Dixie/Generac Engine failure question

Hurst · Sep 29, 2014

Our 2011 2750 Dixie with a 27hp Generac decided to lose a cylinder today at 775 hrs. I pulled the valve covers to see what the valves were doing (hoping it might be as simple as a rocker or valve spring problem). The dead cylinder has an exhaust valve that is staying partially open. It pushes in by hand and comes back up hitting something solid, but it is not returning all the way. Is this the symptom of a burnt valve or broken valve seat? The valve lacks about 1/8" from returning the the same position as the intake valve. The other cylinder's valves match when they are at TDC. Pressuring through the spark plug hole just pushes air straight out of the exhaust with the cylinder at TDC. I am hoping at worst it is just a new loaded cylinder head and gaskets.

Thanks in advance!

Hurst

GregCO · Sep 29, 2014

Sounds like it dropped a valve seat. Easy to find out. Pull the head and have a look. Hopefully it didn't hurt the piston top.

Greg

Hurst · Sep 29, 2014

I guess with a horizontal engine, the seat will hook around the valve stem and not let the valve close? The engine still turns over fine by hand and didn't have any sounds of interface when it did this, just started missing and back firing. Guess I'll pull the head in the morning and take a peak. What really yanks me is the engine is under warranty, but it only covers parts, no labor. Dealer said it would be $350 at least for a simple head problem repair just in labor (5 hrs at $70 an hour) and the head is only about a $150 part, but they won't warrant a part if I do the work at my farm shop... Might be the last Dixie I own with this warranty... and then we had to replace all the hydraulic hoses, 2 of them out of warranty, b/c they started leaking around the crimps (one blew the hose out of the crimp!).

Hurst

JD Seller · Sep 29, 2014

IF this is the same company that makes the Generac generators then I am surprised you got 775 hours on it. I have seen several of them not last 200 hours on generators.

I would take a Kohler over a Generac and a Honda/Kawasaki over the Kohler. B&S would be right there with Generac.

All that said I will second that you more than likely have a valve seat that has came out of the block. If the seat is not beat up too bad I have had fairly good luck reinstalling them. Pull the valve out and drive the seat back into the bore it goes in. Than take a center punch and stake all around the seat. Lap or grind the valve seat and reinstall the valve.

I have seen some that last for years after that. Some don't last five minutes either. LOL

If the warranty covers the parts then I would replace the block. I wonder if they will spring for a short block??? If they don't I would make sure they give you new piston rings.

Might be a good time to "trade" after you get it running.

GregCO · Sep 29, 2014

This is an over head valve engine right? If so I would pull the head and if it is a seat that fell out. you can do like JD Seller stated and drive it back in and use a center punch to seat it and keep it in place. I have seen many last a long time like that and some that don't, but all you are out is a head gasket and some time.
Dixie isn't a bad coach and I wouldn't kick it to the curb for a bad gen set. Upgrade the gen set and it will go or many more years.

Greg

notjustair · Sep 29, 2014

Welcome to the world of Generac. I didn't get anywhere near that mileage before I started having trouble (generator). I ran screaming and found a sucker dumber than me.

I have NEVER had luck with rebuilt heads where valve guides or seats were concerned. They always end up lasting until I just begin to trust them and forget about the pain of the repair and then let go on me. See what a new head runs and then decide if it is worth it. I doubt it, but it may be. Maybe you can find someone on fleabay who has had the same thing happen and now has a head for sale. You're on borrowed time with that paper weight anyway.

T.R.K. · Sep 29, 2014

If a valve seat worked loose, it probably overheated. Another thing that can produce the same symptom is a valve guide moving in the head. I would remove the blower cover, check to be sure the fins are clear of debris. If the engine has a lean surge, revs up and down, clean the carburetor.

Also, The Generacs I am familiar with are very sensitive to their oil level. I have seen several fail-broke rod- at about 40 to 50 hours and the oil was only 1/4" or so below the add mark.

The oil aids cooling, so keep the level in the operating range.

I worked on a 33 hp. Generac with 1300+ hours on it this morning, so they aren't all junk. (That customer does service her mower regularly, however.)

Hurst · Sep 29, 2014

They said if it was a valve seat or burnt valve they would just put a new head and gaskets on and send it out the door with me paying for labor. I am just debating on staking the valve seat vs buying a new head. Does this indicate the engine was running hot? They were only mowing light grass, so nothing that would load the engine and we keep the cooling fan and fins blown out. I guess if I stake it, the seat may just pop out again, it seems like it isn't prone to breaking up and messing up the engine.

Hurst

Hurst · Sep 29, 2014

This mower gets Rotella SAE30 every 100hrs and I fill it right to the full mark. Have never had it come in for service low. Might run some sea foam through in case there is some junk in the carb causing it to run lean. I'll check the fins as I take off the covers, but we keep it blown out on a regular basis. Has me stumped, but I guess I'll find out tomorrow when I start taking covers off and get the head off. Mower runs smooth and idles smooth, never have noticed a surge from it. Might be worthwhile to richen it a hair since a lot of these engines come right on the edge of being too lean due to emissions.

Hurst

Hurst · Sep 29, 2014

It is an overhead valve engine. The dealer said they keep heads on the shelf, that makes me wonder how long until I am going through this on the other cylinder! lol

Hurst

GregCO · Sep 29, 2014

I feel like an idiot. I thought we were talking about a Dixie motor coach with a gen set in it.

GregCO · Sep 29, 2014

I know how you feel. The ignition switch in my truck sent south and I called the local chevy dealership and they had 12 in stock. I asked how often they went bad and was told almost never. And you have 12 in stock?

Greg

Ronnie Graves · Sep 29, 2014

no punching just some LOCKTITE stud and bearing mount put some on it and put back in place
check the other ones while you got it off
I fix them all the time havent had one come back yet

Texasmark1 · Oct 1, 2014

On they aren't junk, they advertised the other day a celebration for their 1 millionth unit sold. Quite impressive. I installed a 11kw in my yard this spring. Am thrilled.

The engine on mine was specifically designed for the purpose by them. It's all automatic. Runs about 15 minutes on it's own once a week. If power goes out it waits 10 seconds to determine it's not a glitch and starts the engine.

Then 5 seconds of engine start/run time and then WHAM the contactor changes the power source to the house and you are back in business. If you have your computer plugged into one of those battery inverters, you never know it happened.

But I do, I can hear the WHAM. Great! Soon as the power is restored it senses the fact, contactor WHAM back to normal and engine goes through a few minutes of cool down and it shuts down. Pretty simple. All automatic.

Mark

Dixie/Generac Engine failure question

Hurst

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GregCO

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Hurst

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JD Seller

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GregCO

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notjustair

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T.R.K.

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Hurst

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Hurst

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Hurst

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GregCO

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GregCO

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Ronnie Graves

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Texasmark1

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