Luke

Well since Ford stopped making the old chassis/engine I’m sure Thor will switch when they use up to older stock. Unless they are going to discontinue the ACE which seems unlikely. Personally I’m Rey happy with my 2019 F53 coach. It’s a SOB and it seems reasonably quiet and I’m ok with the ride and handling. New ones might be better but I got a great price and I’m pleased with the quality and features.

[Luke D]

Originally Posted by Pete'sMH

Well since Ford stopped making the old chassis/engine I’m sure Thor will switch when they use up to older stock. Unless they are going to discontinue the ACE which seems unlikely. Personally I’m Rey happy with my 2019 F53 coach. It’s a SOB and it seems reasonably quiet and I’m ok with the ride and handling. New ones might be better but I got a great price and I’m pleased with the quality and features.

Well said, if happy that’s all that matters. I am pleased with my 30.1 with the F53 ride too. I was in contact with Thor on the new 30.4. They are the ones that told me of no plans to change over the new ACE line. Was thinking of upgrading next year. New instead of used. I even have been looking at Diesel pushers. Doesn’t seem you can justify them after the cost. Going cross country again next Summer. Who knows present coach may do it again.

[Beau388]

Originally Posted by Luke D

Well Bob , no one can say a Motor home isn’t a lot of work. Thank the Lord I grew up in a family of six kids. Through my dad, I learned, electrical, plumbing, mechanical you name it, building etc. Spent years as a mechanical Engineer for Goulds pump. Then ran a classic car restoration shop. At least I can fix a lot of these things. Poor owners who can’t.
There a lot of fun , a Motorhome, but heck things break just sitting still lol. Love traveling in it.
BTW here’s a stupid move by Thor. The 2021 ACE line still on 19.5 wheels, old chassis and V-10. Need to move up to Hurricane to get new F53 chassis, 22’s tires and new V8. Strange

Plant 750 shut down because of Indiana Governor's edict. MorRyde had modified 100+ chassis V-10 for ACE production in March, April and May. This because the new V-8 chassis required engineering changes which require Ford's approval before MorRyde could modify the new chassis. This was a decision made in October 2019. When limited production was restarted, only ACEs and Freedom Travelers were produced on old chassis until Ford gave approval for MorRyde modifications. This was not done until the middle of June, so no new chassis into Plant 750 until July after approximately 120 ACEs and Freedom Travelers had been completed.
All plant 750 coaches have always been on 19.5" wheels as no coach was heavy enough to use 22.5" wheels. With the 34 and 35 coaches maxing out the capability of 245/70-19.5 tires, the engineering decision was to move to 22.5" wheels on the 22,000 lb chassis. All new chassis used by plant 750 that are rated less then 22,000 lbs will continue to have 19.5" wheels.
I might explain that 70% of the total production of Plant 750 are ACE and Freedom Traveler. Since plant 750 uses batch production, there is only one week every other a month where Hurricanes and Windsports are produced.

[Luke D]

Originally Posted by Beau388

Plant 750 shut down because of Indiana Governor's edict. MorRyde had modified 100+ chassis V-10 for ACE production in March, April and May. This because the new V-8 chassis required engineering changes which require Ford's approval before MorRyde could modify the new chassis. This was a decision made in October 2019. When limited production was restarted, only ACEs and Freedom Travelers were produced on old chassis until Ford gave approval for MorRyde modifications. This was not done until the middle of June, so no new chassis into Plant 750 until July after approximately 120 ACEs and Freedom Travelers had been completed.
All plant 750 coaches have always been on 19.5" wheels as no coach was heavy enough to use 22.5" wheels. With the 34 and 35 coaches maxing out the capability of 245/70-19.5 tires, the engineering decision was to move to 22.5" wheels on the 22,000 lb chassis. All new chassis used by plant 750 that are rated less then 22,000 lbs will continue to have 19.5" wheels.
I might explain that 70% of the total production of Plant 750 are ACE and Freedom Traveler. Since plant 750 uses batch production, there is only one week every other a month where Hurricanes and Windsports are produced.

Great info. Knew there had to be a reason. Guess the Thor people I talked to had no insight to what you know. That’s why this site is so great. Very nice explanation.

Thank you
Stay safe