My Tractor Forum banner

1 - 20 of 38 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Hopefully someone can give me some insight on this...

Just the other day my machine was kicking out white smoke while I was using it under low throttle. I throttled it up and it was all fine. I thought nothing of it until later that day white smoke was coming out just a little at full throttle.

Today I went to start it up and loads of white smoke once it was warmed up.

I did some reading on this forum before posting this.

My breather on one of the valve covers was leaking bad. Oil all over, so I sprayed down everything with a hose to remove some of the oil. Cranked it back up and no smoke. Not until about 3min running. It started slow and then started blowing a lot. The engine still sounds just fine and nothing changed from no smoke to smoke as far as the sound. When I shut it off, it back fired. Each of the three times I had it on today it backfired when I shut it off...

What are the thoughts here?
 

·
Premium Member
Joined
·
9,670 Posts
Oil breather is pluged up or not functioning properly. It has a reed type valve. I have taken mine off, cleaned with carb cleaner and re-installed with a new gasket. No smoke.
 

·
Banned
Joined
·
7,239 Posts
Just to be safe, you might want to smell the oil for the presence of gasoline.
A leaky carb needle/seat assembly could allow gas to pass through into the crankcase and dilute the oil.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #4
First off let me say thanks for responding!

This is a bit frustrating since I only recently got this machine. Right in the middle of a bunch of projects, mainly my shop. So working on this machine doesn't sound like a fun time at this point.

Ok, enough crying. I pulled the breather off and I can blow through it freely in both directions. Line is a little cracked but that shouldn't cause white smoke after it's warm...

I smelled the oil. I don't detect any gasoline in it. Smells burned normal used smell...

Any other thoughts here?

Just something I thought of... Isn't white smoke an indication of richness? If so I wonder if a plug is fouled? Though if that's the case wouldn't it run really rough? It runs fine.
 

·
Premium Member
Joined
·
9,670 Posts
It should only vent "IN" to the crank case, not "Out"

Edit: I may have that backwards, but it should only vent "one way"
 

·
Senior MTF Poster
Joined
·
13,173 Posts
The vent should have little resistance out and quickly switch to slight leakage in.

Another good possibility is that you have a leaking head gasket, Check spark plugs.

Walt Conner
 

·
Registered
Joined
·
48 Posts
"This is a bit frustrating since I only recently got this machine."

Since you probably don't know the full history of this engine, you can't assume that it was maintained properly. The symptoms you describe (more smoke when warmed up and at full throttle) point to worn or broken piston rings along with cylinders worn or out-of-round. You may need a rebuild....

You also might want to post the make and full numbers from your engine to get more specific help. The GT5000 was made with both Briggs and Kohler engines....
 

·
Registered
Joined
·
19 Posts
Discussion Starter #8
I don't have the numbers in front of me at the moment but it's the Kohler engine.

If it was worn rings etc it should slowly start smoking and get worse over time. It just started suddenly. I used it one day for about two hours and towards the last 15min or so I could tell a tiny amount of smoke. The next time I started it is when it started smoking like a BBQ.

I'll check the plugs tonight when I get home.

Thanks guys.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #10
How can I determine for sure if it's a blown head gasket or not? I don't want to tear into it and then that not be it. Ugh.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #11
Done a bit more troubleshooting...

I notice when I throttle it up and have a load on it. Dragging dirt it starts to bog out and wants to die.

When it's under load and wanting to die if I pull the breather or the dip stick out she throttles back up again... But with the breather out if I go to drag dirt again she will bog out...

I can blow through the breather both ways clear, I sprayed it out with carb cleaner and the same thing... Odd, thoughts?
 

·
Registered
Joined
·
1,070 Posts
Sounds like it is running on one cylinder. To find out, start the engine and pull one plug wire. If you don't notice anything different then pull the other. If it is running on one cylinder when you pull the plug wire on the good side the engine will of course die.

White smoke usually indicates that gas is getting into the crankcase. this can happen from a number of causes. If the carburetor has a shut-off switch built into it it could be bad and allow gas to leak after shutoff. As the bowl overfills, the gas leaks down into the crankcase which dilutes the oil.

