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Hello,
Never had to think much about this red Murray rider. It always started and runs good except for the time a mouse built a nest under the cylinder cover. I don't have the Model specifics, it is a 11 hp, 30" and I'll start a thread on the problem that occurred today. But first, is the engine worth working on? Oil is shooting out of the air filter box from breather or carb, stopping the engine. Not much information I can find on the Briggs & Stratton 28R707 like there is for the other overhead valve engines.

Thanks,
Chris C
Wisconsin

Probably a failed float in the carb or blown head gasket
Both easy fixes.
But I will wait to post any more till you start the new thread.

The Briggs single cylinder OHV service manual covers this engine. Also need the type number to narrow which of the 19 versions you have but check what Bert posted.

It is an older red Murray 30" riding mower. Rear engine. 11 h.p. Briggs and Stratton engine. The model for engine is 28R707 - 1120-E1 and type Q3080820 from the tag. Maybe you can get an idea of the year from that last number, I can't or copied it wrong.
I did notice I was completely out of gas before starting yesterday. So empty I only managed to drive it out of the shed 6 feet. In the last few weeks there has been just a bit of odd hesitant starting compared to previous experience and a small pop backfire a couple times when shutting off. These are things I noticed and wouldn't be concerned if it weren't for the geyser of oil from the air box(?). Otherwise it was running fine.
What happened was it was ruining normally and cutting for about 1 minute yesterday. The engine died and wouldn't restart. I had just filled gas so I checked air filter, didn't look terribly bad but I tried starting with it off. It started and seemed ok. Put filter back on, no start. Removed and drove to the house. Ran it again, cutting without the filter and it stopped exactly where it did before after 1 minute. When I looked into the engine compartment it was full for splattered oil everywhere. It idles but no sign of what's going on and with engine cover in position I can't observe while it's cutting.
I tried doing some research but can't find much on this type of engine. I am not familiar with small engines enough to know what to do next. I would be totally comfortable if I had a direction and information for a repair.
Checked the dip stick this morning and can't see or smell anything abnormal -- I was looking for gas.
I do like these simple, small lawn tractors and would love to get it back in service.

With the 28R707-1120-E1 model number it is an old L-head engine and not OHV as I previously mentioned. and date code is probably 03080820 which would make it a 2003 engine.

You need the Briggs 270962 Single L-head service manual.

I was thinking it was too and watched a few videos of gasket replacement. It looked like the kind of stuff I like to do. But with this L-head, is it likely to be a head gasket?
Do you order a service manual or download it somewhere?

See all that dirt and grit just sitting where the air filter goes? Clean it to resemble a new part. That grit can get sucked into the engine doing cylinder bore, cam and so on damage.

Since this is an older engine....

1.Have you ever pulled the metal engine shroud and cleaned the top of the block and cooling fins? This is a yearly maintenance item in ALL engine manuals. Neglect this and you are looking at engine damage.

2.Need to pull the head. Remove all carbon from the piston face, head and valve area. Chunks of carbon will flake off getting between the piston and rings. These ultra hard chunks will gouge the cylinder bore causing the engine to smoke. Should be done say every 3-5 years. Depends on how much you mow. Commercial lawn crew, more often. Home owner say every 5 years'ish.

I have the filter off to troubleshoot only.

Cleaned under the shroud completely a few years ago.

Most likely will remove the head when I figure out procedure and have a diagram. I'm searching now.
I do have a hardware store and a good small engine implement shop nearby.

This Murray gets used maybe 10 hours a year or less, light duty.

At "Manualslib" I find Briggs 270962 Single L-head service manual, but when I click on it it takes me to the OHV 276781 manual.

i believe this is what you need

Tiki Vegas said:

At "Manualslib" I find Briggs 270962 Single L-head service manual, but when I click on it it takes me to the OHV 276781 manual.

Click to expand...

THANK YOU.

I'm still trying to figure out if there is a gasket failure or the carb is leaking into the cylinder while it sits. This will help. I'm open to suggestions.

i would keep a check on a fuel level... maybe mark it with a sharpie on the outside of the tank if it's transparent enough to see the fuel level.

Good idea.
If you can believe, after my catastrophic panic, it starts, runs and cuts now even after about 15 minutes of use. So I'm still confused. I'm gonna change the air filter and the oil. I'd think the oil would be much darker than it shows on the stick so it may be contaminated. Usually if something goes wrong once, it's not gonna go away.

Scrubcadet10 said:

i would keep a check on a fuel level... maybe mark it with a sharpie on the outside of the tank if it's transparent enough to see the fuel level.

Click to expand...

Or a stick inside the tank.

My best guess is that the float needle in the carb did not seat properly, allowing all the fuel to drain through the carb into the crankcase. Is the oil level above the full mark and does the oil smell like fuel? If so it would confirm my guess. Remedy would be to remove the carb, clean and rebuild it using the proper carb kit. If I’m wrong, he who knows more than me and tell me I’m wrong and give you a better answer.

On that now priceless engine, I would install a fuel shutoff valve and filter inline with the carb. Use the shutoff at every mowing.

Glad to hear she's a runner.

slomo said:

On that now priceless engine, I would install a fuel shutoff valve and filter inline with the carb. Use the shutoff at every mowing.

Glad to hear she's a runner.

Click to expand...

I thought you were sorta joking, but you don't realize how much you depend on these old engines until it goes down.

Tiki Vegas said:

I thought you were sorta joking, but you don't realize how much you depend on these old engines until it goes down.

Click to expand...

Briggs is no longer making parts for a lot of these older engines. Sad to see as these are their better products. New stuff is full of plastic cams and carbs.....

Plastic carbs ain't horrible... A lot less corrosion when you leave fuel in them.

Tiki Vegas said:

I have the filter off to troubleshoot only.

Cleaned under the shroud completely a few years ago.

Most likely will remove the head when I figure out procedure and have a diagram. I'm searching now.
I do have a hardware store and a good small engine implement shop nearby.

This Murray gets used maybe 10 hours a year or less, light duty.

Click to expand...

You have plugged block vent I would check the pcv valve for proper operation (not stuck) then any vacuum lines on the engine to make sure they are not plugged