Thread: Project Tiny Mighty, modding a Briggs & Stratton engine

I acquired a "broken" power washer, really hard to get it started but it ran. The compressor was leaking and wouldn't build any real pressure... So I took it apart and found that the seals on the compressor were completely shot, and it made a clunky noise when I shook it.

The engine on it is a 4 hp B&S Quattro, and the pull start clutch is shot. So I decided I want to build this little engine into a beast, and drop it into a little go-kart.

Here's some pics:

































I'm planning on orienting it vertically, porting and polishing a good amount (practice, lol), modding the carburetor/intake manifold, putting a flywheel and electronic ignition system on it, with an electric starter. Plus the all-important crankshaft pulley, to run a small alternator for a 12v system. All I need is some advice on the carburetor mods and how to pull the stator off of the crankshaft.

Should be a fun little project, and I'm hoping to hit ~10 hp, with a 150lb go-kart frame that should get me into the 60-70 MPH range... lol

Bearing puller and if need be some heat on the stator, not the shaft, should remove it.

how you plan to run vertical shaft and power the go cart? most run a horizontal crank. as far as porting it. if that carb dont have mix screws, hi and low mix screws that is, dont, cause you cant tune it. looks like a plastic carb too? and a plastic cam! wtf?

i used to work at a mower shop, we had the crazy guy there. he machined the head for a second spark plug added a coil for it and ran a monster carb. it was fast right up till the rod blew lol

I've got a plan for a custom diff... but I've seen some ways of reorienting it for horizontal, cutting new oil channels and filling the old ones, with a custom oil flinger.

I'm looking at different carbs, there aren't any adjusting screws on it at all. plus it looks to be integral with the gas tank, and that's an issue.

The cam though... I was surprised when I saw that it was plastic. lol I might get a 5hp steel one, dimensions are the same... Plus I can do a custom grind on a steel one, not so much on a plastic one.

Originally Posted by Scottydoggs

i used to work at a mower shop, we had the crazy guy there. he machined the head for a second spark plug added a coil for it and ran a monster carb. it was fast right up till the rod blew lol

Damn I don't remember doing that but it sounds like something I would do

Put some singh grooves into the head!

Originally Posted by ItHurtz

Put some singh grooves into the head!

You first! Lol

It's tempting...

It is tempting, my heads are still looking at me, waiting.......small engine wise I wouldnt think twice about it!

I'm still looking at carbs and new gaskets, I'll have plenty of time. Lol

I've also got to look at a custom intake manifold, and whether I want to do some form of transmission...

Lots to do. Lol

throw it in the garbage, buy a HF 6.5 predator, and cam it, then atleast one thing you drive will have balls

Or spend that 200 bucks on something else? Lol

all the cool things>Old pos motor
https://www.ombwarehouse.com/Perform...c-Racing-Parts

my gokart has a stock 6.5 predator

Unless that price drops to $free.99, this one will still be cheaper, and make just about the same hp when I'm done with it.

Plus, I need practice with the grinder.

No I/C Briggs. ...no care.
Old> new

I wish it was an I/C series...

But it'll work for what I need.

Originally Posted by ItHurtz

all the cool things>Old pos motor
https://www.ombwarehouse.com/Perform...c-Racing-Parts

my gokart has a stock 6.5 predator

But is it a Hemi?

Probably not, considering the frown.

No hemi, I have a 17horse briggs IC in the work mower

And your pos 4hp will never compare to a built and cammed 6.5 pred!

Na guy problems!

I'll throw a turbo on it! Don't tempt me!

In reality though, the generators we use at work have really tiny turbos... Smaller than my fist kind of tiny.

do it. turbo and a ic between the roll cage. best get a stronger rod for it too. they break in stock form.