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Briggs & Stratton 5S & Model Y help

Cnew

Registered
Hello,
I’m new to the forum and new to these older Briggs engines. I’m guessing these questions have been asked before but I could use a little advice. Is it good to add lead additive to today’s fuel? I have access to non-oxy at the local station. The manual calls for SAE 20 oil, is SAE 30 ok or should I look harder for specialty oil? What is the best way to remove the flywheel without damaging it or the crankshaft? It looks like the magneto coils are no longer available, does anyone know of a good replacement? Thank you for sharing your expertise!
 

ulgydog56

Registered
use a hermonic wheel puller for the flywheel, they still sell dead 20 wt oil...low compression engines can use leadfree gas,if u want to use instead of lead additive it wouldnot hurt..autozone
 

Cnew

Registered
Thanks for the suggestions. Normally I use a harmonic balancer for flywheels but the flywheel on the 5S doesn’t have any threaded holes on each side if the crankshaft to mount the puller. Hoping there are some other tricks. I have a similar situation on an old 4hp Kohler.
 

FlJim

Registered
First off, as I recall, the retaining nuts are left hand threaded. On removing the flywheel, I have removed many of them by applying pressure (don't be too aggressive) under the flywheel and with the nut screwed almost all the way down, strike the nut sharply and squarely on the end of the crankshaft. You need more than a tap with the hammer to break it loose and likely will have to hit it more than once. Good luck!
 

Turbo

Subscriber
Last Subscription Date
07/12/2019
I second what FLJIM says. On the 5s thread the nut back on and strike the end of the crankshaft while applying pressure to the flywheel with your other hand. The Y is different as it is not a taper shaft. It uses a strait shaft with a bolt through the center to secure. They can be stubborn. I lock the crank with a pipe wrench on the pto end then try to spin the flywheel off. These engines are very common and parts are plentiful. Finding a good coil is no problem. I think I have a dozen or more of each coil laying around. I don't live too far from you in New Prague. PM me if you need any info or parts.
 

Junkologist

Subscriber
Last Subscription Date
12/28/2019
Be sure to use a brass, copper, or lead hammer when striking the end of the crankshaft. A steel hammer will damage it.
 

Ogrebeast64

Registered
The older engines like the 5s and the Y do not have the hardened valve seats, so I would recommend using the lead substitute to keep from damaging the seats. I've got an old Model 8 (manufactured in 1951) I restored, and only use the non ethanol in it with lead substitute.
 

Cnew

Registered
Thank you all for the great advice and tips. I’m anxious to give these a try and see what happens.

Turbo,
I may take you up on the parts offer once I get deeper into this engine and know what’s going on with it. If you’re interested I ugh thanks be interested in buying a coil from you just to have it on hand. I haven’t tried to fire the Y yet, I need to get a gas tank for it. I think it has spark. It doesn’t have the kick lever, looks like someone tried to convert it to a rope start and I’m actually thinking the pulley they used is backwards. Should the model Y engine rotate clockwise or counterclockwise?

This is an addictive hobby! Y’all are great!
 

Andrew Mackey

Moderator
Last Subscription Date
05/14/2017
Back when these engines were built, tetra ethyl lead was still not common in gas. Unleaded won't hurt, as these are relatively low compression (5:1), low speed (under 3000 RPM) engines. They are not high compression auto engines! No alky fuel is good, I would run high test if you use alcholized gas. SAE 20 is available from Tractor Supply, and some auto stores. You may have to ask for it if you do not see it on the shelves. SAE 30 Ok for most, if above 40F. Below that, you must use the SAE 20 or even 10W-30. DO not use SAE 30 in the WI with the oil pump - it is too thick for the pump to operate properly. Don't use the 10-30 in the summer - too thin!
 

Cnew

Registered
Thank you Turbo, glad I asked- the pulley that is on the engine now definitely has it turning counterclockwise.
 

Ken Karrow

Subscriber
Last Subscription Date
12/10/2019
20 weight should be at any decent farm supply if you do not have TSC. Back in the day we used to go to the marina to get marine white gas for mowers. Dad claimed run cleaner in the little briggs. I believe it was no lead, octane was low enough that a stock '48 Chevy would knock on it when pulled at low rpm.
 

Andrew Mackey

Moderator
Last Subscription Date
05/14/2017
'White Gas' is like Colemens fuel - only about 50 octane. It does burn clean though. As you found out, it will knock if heavily loaded in an engine. Lucky you didn't hole a piston! Most marine engines were cooled directly from the lake or river water that was available, which made them run very cool - no thermostats like in a car. You could get away with a lower octane in a cold running engine - it wouldn't get hot enough to knock! Also, marine engines almost never get to be heavily loaded like a car engine, unless they were mated to a propeller that was too large for the engine.
 

Cnew

Registered
Re: Briggs & Stratton Model Y help

Once a Model Y is running, what is the proper way to shut it down? My engine doesn’t have any sort of kill switch or tab that you touch to the spark plug. I plugged the air intake with my finger which worked but that doesn’t seem like a good thing for the engine.
 

Cnew

Registered
If you all are able to get SAE 20 in your area you might want to stock up. Definitely not available where I’m at. I checked TSC as well. Only straight grade they can get is SAE 30. Other than that it’s multi weight or synthetics.
 
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