Onan 4000 Generator shuts down

[coberly]

On our 2017 Jayco Alante the generator shuts down when the outside temperature and/or tire temperature gets hot. The Jayco rep said the problem was that the for cooling the generator pulls air from under the coach and just behind the left front tire. He suggested the modification shown in the attachment as a solution. However, this part/modification is no longer available from Jayco.

Does anyone have any experience with this modification and did it solve the problem.? I'd oike to know before I cut a hole in the door to do something similiar.

Thanks

 

[Mike-NM]

Ton of info on this issue.... take your pick. I fixed mine by moving the idle arm notch to the left one spot then placed it back in higher altitudes.. Others had low oil or high levels of oil, others had vents cut, others state the carb bowl spills out, others say the fuel filter and or fuel pump. never ending story.....

https://www.jaycoowners.com/forums/search.php?searchid=7058536

 

[foretm]

He suggested the modification shown in the attachment as a solution. However, this part/modification is no longer available from Jayco.

I don't see anything attached, but agree with Mike, the "solution" is different for each person. Mine did this back when I got it and took it to Cummins and they redid the exhaust and some other work and said it resolved it. So far so good but haven't had it out on a really hot day yet. I'm looking to add an additional vent to my generator door, but i've already dealt with the oil overfill issue.

 

[coberly]

Jayco solution

I appreciate the responses and apologize for the lack of attachment.
I'll try again.

 

[foretm]

I'm considering something similar to this on mine... I have a different type door, that swings out vs up, but same basic premise... I plan to do it if the situation continues, but right now it seems to be doing ok.

 

[Esqui]

I have a 2021 Jayco Alante 29F that had the same issue. I took mine directly to Onan. They are telling me that because the generator is located towards the front (behind the driver side front tire), it is sucking up all the hot air from the engine and tires. This is causing it to overheat the gas in the carburetor, causing it to evaporate, which then causes the generator to shut down. They claim to have a fix for it. They are going to replace the carburetor with a newly redesigned carburetor and add some extra insulation lining.

I am new to all this and not mechanically inclined at all. Does this make sense to any of you?

I'm supposed to pick up the RV sometime next week. Stay tuned...

 

[parrott]

I have a 2021 Jayco Alante 29F that had the same issue. I took mine directly to Onan. They are telling me that because the generator is located towards the front (behind the driver side front tire), it is sucking up all the hot air from the engine and tires. This is causing it to overheat the gas in the carburetor, causing it to evaporate, which then causes the generator to shut down. They claim to have a fix for it. They are going to replace the carburetor with a newly redesigned carburetor and add some extra insulation lining.

I am new to all this and not mechanically inclined at all. Does this make sense to any of you?

I'm supposed to pick up the RV sometime next week. Stay tuned...

A new designed carb would be great. Can you get them to give you a part number for the carb?

 

[Esqui]

Will do...I will ask for the part number when I pick it up.

 

[foretm]

A new designed carb would be great. Can you get them to give you a part number for the carb?

X2!!!

 

[Esqui]

So...the part number for the "newly redesigned" carburetor is A042P619. So far, I have had no issue while running the generator. I do have a caveat to that, it has been very cool weather so maybe, it just hasn't overheated yet? I will update this post as soon as there is an update.

 

[Esqui]

So...the part number for the "newly redesigned" carburetor is A042P619. So far, I have had no issue while running the generator. I do have a caveat to that, it has been very cool weather so maybe, it just hasn't overheated yet? I will update this post as soon as there is an update.

So...the carburetor swap did not work. I Spoke with Jayco and it looks like the solution is adding that louver or vent with a thick enough gasket to butt up against the air intake of the generator. I'm supposed to be taking it to La Mesa RV next week for this work. I would do it, but I'm afraid that if I do it, and something goes wrong with the generator, they will blame it on me and void the warranty.

 

[Ryan B-JAY]

I also have a 2021 Alante 29F. Is the vent and gasket something that Jayco is covering under warranty?

 

[foretm]

I highly doubt it, but if it helps, I recently ordered the parts shown in post #4 above from my local camping world and they did not need a VIN number to do it. I simply told them it was for a Forest River FR3 and it was a generic part. The prices are below, i'll reply here when they arrive and when i get them put in.



70A09401A (grille) - $58

[FONT=&quot]70A09400A (airbox) - $18[/FONT]

 

[Ovalvw]

I’ve fixed this problem for a friend recently.
The selonoid on bottom carb was not working
We replaced that and also removed float bowl
Pull the altitude adjustment cap off turn this screw
in all the way counting the turns then remove it and
Also remove the drain screw it was plugged In the bowl
Clean Everything well including the ports in the bowl
Reassemble turning the altitude adjustment screw to the same
Position as it was but open to another half turn to turn out
This should smooth it out. We adjusted his while running It’s
Runs very nice now
All our best central Florida

 

[foretm]

I recently ordered the parts shown in post #4 above from my local camping world and they did not need a VIN number to do it. I simply told them it was for a Forest River FR3 and it was a generic part. The prices are below, i'll reply here when they arrive and when i get them put in.

