Briggs and Stratton Build

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
It’s cool to know so many love these old 4t Briggs on here too, I figured this build wouldn’t get much, if any interest.

Are you guys part of any other forum dedicated to 4t stationary engines like this that you can recommend?
 
The Old Tecumsehs were great engines also they got a bad rap because the carbs were a bit tough to figure out.The later OHV ones had seat coming loose issues .
The Kohler KT17 series 1 engines suffered from oil starvation when mowing on hilly terrain.These KT17s created a giant black mark on John Deeres reputation when they failed early.TheKT series two engines were super as good as Onan in my books.
Kash
 
The Old Tecumsehs were great engines also they got a bad rap because the carbs were a bit tough to figure out.The later OHV ones had seat coming loose issues .
The Kohler KT17 series 1 engines suffered from oil starvation when mowing on hilly terrain.These KT17s created a giant black mark on John Deeres reputation when they failed early.TheKT series two engines were super as good as Onan in my books.
Kash
Never cared for the old onans (like sears suburban era) they would run great till they wouldn't. Then if you let the carb get crud in it, it was a $400.00 bill for a new carb. Couldn't adapt a Briggs or other carb to them. Basically replaced them all with magnum engines when they started giving grief. At least the newer ones ran great and didn't cost an arm and leg to repair.
 
I really Like the Onans except for the insane cost of replacement parts. I have two Sears with Onans you have to really watch the valve clearances super simple crude carbs I always use an electric pump on the Onans .It makes for instant starts.
Kash
 
I really Like the Onans except for the insane cost of replacement parts. I have two Sears with Onans you have to really watch the valve clearances super simple crude carbs I always use an electric pump on the Onans .It makes for instant starts.
Kash
Yes the integrated fuel pumps were issues with them. They were runners when they worked right. Have to give them that much.
 
Well I sold my green Briggs edger just now which is great. The owner who generously gave it to me said he was about to drop it off the dump before I caught him. It needed a good clean of the carb as the main jet was blocked solid, valves adjusted and it ran beautifully. While I was in there I cleaned the piston, valves, did an oil change, cleaned the plug, tuned it to manual specs, and other bits. Glad it’s gone to a new home. I did offer it to the previous owner for free, but he had brought another one already and said It was mine. I was able to cover my costs for cleaning sprays, oil and a spring and can still take my partner out for a weekend away. Happy days.

Shes slowly coming around to the idea that having stinky old equipment around the back garden / shed can be beneficial to her!

724FEECB-C850-41C0-9221-DABE9291B9D4.jpegA1D23636-5BE1-4FD3-95B4-94C8F4B54507.jpeg
 
I put a facet fuel pump on my wheel horse and it’s been great. I have it wired up with a fused toggle switch (I didn’t get power off the ignition but should have). No problems but I have to remember to shut the switch off. Usually I shut the pump off and then the ignition. Made it a habit.
 
Hey guys, a little update on this engine. Because it’s never going to be used on a piece of equipment, and I only ever want it to chug along slowly whenever I start it for fun, I decided to disconnect the govenor linkage as the butterfly would continuously flutter at idle and it was never stable.

I then put my own return spring on and here is the result. It will idle down to 700rpm, but it’s happiest at 1200.


EDIT

I decided to take the needle and jet apart to confirm my thinking that the needle restricts only the H side. I was surprised to see the jet is before both drilling’s and feeds both.

Turns out that the needle doesn’t fully seal the jet and so even closed, when the engine is at low RPM, it still gets more than enough fuel. I connected up the mityvac to the jet and pressed the needle against the drilling and it bled.

The two drilling’s after the jet are either side of the butterfly. The small drilling is to the right and past the butterfly and the large is to the left behind the butterfly.

So this is what I’m thinking happens at idle -
Any advice or correction is appreciated.


Air is draw down the venturi depicted as the blue arrow, which comes into the large drilling orifice and then show as blue dots.

At the same time, vacuum draws the fuel up through the threaded hole with the red arrow pointing to it, past the jet (not pictured here) and mixes with air depicted with red dots.

That combination then flows through the smaller drilling (shown with blue and red arrows on top of each other) and actually bypasses the butterfly to then go into the intake?99A0DCA8-A3AF-4FFE-842B-F824DDE5867D.jpeg
 
Hey guys, a little update on this engine. Because it’s never going to be used on a piece of equipment, and I only ever want it to chug along slowly whenever I start it for fun, I decided to disconnect the govenor linkage as the butterfly would continuously flutter at idle and it was never stable.

I then put my own return spring on and here is the result. It will idle down to 700rpm, but it’s happiest at 1200.

Took this video for a mate, but wanted to share it with you all too.

That steady slow idle is really beautiful.



And here is a video comparing before and after removing the govenor and re tuning it.


You need to put it on a mini bike!
 
Back
Top