OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines identify B&S motor please

Can you please assist in identifying this B&S motor
i have repainted all parts and have found no numbers at all the flywheel and magnetto numbers dont assit at all
There is a number 5 on the ally casting on the flywheel side

Nice job on the resto and looks like you have a great workshop.

As to what it is to begin with I would hazard a guess saying its early 70s since you have the flass fuel bowl and updraught carby, since the output haft is fairly small I would be guessing at 2-4 hp as my 5hp one has a larger diameter output shaft and my 3hp has the same as what you have. Cheers Joe.

I have a 1963 6 cubic inch (60102), and it has a down-draft carburetor with the fuel tank underneath, like the Briggs of the following twenty or thirty years. The one pictured above has the same snap-down spark-plug-shorting device for stopping the engine, but the carburetor and gravity feed fueling look older than mine.

check on the pull starter casing, there are always numbers on there refering to the engine model

i beg to differ i have 2 8hp briggs motors without it, they had decals on them with the model number....

We might make a basic start with a few features. I guess you had the recoil starter off it, during the restoration. Does it have one sprag on the inner part of the over-running clutch, or five? (The sprags have inclined planes that the balls roll up to lock and engage the clutch. There are several balls and recesses on the outer part of the clutch on both early and later clutches. What changed is the number of sprag projections on the inner part.) Only early recoil-starter engines had a single sprag - my 1963 one does, but the old manual from prior to 1980 describes that kind of starter as the early type. Reference:
http://www.tpub.com/content/recoveryvehicles/TM-5-4240-501-14P/css/TM-5-4240-501-14P_163.htm
(Use the "back" and "next" features to see other pages.)

Seriously ancient (WW2 vintage) small Briggs engines had a spring-steel device that flexed to short the spark plug and stop the engine, instead of the pivoted lever that yours and mine have. The pivoted lever was a revision of that system, and later still they introduced the relatively modern kill wire system that operates on the magneto primary instead of the secondary.

I've attempted to attach a diagram of the small two-piece flo-jet, which seems to be the carburetor you have. It seems it may have still been in use at least into the 80s, on gravity-feed fuel-system engines. Can you tell us the bore and stroke of your engine? That could be a useful clue as to which type it is - at a minimum, it will give us the displacement in cubic inches, which on the older engines is the first digit of the type number.

Thats about what i thought as to HP and the age seems to be 70s as you suggest from talking to the previous owner

there are no numbers anywhere as i have completely stripped and sand blasted all of the parts
thanks

Thanks for the link to the website as that gave me a lot of useful info
I don't want to dismantle the engine to do the bore and stroke but the stroke is 1.5 in if that assists (measured via the spark plug hole)and from memory it was approx 2" bore

the starter has the 5 sprags

You might try this site:
http://www.asecc.com/
The bore and stroke, and the "5" on the crankcase, would be consistent with it being an old Model 5, but it looks quite a bit different and I can't find any reference to them being made after 1957. That means it didn't have either a 5-sprag starter clutch or even a recoil starter. However if you fish around on that site you'll at least be entertained, if not enlightened. I think your engine was a successor to the Model 5S, but I think the 5S had a low fuel tank and a suction carburetor, like most of the 1960s, 70s and 80s small B&S engines.

Thanks for the assistance

You're welcome Marvic, I'm sorry I don't recognise the engine type. I've never actually encountered one of those very small (5 cubic inch, the smallest B&S engine size made in a very long time I think) gravity-fuel-feed engines. As I said, it seems to be a relatively recent successor to the 1950s small engines.

If you find the model number, please post it here - I'll leave this thread open.

Hi to Marvic and grumpy, I did some research and posted the pics on the ASECC website....This is the reply I received from Gary Stewart from Ohio:

"My guess is a 80300 series. The 8B etc had "B/S" stamped in raised letters on the shroud. The side cover is "different" with the casting below the bolt hole, and I don't remember seeing a gas tank bracket that was reinforced as this. This may be an exported engine and we just didn't see these here in the States. Hope this helps".

Hoping this does help,

There is something odd about his explanation, Deejay. An 80300 (i.e. an engine with the first generation of the five-digit code used by B&S from the late-1950s until the China expedition in the late 1990s) would have an 8 cubic inch displacement, whereas Marvic's engine is 4.7 cubic inches according to his bore and stroke figures. It sounds as if Gary Stewart was not aware of the bore and stroke. There were several different B&S 4.7 cubic inch engines in the 1940s and 1950s, with the Model 5 (and later the Model 5S) probably being the best known. The 5S had a vacuum carburetor instead of the older engines' gravity feed, and was made in larger numbers than the 5. It may have been the transition model, when B&S began to change their small light-duty engines to the vacuum carburetors and low fuel tanks that we are all used to. Marvic's engine indicates that after they made that transition they retained some gravity feed engines alongside the vacuum feed ones, perhaps for slightly heavier-duty applications. Marvic - from the pics it seems your engine has an aluminium cylinder - does it have a cast iron sleeve inside it, or an aluminium bore? The light-duty engines of the period had aluminium bores, and the heavy-duty ones had cast iron sleeves.

Hi grumpy, I will post this extra info....It may throw more light on it....someone must know what model it is, surely.

I think it is probably too easy for them rather than too hard, Deejay. I seem to have seen references to semi-modern 5 cubic inch engines somewhere. The bore is 2 inches and the stroke is 1.5 inches - both commonplace in very old B&S engines. You might mention that it has a 5 sprag starter clutch, not the old single sprag clutch.

Hi there It seems to have an alloy bore and from further inquiry MAy be off a type of cultivator . The motor hasent seen much use at all and shows no signs of any wear at all . Starts and runs real well

It's a nice piece of gear, Marvic, but I'd like to know what model it is, since I've never heard of it. Let's hope Deejay manages to find out from the ASECC collector group.

I hope to also know what model it is
I have seen a photo of a morrison reel type of mower (old one) that seems to have the same motor from what i can make out . There is no detail of the motor that identifies it however, that i can see