5hp Briggs questions

[Wilson_Engine_Shop]

So i'm getting ready to clean up this old 5hp Briggs and get it running again after sitting out for a couple years. I'll be getting a new carb and inspecting everything inside. My main question is, what is this assembly under the tank? Is it governor related? Can i remove the governor and this thing and still have a good running engine? Its the original engine off my Carter bros. kart but its just going to be a spare for it.

The tank has quite a bit of rust in it but its still solid. I plan on pouring Evaporust or something equivalent in it to remove the rust and reuse the tank since new or used ones cost around $100. Any advise on this rebuild? My older brother originally "rebuilt" the motor in his Small Gas Engine class several years ago.

I also have no idea where the throttle cable is supposed to be hooked up either

 

[KartFab]

My advice is ditch the carb and tank completely, then remove the governor.

You can buy an adapter (or make one if you can weld) that allows you to run a slide carb like a pz22 on the Flathead.

 

[Beach Bum]

Here's what I have as far as the Throttle Hook Up and a picture.
This is not my Go-Kart though.

 

[Wilson_Engine_Shop]

Ah yes, it all makes sense now! Thanks! I need to clean the motor up real good to get a better look at things.

Do they sell an adapter to go to a slide carb? The vm22 would be my go to. Although its a little out of my budget set for this I like the idea Grant! I'm pretty good at welding but I only have a Chicago Electric flux core welder

Im not sure how the governor is setup but i'll do a little research on how to remove it

 

[Texan]

Ah yes, it all makes sense now! Thanks! I need to clean the motor up real good to get a better look at things.

Do they sell an adapter to go to a slide carb? The vm22 would be my go to. Although its a little out of my budget set for this I like the idea Grant! I'm pretty good at welding but I only have a Chicago Electric flux core welder

Im not sure how the governor is setup but i'll do a little research on how to remove it

Try a Tecumseh flathead Intake Manifold. They will bolt right in, and there are several configurations/versions.

 

[Wilson_Engine_Shop]

Okay. I'll look into that! Thanks! What do I do about the PCV system on the briggs?

 

[JTSpeedDemon]

Just unhook that 90 degree grommet to the carburetor! It's an EPA recycling tube, and it tends to screw with things.

And since I wasn't here earlier, YES that is part of the governor linkage. If you pull off the crankcase cover, you can simply pull the governor off the shaft with your fingers to remove it. You can remove the rest of the components, but I have found it's not necessary.

The simplest way to do a governor removal on a Briggs is to pull out the gear and reuse the throttle linkage. I decided to clock my governor arm a bit to get more throw, but I don't think it really needed it.

Or if you want to, you can put about $10 into it and get a snappier throttle, with a Raptor throttle: https://www.ombwarehouse.com/briggs-throttle-kit.html

The only reason I'm not using one is because it's for Pulsa-Jets and I have a Flo-Jet.


If you have any more questions feel free to ask, I have a complete service manual, it's just too big to upload.

 

[KartFab]

I found that I could run a 1/4” fuel line though the grommet and vent it to the ground. Zip ties the fuel line to the grommet. This is the clear/translucent colored type. Looks like you need a new breather grommet as well as yours is cracked.

 

[Wilson_Engine_Shop]

I found that I could run a 1/4” fuel line though the grommet and vent it to the ground. Zip ties the fuel line to the grommet. This is the clear/translucent colored type. Looks like you need a new breather grommet as well as yours is cracked.

I already found a set of grommets on Amazon. Thats another good idea with the fuel line and zipties

 

[Wilson_Engine_Shop]

Just unhook that 90 degree grommet to the carburetor! It's an EPA recycling tube, and it tends to screw with things.

And since I wasn't here earlier, YES that is part of the governor linkage. If you pull off the crankcase cover, you can simply pull the governor off the shaft with your fingers to remove it. You can remove the rest of the components, but I have found it's not necessary.

The simplest way to do a governor removal on a Briggs is to pull out the gear and reuse the throttle linkage. I decided to clock my governor arm a bit to get more throw, but I don't think it really needed it.

Or if you want to, you can put about $10 into it and get a snappier throttle, with a Raptor throttle: https://www.ombwarehouse.com/briggs-throttle-kit.html

The only reason I'm not using one is because it's for Pulsa-Jets and I have a Flo-Jet.


If you have any more questions feel free to ask, I have a complete service manual, it's just too big to upload.

So whats the difference between a pulsa-jet and a Flo-jet? Can you tell which one I have?

 

[JTSpeedDemon]

Pulsa-Jets are diaphragm carbs. I can see in post #6 in the second pic the diaphragm housing right above the EPA tube. Pulsa-Jets are very common and versatile.

Vacu-Jets are vacuum carbs that draw directly from the tank with no diaphragm. However, while they are very simple and reliable(and very common on <5 HP engines), they can suck air if gas is low enough while on a slope.

Both Vacu-Jets and Pulsa-Jets are tank mounted.

Flo-Jets are the least common, except for the 90s style flatheads(like yours) and big blocks.
Flo-Jet has been used to refer to multiple designs of carburetors in the past. Most however are like the one on my 5 HP HiPo flathead.

The kind I am referring to is a two piece float type updraft carburetor with a remote fuel tank.
Flo-Jets are a little cantankerous if not cared for right. The carburetor body mating surfaces can warp, causing leaking. If water gets into the float bowl and freezes, the hollow brass float will crush. The brass float also makes it unsuitable for any forced induction applications, with the exception of draw through setups.

Flo-Jets are, however, designed to last. Virtually every part is replaceable, including the venturi(only on some, like mine) and throttle shaft bushings! I've even heard of Flo-Jets outlasting the engines they're on!


Phew, that was a long writeup!

 

[Wilson_Engine_Shop]

I found a couple of Tecumseh intakes but idk what the shape of the intake port is so i can find the right one. I watched KartFabs Bronda video series and learned a lot, but i'm not as good at fabricating.

 

[Wilson_Engine_Shop]

I finally found a Briggs to Mikuni intake but now i'm wondering if I could use a honda carb with this intake since I have a spare honda carb laying around instead of a chikuni which is a little pricey for me

 

[KartFab]

You can get a slide carb like a pz20 for $13 on eBay

 

[Wilson_Engine_Shop]

Would a pz20 be enough to feed the 5hp briggs?

 

[JTSpeedDemon]

Given that the stock carb is like 19mm in. inner diameter, yep!

22mm is ideal for non or mildly head-worked Briggs, but 20mm will do the job just fine.

 

[Wilson_Engine_Shop]

Alright, cool! I was actually planning on porting the head like KartFab did in his Bronda series. I'll see if I can get a PZ22 on Ebay if its cheap like the PZ20

 

[Wilson_Engine_Shop]

This looks like it'll fit the bill