OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines B&S 11HP vertical shaft - electric start

I have aquired the above engine when I was given a double pulley for the Greenfield slasher - it was attached to the pulley. A bit weathered from sitting in a ride-on stuck in a bog in the open - muffler is shot - starter cord broken - bit of corosion here and there - turns by hand - air filter missing. Fuel tank has the remains of something that resembles petrol and there is oil in the sump.

How can I tell if it is worth getting running? Can it be compresssion tested? How can the ignition be checked? - Would there be a market for this size engine if going in good order?

I do have the B&S manuals on disc ( haven't check what's on it for this motor yet)

Because of the inbuilt decompressor, i think the procedure for testing compression as outlined by Briggs is to rotate/spin the engine by hand toward the top of the compression stroke (a sort of flick of the wrist) and the engine is meant to bounce back a certain amount.

Grumpy will know more about it.

As the piston raises up to the top of the stroke it builds compression and just before TDC the exhaust valve will lift slightly, so its like theres two TDC's on the compression stroke if you are turning the motor by hand. Well two stages.
I would assume the theory is that in the first part of the compression it should build enough. The above spin method does have its flaws, any drag on the crank will effect results as will altering the reciprocating weight of the engine. The Greenfields pulley being a billet of steel weighs a hell of a lot more than the pressed steel pulleys ive seen on other machines.

You can use a tester, if you have another motor there similar or same, and compare the PSI readings. Something better than 60 or 70 psi rings a bell.

I dont bother any more, i used to compression test the mower engines (3-5hp) but i just pull the head off and have a look now. Set the valve clearances and put it back together. Then see if it smokes. Sure compression pressure is relative to ring wear but so is smoking, a motor that does not run at full efficency due to worn rings will still do its job for a long while, but one that smokes will be a hard sell.


I would suggest you do the same.
Fix the starter.
Check the spark, see if thats OK.
Pull the head off, inspect the bore and set the valve clearances.

Whats the carb like?? You said that the filter is missing, has it had water in it?? Has water got in the motor.
Carb (and exhaust?) will need to come of to check the valve clearances.

If the motor does not pass the test it is very sellable as parts and/or worth keeping.


With a cast iron flywheel the motor is safe to start and run with nothing on the crank.
I would suggest an old table or desk, drill a hole, cut a hole out with a jigsaw and bolt the motor down with 2 bolts.

Cheers, Bob.

David, the first thing we need to know is the long string of numbers stamped on the engine's cooling air cowl. With those we can find out quite a bit about it.

I realise I need that number to - I'm in Brisbane till tomorrow night - home on Friday - will look it up then.

Number on the cowl is 253707 0169 01 85011010 - B&S site says it doesn't exist - and yes I have double checked with steel wool, degreaser, a 3x reading glasses

You have omitted the first block of numbers, David. There is a 6 digit block of numbers called the model number that comes before the 0169-01, which is the type number, and the 85011010, which is the manufacturing date and assembly line number, called the code number. In case it is useful, your engine was manufactured on 10 January 1985, but that is as far as we can get without the model number.

Sorry added that later and our posts crossed - it was buried under thick paint and the numbers were faintly etched - had to scrap the paint off to find them. Still had trouble finding it on the B&S site - they keep showing the example numbers with hyphens but when you search you have to leave the hyphens out and join the numbers into one

Howdy, if you go to www.partstree.com, you can search there. Just search for 253707-0169-01, and it'll bring up all the parts listings.

Your engine is 25 cubic inches (410 cc), fourth design generation, with vertical crankshaft and flo-jet carburetor. It has plain main bearings and a 12 Volt geared-type electric starter with alternator. Here is the illustrated parts list:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6nlyHVJ1DajI.pdf

Here is the operator's manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msoBGL-K_ny7tH217FzoPu.pdf

Because your engine is fourth design generation, the usual overhaul manual does not apply. You will need the late side-valve single cylinder manual, which is known by its Briggs part number of 270962.

I do not know of any reason why there would not be a market for the engine, so long as it was in good operating condition. As Bob said, if it has sat in that creek with water in the cylinder, it is only usable for spare parts. The same applies if it is in poor mechanical condition.

I'm always on the lookout for large engines, so there'd have to a market up that way too.

As far as a monetary return goes the engine might not be worth rebuilding (if it needs it) but the parts are definately worth something.

The whole no oil broken con rod thing, someone might want to go to the trouble of buying it for just the rod.

The electrics you could test easily, i would be inclined to do it after id taken the head off and checked the bore and valve clearances, but if it spins ok by hand, there probably little harm in cranking it over. Just for the starter you could get $40 or more if it works.
Same for the coil.

Because that is a synchro-balance engine, and a fair number of those spit the dummy when they get old, there are always people looking for full replacement engines in decent shape to get their ride-on mowers back into production. If it doesn't have water in it, there is a very good chance it will be at least moderately healthy. Needing new rings is fairly insignificant - if the balance system and bore are OK, that engine's a piece of gear people want.

So far as selling it for parts is concerned, the flo-jet carburetor and the starter/alternator alone are popular items.

hahaha, I've got one here, a 28B707 model, with a custom 37 piece conrod! Crap happens, the bloke who brought it in thought it could run with, what he admitted to, bugger all oil on the dipstick. Another Con Rod is all it needs, and a clean up of the big end journal!

Just a side issue here - as I said this motor was aquired because I was after the special double pulley attached to it. This pulley with its spacers measures 82.4mm high. The PTO on the B&S is 80.3mm long. The PTO on the new Honda GXV390 comeing next week is 79.5mm long (according to specs)

Will there be any problem bolting the pulley and spacer straight on the Honda - no hassles with pre-load or anything? Should linish the spacer down so total height of the pulley matches the length of the Honda PTO?

Picture please??? Picture of the pulley youve got would be appreciated. And another with the measurements marked on it.
Pully i have is only 2 and a bit inches deep. I will get some pics and meet you over in the other thread.

Repost in the thread about the slasher.

Best if its answered there.

Pictures in the other thread Link to thread