Dave_eng
I hope creating a new and expanded post for this problem is not violating some forum rule.

Two weeks ago I posted:
Quote:
I have a 20 KW air cooled unit bought Nov 13 2009.
model 0055251
serial 5655406

This week for the first time it failed to exercise properly. Over crank error.
Battery and charger OK as was fuse. In manual mode it would turn over but not start.

Removed the air filter and found choke plate open. Closed choke manually and unit started immediately.

I read trouble shooting manual and note that the choke is to cycle open periodically during starting. What is not clear is should choke plate be closed before a start cycle initiates?

I am in a cold snowy area. Is there a history of chokes freezing open?

Any suggestions to avoid this in the future?
Would spraying choke with silicone be worth while?

A comment from d11gnccer:
Quote:
Choke should be closed at the start of a cycle. It is powered open with the solenoid.
The problem has occurred again ( no start, choke open) prompting me to call my dealer as the unit is still under warranty. He is an hour away so is reluctant to come if I can do something. He wants me to bend the choke plate to prevent it from hanging up.

My reluctance to follow his directions comes from the fact that I am not convinced he really understand the choke and how it functions.

My dealer/salesman/ owner's son says all the units he sees (which happens when he switches them from natural gas to propane when they are inside his heated warehouse) the choke plate is open. I don't believe he has any field experience!

My question to forum members is as follows: Does the ambient temp make a difference as to the initial status of the choke plate? i.e. In the summer does the unit still try to start with the choke closed.

A further thought..... does it make a difference if the generator is not connected to a battery as far as the initial position of the choke is concerned?

I am trying to figure out why this guy seems to have his facts screwed up!

I would like to fully understand how the choke functions under all conditions before I challenge the dealer.

Thanks for any help.

Dave p
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Gman1
Just speculation here so take it for what its worth...

The Choke plate on these engines is not a choke in the gasoline fueled sense that we are all accustomed to. It probably does richen the mixture slightly although its main objective is to create (or insure) enough vacuum to open the demand regulator.

If generac would remove that POS and return to the old internal reg with a reliable electric fuel shut off, I would be like the maytag repairman. I guess they are doing it to meet some EPA mandate and are probably not really to blame.
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ceb58
Dave_eng;8158 wrote:
I hope creating a new and expanded post for this problem is not violating some forum rule.

Two weeks ago I posted:
A comment from d11gnccer: The problem has occurred again ( no start, choke open) prompting me to call my dealer as the unit is still under warranty. He is an hour away so is reluctant to come if I can do something. He wants me to bend the choke plate to prevent it from hanging up.

My reluctance to follow his directions comes from the fact that I am not convinced he really understand the choke and how it functions.

My dealer/salesman/ owner's son says all the units he sees (which happens when he switches them from natural gas to propane when they are inside his heated warehouse) the choke plate is open. I don't believe he has any field experience!

My question to forum members is as follows: Does the ambient temp make a difference as to the initial status of the choke plate? i.e. In the summer does the unit still try to start with the choke closed.

A further thought..... does it make a difference if the generator is not connected to a battery as far as the initial position of the choke is concerned?

I am trying to figure out why this guy seems to have his facts screwed up!

I would like to fully understand how the choke functions under all conditions before I challenge the dealer.

Thanks for any help.

Dave p


Gman1;8159 wrote:
Just speculation here so take it for what its worth...

The Choke plate on these engines is not a choke in the gasoline fueled sense that we are all accustomed to. It probably does richen the mixture slightly although its main objective is to create (or insure) enough vacuum to open the demand regulator.

If generac would remove that POS and return to the old internal reg with a reliable electric fuel shut off, I would be like the maytag repairman. I guess they are doing it to meet some EPA mandate and are probably not really to blame.


Agreeing with Gman. It is not per say a choke. The old automatic chokes on gas engines had a thermal spring in them. When it was cold the spring would draw the butterfly closed and as the engine warmed it opened. I think one reason they went to this crap was generators exploding due to the valves leaking.
I have a 35kw LC unit that gave problems like this and this is what I observed and did to fix the unit.

When sitting the butterfly was in the open position, as the unit was turning over the stepper motor would open and close the butterfly. Some times it would go into the third crank cycle before it would start. Then after it started you could turn unit off and re-crank and it would fire right up.
The conclusion was during its off time the LP vapor would dissipate from the line and carb. The demand regulator has a "flap" in it that will only open under vacuum from the engine to allow the fuel in the lines. In its first cold crank cycle the engine was not getting fuel. I adjusted the secondary reg. to max. water column for that unit. I also installed hotter firing plugs to ignite a lower amount of fuel coming in at first. And cleaned and reset the mag. pick up. So far this seems it has fixed the problem.

I would say this. First the unit is still under warranty I would not go bending any thing. This would/could be a easy way out by saying you voided the warranty.
Secondly, tell the dealer to get his ass out there and fix it. It is not your job or responsibility to do his work for him. If he cannot or will not come and/or fix it call Generac and ask for another service dealer in your area.
Thirdly, I would make sure they check the WC on the gas line into the demand regulator, check the demand regulator its self,( had one that the "flap" was stuck on the diaphragm and couldn't open) and check the stepper motor to make sure it was working as should and getting the right voltage to it.
After rereading you post you could have water in the fuel line causing the flap to stick closed.
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Skip Douglas SkipD
I just went out and checked out my 5416 generator to see how the choke functions.

At rest, the choke was closed (covering one venturi fully and the other just a little bit). When I started the generator manually, the choke stayed closed for a second or two, then fully opened, then closed again. While closed, the engine fired. Once it was running, the choke opened fully and stayed that way.

The choke in my 5416 is controlled by a solenoid and is either wide open or as closed as it can be. There is no way for it to be in any intermediate position. Here is a photo of my unit with the air cleaner cover off:



The pen in the photo was used to point out something in an old post.
Skip Douglas
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bronco
So with the air box cover off will the choke plate move by hand and not stick open and spring back? If true then when unit is cranking will plate open then stick? I fplate is rubbing on air box then a slight bend up will take care of that and then should move freely. On the other hand some units had a problem with the plastic inside of the soleniod causing the plunger to stick inside. check these out if you want of have the dealer come out. I can understand why they don't want to come Generac only pay $50.00 for travel and that in most case's is not enough. But they are there to support the product and hopefully can get a service from you.
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Dave_eng
Update:
Tech from dealer came friday looking very professional in a new Mercedes van. Seemed well trained.
He said condensation builds up on choke shaft and freezes. He showed me a hole in the shaft and said as choke rotates this hole opens or closes some passage. He put gas line antifreeze on shaft. Replaced solenoid and asked me to run unit for 1 hour to get fully warm.
Now we just wait and see.
Dave p
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KevinBam
We are in Ohio and have had this many many times, this works for me, take the acutual spring out of the cylynder and wind it a little tighter. Its a pain and has to be done just right, but I havent had any issues since.
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GetTheNet
There is another thread about this issue as well... I was also told to bend the choke plate up. Not a chance since it is under warrty.... Call Generac explain what is happening. They will replace the choke unit.. Sorry can't remember the tech name. The problem is fixed. I have the 20kw and that is what they done for me and everything works great. As a matter of fact I am searching the forums about how long I can run the generator before it needs to be shut down. Going on 14hrs Big Ice storm here in Indiana.
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techntrek
I think the general rule is 100 hours, then change the oil. I've heard they use a lot of oil when run for long periods of time so personally I would check the oil every day and add as needed - leaving the oil change for after its all over.
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