3311X6S - just purchased - questions about engine

[Dhermesc]

I just picked up a fairly nice looking 3311X6S (I am guessing on the 6 - can't remember for sure). I was little surprised to see it was a 1980's model - by the looks I had assumed 1970s or earlier. The previous owner told me about all the trouble had trying to get it to run and how it had sat for years in a storage locker before he bought it. He assumed it just needed a new carb instead of rebuilding it - he claimed to rebuild it twice and had parts from the rebuild attempts. He got it to run pouring gas in the carb and it would run for 30 seconds then shut off. Paid him $80 in cash - I had to load myself.

Brought it home and thought I might give the carb a shot - pulled the fuel line and just the tiniest dribble of gas. I was going to drain the tank anyway and opened the shut off valve - still just the tiniest dribble of gas. Freind of mine has a few of these - sold me an entire gas tank with no shut off valve (installed inline valve and filter) cleaned it and hooked it up. After about 20 pulls it fired up and ran decent.

I have an owners manual for the mower - but it does not cover the engine at all. What model of Briggs 11 HP engine does this have? The model number was sanded off, but the model type is a 0181-01 Serial number 78121411. The model number might end in 707 or just 07. The control unit for the carb needs some adjustments and possibly springs as the choke will not work at all (the current reason why its hard to start).

What engine would this have - can you get a manual?

Second question. This has a fairly large air filter. It has two "hold down" screw holes. One that attaches to support on the engine. The second hole is directly over the throat of the carb - just like the smaller engines single hold down screw. But there is no threaded hole in the throat of the carb - missing? Or am I looking at something wrong.

 

[StarTech]

Being a late 1978 engine it is one of the following engines. With the air cleaner having two hold downs that eliminates the 28M engine.

 

[ILENGINE]

And being 33 inch with 11 hp I would bet on one of the 25 series engines being it.

 

[Dhermesc]

Being a late 1978 engine it is one of the following engines. With the air cleaner having two hold downs that eliminates the 28M engine.

View attachment 68654

Question - what does the last digits indicate? On mine 0181 01 - you searched 0181 99? Is there any significance to those digits? I know basic small engine stuff - (primarily Kohler 301, 321) and next to nothing about Briggs.


To be honest I have no idea if this is the original engine, or the original shroud. It appears "period correct" for the mower.. It is white and it says 11Hp, with a pull rope and an electric starter. The guy before me decided to "restore" it and got as far as everything that was white - the engine, steering handles and wheels.

 

[Mow Joe]

252707 would be correct for that mower, but the date code of 78 would not. The series 6 was late 80's. The engine has been replaced, or at least the blower housing. Numbers being ground off was not that unusual. Engine mfrs. frowned on equipment mfrs. selling off unused engines to surplus supply houses, etc. Surplus dealers, or the sellers, would grind off some numbers so the engine mfrs. would not know who was selling to them.