Not knowing the exact engine you have makes diagnosis a little tricky but I assume that it is an overhead valve engine. On some Kohler engine there is a reed valve inside the head cover which allows oil to enter the engine but closes and oil returns through a vent hole. If the oil is diluted by gas and is overfilled it fill up the valve cover faster than it can return and then get into the head and cause white smoke.

check the Carburetor for a wire running to it. If it has one then turn your key switch to the on position while listening for a click at the carburetor for a click. If you don't hear one tap the place near where the wire is attached while clicking the key on and off. Then come back and tell us what happened. Check the oil for overfill. If it is high it probably has gas in it.
 

·
Registered
Joined
·
2,160 Posts
I'm going with blown head gasket crank becomes pressurized sending oil into carb , plugs become fouled. White smoke is burning off coming out exhaust. Sounds silly but Baby powder around head gasket will puff at leak exposing blown gasket location. Backfiring can be a clue of blown head gasket and make it worse!
 

·
Buy High, Sell Low
Joined
·
511 Posts
Having owned 3 of these exact tractors. I concur, it will need the improved head gasket/bolt kit installed. Not too terribly difficult to do, but a PITA nonetheless. Search in this forum and there are some great threads that walk through the process. Once reassembled with the improved gaskets you will be amazed at the difference.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #15
Apparently it is running on one cylinder (at least one of the problems…)! The right side spark plug (if you're sitting on it) is fouled. I pulled it and fuel/oil is in between the spark points. I connected the plug and fired it up and there is defiantly spark through to the plug. Very bright blue.

The spark points are clean in color other then that. I wiped it off and put it back in three different times. Each time I pull it out, the same thing as first mentioned...

I don't see a fuel cut off in the fuel line. And I do have a wire on the carb and when put in the on position I do hear it clicking. I tired it multiple times and head it each time...

The oil and fuel in that cylinder, should I let it sit a few days to hopefully have it drain down? Not sure why oil would be in there but stranger things have happened I suppose. I say oil because it feels a bit slick unlike fuel alone...
 

·
TECH Exchange Contributor!
Joined
·
582 Posts
My vote is for blown head gasket.
The 25 hp on the GT5000 are very notorious for it. I have repaired at least 4 of them - one of them twice. The first time was when it had only 100 hours on it and they did not have the upgraded kit out yet.
On all of them it was the right hand side cylinder - just like you are describing. The plug will foul up and the engine smokes. It can be anything from just a slight smoke when changing engine speed to a full blown smoke screen.

The kit is around $ 25 and it will take a few hours to fix it. It is not all that difficult. Just download the repair manual from Kohler's site and find the section on putting the heads back on so you can get the correct torque settings and sequence. I highly recommend to get a torque wrench if you don't have one.
I am just using the cheap HF ones - they work fine for a weekend mechanic like me.

Hope this helps.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #17
Boy.

Where can I buy that kit? If I walked into sears would they have it? Are all the new head gaskets, "upgraded" ones?

Thanks folks.
 

·
Registered
Joined
·
1,070 Posts
Boy.

Where can I buy that kit? If I walked into sears would they have it? Are all the new head gaskets, "upgraded" ones?

Thanks folks.
Don't get ahead of yourself. Take it one step at a time. First you must determine what the problem is. You must find out if it is firing on both cylinders and then which one is not working. I may be something simple.
 

·
TECH Exchange Contributor!
Joined
·
582 Posts
Boy.

Where can I buy that kit? If I walked into sears would they have it? Are all the new head gaskets, "upgraded" ones?

Thanks folks.
Any new ones should be the upgraded version.
If you have a Sears parts center they will likely have it. At my local one they always stock them as they have sold a lot of GT5000 and have a lot of them blow the gasket.

I agree to test out first, but based on your description with a fouling plug and my experience I would feel pretty certain it is the head gasket. In other words if it was sitting in My garage I would not hesitate taking it apart and buying the gasket kit.

If the local Sears doesn't have it a small engine dealer may or you can buy it online. I usually have good success with jackssmallengines.com but there are many others out there.
 

·
Briggs powered Sears.
Joined
·
2,856 Posts
the side thats not firing do a compression check just to be on safe side
 
1 - 20 of 38 Posts
Top