70A09401A (grille) - $58
[FONT=&quot]70A09400A (airbox) - $18[/FONT]

Here they are installed. Since the Onan 4000 is tapered being wider at the bottom than the top, the sides and bottom of the back piece had to be trimmed about 1/2" at the bottom tapering up to 0" at the top. Easy to do with a razorknife, just score and bend. The door was removed and a jigsaw was used to cut the opening. The door is styrofoam on the inside, so I used oversize fender washers on the back of the stainless bolts and nylon nuts. I painted mine white to match the coach, be sure to use a paint/primer combo or prime it first.

I can tell you that the air moving through that opening is significant, and in my case since the generator is right behind the engine, I think its sucking too much hot air and overheating. This should resolve the issue I have which is it shutting down while stationary and both engine and generator running at the same time. Won't know for sure until it gets much hotter, but will update when we get some hot weather.

 

[Esqui]

Here they are installed. Since the Onan 4000 is tapered being wider at the bottom than the top, the sides and bottom of the back piece had to be trimmed about 1/2" at the bottom tapering up to 0" at the top. Easy to do with a razorknife, just score and bend. The door was removed and a jigsaw was used to cut the opening. The door is styrofoam on the inside, so I used oversize fender washers on the back of the stainless bolts and nylon nuts. I painted mine white to match the coach, be sure to use a paint/primer combo or prime it first.

I can tell you that the air moving through that opening is significant, and in my case since the generator is right behind the engine, I think its sucking too much hot air and overheating. This should resolve the issue I have which is it shutting down while stationary and both engine and generator running at the same time. Won't know for sure until it gets much hotter, but will update when we get some hot weather.

That looks amazing! Thanks for sharing. If possible, can you please share the links for the materials you used? My RV is currently at La Mesa RV in Port St. Lucie, Florida and they are trying to source out the materials for the fix. Thank you in advance.

 

[foretm]

Sure thing.... The top two parts below will need to be ordered by an RV dealer. These are Forest River FR3 part numbers, but you do not need a VIN number to order. My local Camping World ordered it for me through the OEM parts counter, all in ~$95. Not cheap I know...



70A09401A (grille) - $58
[FONT=&quot]70A09400A (airbox) - $18[/FONT]
[FONT=&quot]6 - 1 1/2" 10-24 Stainless Steel Screws[/FONT]
[FONT=&quot]6 - Stainless Fender Washers[/FONT]
[FONT=&quot]6 - 10-24 Nylon Lock nuts[/FONT]
[FONT=&quot]1 - 5' section of 1/2" pipe insulation[/FONT]
[FONT=&quot]1 - can of Spray Adhesive[/FONT]
[FONT=&quot]1 - can of white primer/enamel paint
[/FONT]

 

[Esqui]

Sure thing.... The top two parts below will need to be ordered by an RV dealer. These are Forest River FR3 part numbers, but you do not need a VIN number to order. My local Camping World ordered it for me through the OEM parts counter, all in ~$95. Not cheap I know...



70A09401A (grille) - $58
[FONT=&quot]70A09400A (airbox) - $18[/FONT]
[FONT=&quot]6 - 1 1/2" 10-24 Stainless Steel Screws[/FONT]
[FONT=&quot]6 - Stainless Fender Washers[/FONT]
[FONT=&quot]6 - 10-24 Nylon Lock nuts[/FONT]
[FONT=&quot]1 - 5' section of 1/2" pipe insulation[/FONT]
[FONT=&quot]1 - can of Spray Adhesive[/FONT]
[FONT=&quot]1 - can of white primer/enamel paint
[/FONT]

Thank you so much! I really appreciate you taking the time to make the list. I will be contacting La Mesa RV this morning.

 

[BoG-JAY]

Anyone have luck ordering those parts for an fr3 lately?

I am getting blank stares and demands for vin numbers

 

[jimmoore13]

The recommendations for improving cooling to the generator are terrific.

FWIW, this might be the problem. Vapor Lock.
Just a guess, but that might explain what's happening.

As far as I know, vapor lock is largely related to carburetted engines. While there is a fuel pump that moves fuel from the tank into the float bowl, it's not a high pressure pump. With fuel injection, the pump generates substantially higher pressure...and it MIGHT overcome any tendencies for vapor lock. That's mostly a hunch, and there are many variables to consider.

Anyway, cooling the generator engine bay is likely to resolve vapor lock.