ZG222 gas in crankcase

[KubotaHawg]

Haven’t posted in awhile, but bought a 2015 ZG222 with 1000 hours for my son to mow yards.

one owner, clean, well maintained.
Ran fine for 5 yards last weekend, when started back up blew large amount of black oil out exhaust.

I pulled the carb and cleaned it, replaced and same thing. We just changed the oil and old oil was mostly gasoline. Replaced oil, oil filter, and spark plugs. Topped off gas with fresh ethanol free gas and added sea foam.

Restarted—ran much smoother, but still blowing large amount of (Black) oil out of the exhaust. After we let it cool down are going to remove the muffler and exhaust manifolds to see if oil coming from one or both cylinders.

I will call the guy tomorrow and see what he says—works at a JD dealer near here and has a Kubota experienced tech on staff. Seems like an honest guy, I don’t really question him, but just wanted to see if anyone has any insight.
I’m thinking a worn head gasket? But don’t have a lot of deep engine experience.
Thanks all

 

[GreensvilleJay]

possibly....
... cause gravity sux.... ?

gas tank is high, carb is low......

if the 'antidieseling' solenoid on the carb doesn't completely close, gravity pulls gas from tank into carb, then past rings, into the oil sump/ crankcase.

I've seen this so many times on 'riders' , I install a manual shutoff in the gasline.

 

[KubotaHawg]

possibly....
... cause gravity sux.... ?

gas tank is high, carb is low......

if the 'antidieseling' solenoid on the carb doesn't completely close, gravity pulls gas from tank into carb, then past rings, into the oil sump/ crankcase.

I've seen this so many times on 'riders' , I install a manual shutoff in the gasline.

Gas tank is below the carb, but I think the float may be shot—especially if previous owner didn’t use ethanol free gas. It sat from fall til now so that may be the case.

Looks like may be hello Messicks for a new carb

 

[DustyRusty]

If he mowed 5 yards with the lawn mower and it was fine, then it was fine when you purchased it. You bought a 1000 hour used lawn mower, and the seller has no obligation to do anything for you. That is the risk that you take when purchasing a used piece of equipment. You didn't say what the engine was, however, there are a few things that you can do to determine what is going on with the engine. I would start by doing a compression check to see how good the rings and valves are. A 1000 hours on these small engines is a lot and most likely you are looking at either an engine rebuild or replacement.
According to the "internet" that is a Kubota KGZ770-E2-M3 Gasoline, Air Cooled V-Twin engine.
If he is going to be doing multiple lawns at a time, then diesel is the only way to go. Most small gasoline engines are at the end of their useful life at 1000 hours.

 

[GreensvilleJay]

It shouldn't be the float...as gas has to get past the 'antidieseling' solenoid first.
You did say you 'cleaned the carb', but did you remove and service the AD solenoid ?

 

[KubotaHawg]

It shouldn't be the float...as gas has to get past the 'antidieseling' solenoid first.
You did say you 'cleaned the carb', but did you remove and service the AD solenoid ?

I didn’t, that’s going to be on my list for today. I am not familiar with the AD solenoid as have only worked on stihl or outboard carbs before and they don’t have that solenoid. Thanks for the suggestion.

 

[KubotaHawg]

If he mowed 5 yards with the lawn mower and it was fine, then it was fine when you purchased it. You bought a 1000 hour used lawn mower, and the seller has no obligation to do anything for you. That is the risk that you take when purchasing a used piece of equipment. You didn't say what the engine was, however, there are a few things that you can do to determine what is going on with the engine. I would start by doing a compression check to see how good the rings and valves are. A 1000 hours on these small engines is a lot and most likely you are looking at either an engine rebuild or replacement.
According to the "internet" that is a Kubota KGZ770-E2-M3 Gasoline, Air Cooled V-Twin engine.
If he is going to be doing multiple lawns at a time, then diesel is the only way to go. Most small gasoline engines are at the end of their useful life at 1000 hours.

You are correct on the engine.

I look at it as a Kubota or Kawasaki engine used 100 hours per year for 10 years (by one owner, with a big yard) is a much higher quality engine in the first place and worth putting some maintenance and money into than buying a cheap box store zero turn that’s built cheap.

Even if it is very clean and maintained—it is—it’s still 10 years old and I figured some maintenance of expected wear into the cost. I have talked to the seller as he’s a good fellow who works with a Kubota tech and has been really helpful. He doesn’t owe me a thing but has been super nice and trying to help.

 

[KubotaHawg]

You are correct on the engine.

I look at it as a Kubota or Kawasaki engine used 100 hours per year for 10 years (by one owner, with a big yard) is a much higher quality engine in the first place and worth putting some maintenance and money into than buying a cheap box store zero turn that’s built cheap.

Even if it is very clean and maintained—it is—it’s still 10 years old and I figured some maintenance of expected wear into the cost. I have talked to the seller as he’s a good fellow who works with a Kubota tech and has been really helpful. He doesn’t owe me a thing but has been super nice and trying to help.

Actually my first thought was what the hell did my 16 yo tear up on a mower that ran perfectly when I put it through its paces before buying. If you have teenage boys you get it…

 

[KubotaHawg]

Looks like it was the seals/O rings on the float cylinder—dry rotted once I looked at it closer. For future information for anyone, hard to find seal/rebuild kit for this carburetor but it is same as common Kawasaki engines. New carb on messicks: $696. New aftermarket carburetor on amazon (5* reviews): $34. Will use the float bowl with new AD solenoid on the original carb and have a spare carburetor.