RV.Net Open Roads Forum: Tech Issues: Generac 36LP-Inverter issue

RV Blog

  |  

RV Sales

  |  

Campgrounds

  |  

RV Parks

  |  

RV Club

  |  

RV Buyers Guide

  |  

Roadside Assistance

  |  

Extended Service Plan

  |  

RV Travel Assistance

  |  

RV Credit Card

  |  

RV Loans

Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Generac 36LP-Inverter issue

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 
Sponsored By:
pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 07/11/11 01:54pm Link  |  Print  |  Notify Moderator

I have a 2002 version of the above generator.

It's a little bit hard starting............maybe 6-8 seconds. But when it does start, it purrs.

UNTIL I put any kind of substantial load on it, like the A/C or the microvwave. Then it underrevs badly like it's being starved and the voltage drops into the 90s. If I turn off the load, it continues to act like it's starved for a few minutes when it seems to recover. Or, if I shut it off immediately and restart, it idles just fine.

I've checked the air filter; even run it w/o the filter on, altogether. No change.

I can hear the solenoid fuel cutoff switch opening when I first hold the start switch down.

Oil level is fine. Only has 10 hours on the generator.

I'm beginning to suspect either my primary LP regulator at the tanks or the secondary regulator at the generator itself. Is there any way to test them besides looking for blue flames at the range or the fridge?

Any other things to check?

MrWizard

Traveling

Moderator

Joined: 06/27/2004

View Profile



Posted: 07/11/11 02:40pm Link  |  Print  |  Notify Moderator

10 hours, 9yrs old!

SHEESH even LP generators need to be exercised to keep the internal parts well lubed

Run it for 10 hours then change the oil

You still might have to replace the regulators but I would run it first


Radiate The Happy
....

Connected using Verizon and AT&T
1997 F53 Bounder 36s


pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 07/11/11 02:52pm Link  |  Print  |  Notify Moderator

Did I mention it was two weeks new to me? The original owner was just an RV park kinda guy, I guess. I'll change the oil.

NRALIFR

Truck Camping Out West

Senior Member

Joined: 11/27/2005

View Profile



Posted: 07/12/11 01:27pm Link  |  Print  |  Notify Moderator

I've got the same unit in my truck camper, and I was also having trouble starting it at one time. It started out sorta like yours, with a longer than normal crank time and progressively got worse over the course of a year or so. It finally got to where I was having to work pretty hard to get it started. Long story short, that item you're calling a "secondary regulator" was causing the problem.

That device, which is present on all LP powered engines I've seen, is called a "zero governor" by the manufacturer. It doesn't regulate the LP pressure the way the one on your tanks does. It's really more of an on/off valve that's actuated by the vacuum present in the intake manifold of the engine when its either cranking or running. It's very sensitive to vacuum, and when it's working properly the slightest vacuum in the manifold will cause it to open.

As they age, they tend to stick closed, and it will start taking more and more vacuum to open them. That's when the crank time starts getting longer. Additionally, I think yours may be exhibiting an additional problem: not opening fully. Maybe because the valve mechanism is stiff or corroded due to the extremely low number of hours on the unit, or maybe the diaphragm inside the valve has a hole in it. I think this could be what is making you think the engine is starving for fuel.

If you want to rule out an LP supply problem from the tanks, do this: start the generator, but don't put any heavy AC loads on it. With the generator idling with no load, turn on every other LP appliance in the RV. Fridge, stove burners, oven, furnace. If there's an LP supply problem, I would think the generator would start to stumble with all of those other LP appliances burning (especially the furnace).

If the generator continues to purr along normally, Your LP regulator at the tanks is probably OK.

The valve on your generator is probably a Garretson/IMPCO type KN regulator (zero governor), and it's a relatively inexpensive unit (about $50) if you DON'T buy it from Generac. I've seen some Generac parts dealers charging as much as $250 for one! Plus, you can buy a much better unit from US Carburetion in West Virginia. It's better because it has a manual primer button on it that can be used to either prime the generator, or to simply exercise the internal valve opened and closed if you think it's sticking. It isn't possible to really prime your generator with the valve you have now, despite the fact that your panel may have a "Prime" switch on it. All the PRIME switch does is open the Fuel Lockoff Solenoid, but the LP can't get past the KN regulator because it's closed! With the new KN regulator, push the PRIME switch on the panel, then use the manual prime button on the regulator to give it a couple of 1-2 second shots, and it's primed!

See this thread, and and this one for more discussion in the Truck Camper forum about this generator.

[emoticon][emoticon]


2001 Lance 1121 on a 2016 F450


pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 07/12/11 06:08pm Link  |  Print  |  Notify Moderator

Reading these threads has been an immense help, NRALIFR. For knowledge and, hopefully, for application.

As I live in Mexico, getting parts quickly is not easy. I have a replacement primary regulator coming down tomorrow. As I have had these fail before on two other RVs, I figured I would start here. If my current one is good, a backup one in Mexico is not a bad thing.

Part of the incredible irony of living in Mexico is the fact that SO MANY ITEMS are grown, built or assembled down here but are actually difficult and expensive to get. Yet they are probably flying by me in a semi as they head to market in the States.

