Craftsman Lawn Vacuum

[lefty]

Engine Craftsman 143.014500 (says tecumseh on the top)
Lawn Vacuum 247-770110 24B-031E099

This came to me from a neighbor. He says it was running fine for a whole day. The next day he pulled it out and it wouldn't start. After many attempts, he says he turned it up on its side toward the side you would to drain the oil. I'm not sure why. He said after that, it locked on him.

When it arrived here, I immediately checked the oil and there was fuel in there. He pulled it over and fuel shot out the muffler and was spilling from the carb. I also noticed fuel coming from under the cylinder. Head gasket?

So I started pulling it apart and there was fuel everywhere. Many ounces in the cylinder and it's just pouring out of everywhere. When I removed the spark plug, it just poured out of there. The intake manifold on this one travels down from the carb at a 45% angle so I'm assuming the needle was stuck open and fuel just kept pouring in.

My main concern is that it appears to be leaking from the bottom of the cylinder.

I'm thinking I need to take a look at the carb and perform a leak down to verify whether or not I have a blown head gasket? Also, drain the oil obviously. Am I on the right track here?

[bgsengine]

I would suspect so also observe if the cooling fins may be plugged or blocked even a little - most common on these little L-heads (Briggs too) is the head gasket to blow out around the exhaust valve area (though on your tecumseh the exhaust valve is at the top) but that corner is the furthest point from any cooling air flow so they are prone to overheat related thermal break down of the head gasket.

If it was me, I'd just get a head gasket and pull the head anyhow - They often can start up just fine even with a slightly blown head gasket but it may likely have finally burned out enough to cause the hard start/ no start. gas in the cylinder would be why it locked up on him - also known as hydro-locking So you probably should plan a carb service and pull the top covers, clean cooling fins, replace head gasket and pull valve cover and check your valve clearance - also make sure you roll engine til valves open and check if either of the valve seats is loose.

[lefty]

Thanks BG.

Just so I understand, are you saying that the head gasket trouble could cause the fuel in the cylinder or are the two problems unrelated?

[bgsengine]

Thanks BG.

Just so I understand, are you saying that the head gasket trouble could cause the fuel in the cylinder or are the two problems unrelated?

they are unrelated gas in cylidner and sump comes from leaking out the carb, typically caused by dirt or debris in carb. blown head gasket typically caused by overheating, which commonly would be caused by blocked cooling fins - bear in bind for what it is used for a lot of leaves blocking the air intake (through the recoil starter rotating screen and flywheel) will also cause overheating.

[lefty]

Thanks. This one is such a mess so I'm going over it slowly. I removed the carb and fuel tank and am cleaning the machine off and inspecting. Today, as I looked at it a bit, it appears that the gas/oil mixture is leaking through the sump gasket in the front center, about in line with the spark plug. It continues to leak out of there...even today, a couple days later.

I inspected the head gasket area and that doesn't appear wet. Not saying it doesn't need one but I'm just trying to figure out where the fuel is coming from. Maybe it's coming out the exhaust and running down so it appears to be coming from the sump gasket? Maybe because the oil now has the consistency of water it's leaking out areas it normally wouldn't? Maybe past the valves, out the valve cover and dripping down? I've never seen that much fuel in the oil. I mean, it was wild. I haven't drained the oil yet because I want to make sure there isn't more here than just a stuck float needle.

A small adjustment to the original back story as I spoke to the owner again today. It ran fine for a few hours a couple weeks ago. He put it away and pulled it out the other day and it hydro locked immediately on the first pull with no start obviously. He then put more fuel in it and tipped it up to check underneath, which obviously just poured more fuel into the cylinder.

So I'm guessing the needle stuck open a couple weeks ago when he put it away and the sump just filled with fuel as it sat in the shed. Can fuel eat away the sump gasket? And if so, that quickly?

In the photos below you can see the front of the machine covered with a gas / oil mix. I've cleaned it off several times and it keeps coming out of somewhere but not the spark plug hole and does not appear to be coming from the head gasket.

[KE4AVB]

The easiest way to find a leak that not obvious is to use an UV dye and a good UV light source that meets the UV dye specs. Here I used Interdynamics Oil and Fuel Systems UV Dye and a 365nm UV light hand held light.

[bgsengine]

could be a leaking sump gasket - also relatively common especially right in that area just back of the cylinder - if it was disassembled you will usually find (in those cases) the gasket is "sucked in" to the crankcase in between two bolts either side of the cylinder bore - happens quite often on many engines - that's a weak spot for the gasket and with seasonal equipment stored for a long time and never run, the gasket tends to dry out and shrink (harden) and cracks in that area then gets sucked in (because the crankcase typically holds a slight vacuum when running) so you may end up having to pop the sump off and replace gasket and oil seal too = if you clean it off along the gasket line behind the cylinder cooling fins and watch for thinned oil to seep back out, you found the problem. In such a case I would also pull the head and valve cover anyhow and replace those gaskets too, along with all the other checks.. Of course it's usually labor intensive and depending on shop rate, may be a "scrapper" unit depending on the shape of everything else.

[lefty]

Thanks for the help guys. Sorry for the delay in responding to the post....day job has been busy. Being that I don't know how long this machine has been running with fuel in the oil I figured it would be a good idea to run a leak down to make sure it's worth tackling. I had 100 in and about 84 on the other side. So I guess that's 16%? Is that O.K.?

Also, regarding the sump gasket, this will be the first time I pulled anything off a machine like this that wasn't just a regular blade. I'm guessing whatever is attached to the crank has to come off to take the engine off to get at the sump gasket. Any words of wisdom in case it comes to that?

Thanks

[lefty]

Is it ok to use cork material for the gasket on this between the intake manifold and engine? I have a sheet laying around from advanced autoparts. I imagine it will have to deal with some heat.

Thank you

[KE4AVB]

Personally I would not use it due it tends to compress and shrink a lot during use. Perfer to regular gasket paper over cork. If you ever dealt cork valve cover gaskets you will know I mean resulting leakages. The Kohler Courage single cylinder is prime example of this. Can't even keep the RTV sealant sealed more a season on these here.