But I suspect the problem is the current Garretson model I have on it.

Now, since you have replaced yours, I have to ask; how did you get the old one off the engine itself? Do you have to remove that whole assembly, including the solenoid fuel cutoff as well as the bracket that the cutoff and the regulator are mounted to? Can you give some advice?

I suspect I will be removing it on the road, as we leave in two weeks for TWO MONTHS. And as we love dry camping and will be in hot climes for the first month, the generator and a/c are essential.

NRALIFR

Truck Camping Out West

Senior Member

Joined: 11/27/2005

View Profile



Posted: 07/12/11 08:19pm Link  |  Print  |  Notify Moderator

I didn't have to remove the whole generator, but it was pretty tight getting it replaced. I did have to remove the whole assembly (bracket/solenoid/regulator). If I remember correctly, there is one bolt on the right side that supports the bracket that was the hardest to get to. If your arms aren't skinny and nimble, you might have to remove the generator. My generator installation looks exactly like the picture posted by "sleepy" in the first thread link. Not much clearance on the right-hand side. Once it's off, you'll need a couple of good sized pipe wrenches to get things apart and back together.

Also, if you're planning on putting a lot of hours on the generator running the A/C, you'll need to have good access to LP refill stations. I understand they tend to burn through the fuel pretty fast when they have that kind of load for long periods. Once you get it running, you might want to run the A/C with it for several hours at home to get an idea of the fuel consumption. Weigh your tank before and after your test to get lbs/hour fuel usage. I've only run mine for an hour or two at a time max, and only when we need its higher output for running the microwave or occasionally the A/C during the day. Typical usage for us is to have it running for 15-20 minutes to cook a meal, then it's off. The rest of the time, I use a Yamaha 1000 and forgo the A/C altogether.

[emoticon][emoticon]

pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 07/12/11 08:55pm Link  |  Print  |  Notify Moderator

We really just use it to cool down the TC after coming off the road or a quick cooldown just for bed. If it's so hot that it needs to be run 24/7, we move or we bite the bullet and get on the grid, somewhere.

The Generac literature says it burns about .41 gallons per hour at half load. The A/C unit is probably a bit over half load so a half gallon an hour is probably close. I now see why people are carrying a more efficient gas genny with them sometimes.

Yeah, I can see the bolt on the passenger side you are talking about. Looks like end wrench only area.

Thanks for the quick comeback.

pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 07/27/11 08:31am Link  |  Print  |  Notify Moderator

Well, NRALIFR, your advice was on the money. I finished replacing my old zero governor with a new one from the source you recommended, US Carbueration, and it is running perfectly.

YES, it was a bear to remove the old governor from the series of threaded elbows that Generac uses.

I ended up not having to remove the bracket that the solenoid and governor were attached to. I removed the U-bolt near the solenoid and the mounting bolts that thread into the bottom of the governor and just removed the assembly itself. There was one middle bolt on the bracket that had no clearance to get at the head as a generator mounting bolt (which was put in AFTER the bracket bolt) was in the way. So, I loosened the other two and this allowed me to "rock" the bracket up and down and gave me clearance to remove the governor mounting bolts.

Thanks again, amigo. You save me the repair bill AND you saved me big time on the US Carb tip. My first Google search was showing governors for 150.00 and more. But I was searching under "Generac repair parts" and only voracious RV middlemen were coming up.

NRALIFR

Truck Camping Out West

Senior Member

Joined: 11/27/2005

View Profile



Posted: 08/04/11 04:58am Link  |  Print  |  Notify Moderator

Just saw this today, thanks posting the outcome for us. Work has kept me from looking at this site much lately.

Your method of removing that one bolt reminded me of how I got mine out. Pretty much the same way you did!

Glad to hear that it all worked out for you, and that the generator is running fine now. I often wonder how much this one part (the KN regulator) has contributed to the "less than stellar" reputation of this particular generator. There are a fair number of 36LP owners on the truck camper forum, and starting difficulties seem to be the most common complaints.

Hope it's not as hot where you are now as it is here. Yesterdays high in Little Rock was 114!

[emoticon][emoticon]

* This post was edited 08/04/11 05:37am by NRALIFR *

pezvela

San Carlos, Sonora, Mexico

Senior Member

Joined: 08/21/2007

View Profile


Offline
Posted: 08/04/11 08:20am Link  |  Print  |  Notify Moderator

Concur completely on this governor being the likely culprit in many cases for Generac's bad reputation. They DO recommend exercising the genner for a half hour a week! I'll bet 90% of owners arent doing that. I doubt I'll remember w/o a pop up reminder in my main program.

But it is still a thirsty and loud generator. I probably would remove it just carry my Yammy 2800i but the Generac is sure convenient. One button, rain or shine.

This Topic Is Closed  |  Print Topic  |  Post New Topic  | 

Open Roads Forum  >  Tech Issues

 > Generac 36LP-Inverter issue
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:

© 2019 CWI, Inc. © 2019 Good Sam Enterprises, LLC. All Rights Reserved. | Terms of Use | PRIVACY POLICY | YOUR PRIVACY RIGHTS