Rebuilding an old Briggs: lots of questions! Father/son project!

[BubbyJ]

I have a Briggs and Stratton 4hp 187cc engine. It was pulled off of an old wood and leaf chipper. I'm unsure of its age, but I'd venture to guess that it's from between 1970-1980. Could be either side of that by a decade too lol, I honestly don't know. The model number is 112292 0707. I'm not sure if that helps anything, but all I've found is the operating manual online for it. I'm guessing it's pretty old just because it's only 4hp with almost 200cc. That's a pretty low number for an engine that size.

So here's the story...

I've been building automobile engines for the last 25 years, specializing in blueprinted "stock" engines from the 1960s and early 70s. So I don't really need much help in terms of rebuilding this thing. My 11 year old son is following in my footsteps and learning so much so fast that it's scary. He wants his own small block ford engine to build. I dug this old motor up recently for him to strip down and rebuild. He has a gokart frame that he wants to test it out on when we are done. So what I do need help with is this:

-where can I find a parts interchange list?
-suppose I wanted to install a more aggressive camshaft, where would I find the type of camshaft that's made for this engine? I'm assuming not all BS engines use the same cam type. Correct? Is there's a series or an engine design name for this motor that would allow me to identify parts better? For instance, small block Chevy. Pretty much any sbc part will fit any sbc engine (with exceptions). Same goes for 385 series Ford's. Or big block Pontiacs. Or FE engines.

So.. what am I looking for as I order a few parts for this engine, so that I know what I'm getting is correct for the model.

Thanks so much. This means the world to us. He's an incredible kid with big dreams and strong desire to learn with tons of motivation in action. During this crisis we find ourselves in, family means more to me than ever before. Im hoping that a couple of weeks from now, I'll have a 7-8hp engine for this kid to drifft around the yard in.

I see tons of parts for Briggs motors. Cams, billet cranks, high compression pistons, ported heads, straight exhaust, adjustable timing, etc. I had no clue that this world existed until the last few days.

If I'm in the wrong forum for these type of questions, can someone please direct to to where I can find the right people?

God bless yall. Stay safe please.

 

[Rivets]

Here is a service manual which should help you out. The second site is a parts breakdown for your engine. If you post the last set of numbers off the shroud we can tell you the year of manufacture. Most parts will be available at your local repair shop, but may have to be ordered. If you are someone who does their shopping online, I recommend Jacks Small Engine. Being a retired small engine instructor I’m always glad to see people like you teaching the younger generation, as I’ve had the opportunity to rebuild this type of engine with hundreds of students. Come back with any questions and the techs here will be glad to help.
Good Luck and stay healthy.

Google Drive: Sign-in

Access Google Drive with a Google account (for personal use) or Google Workspace account (for business use).

docs.google.com

https://shop.briggsandstratton.com/pages/parts-lookup#

Parts Lookup - Exploded Diagrams for Outdoor Power Equipment

Parts Lookup from Jacks Small Engines. We have labeled, interactive, exploded diagrams of power equipment from many of the top manufacturers. Free to use.

www.jackssmallengines.com

 

[logert gogert]

where would I find the type of camshaft that's made for this engine?

i was at the point one time where your son is. i wanted to put one of my 6.5 hp B&S engines on a gokart frame i had laying around, and i wanted to get some parts for it, ( billet flywheel & rods ) and i found a few parts, but not as many as you would think....
but if any body were to have any performance parts for that engine i have to say it would either be:
arc racing: ARCRacing.com | ARC Racing | High Performance Engine Parts‎Ad·www.arcracing.com/Engine/Parts‎(877) 210-7019
gopowersports: https://www.gopowersports.com/front-page
or precision cams: Precision Cams Homewww.precisioncams.com


or if you want to be on a forum where people do that stuff to small engines all the time ( the websites kind of like this its just....different..i can't really explain it ), I'm also a member on the website.
heres the link : https://www.atltf.com/forum
all you have to do is sign in ( like your did with this website ), then create a thread on the questions you have, and then wait for responses.

 

[Rivets]

Buddy, I see that you have started two different threads with the same issue. This will get very confusing and if possible delete one thread. If you can’t delete, pick one to work through and post on the other thread that you will not be using it. Thank you.

 

[Hammermechanicman]

You would probably be better off getting a decent 5hp briggs engine to "hop up" the 13xxxx series engines were used for years in go cart racing sanctioned by WKA. There were many classes from stock to wild alcohol burners. Now the Honda clones are the thing to run. There are lots of speed parts floating around for them, especially cams. Speed parts for the 4hp will be non existant unless they interchange with the 5hp. In another lifetime i used to build 5hp race motors. The other way to go could be getting a Harbor Freight Predator motor. There are speed parts available for them. A word to the wise. If you plan to disable the govenor and over rev the engine and the motor has a mechanical govenor and not an air vane govenor crak the crankcase and remove the govenor gear. If you don't the plastic gear will let go and when a metal weight gets in the gears it will blow the engine. If you plan to stay with the 4hp block you can mill the head, grind the easy spin bump off the cam, if the engine has a Magnetron ignition advance the timing by a third to half a key. Be sure to lube the shaft in the starter ratchet. Good luck with the young mechanic.

 

[logert gogert]

Now the Honda clones are the thing to run. There are lots of speed parts floating around for them, especially cams.

yup, he's right, there are so many parts out there for it.
we have a 212cc predator clone that were building, got a stage one intake and exaughst kit, billet rods, slightly bigger valves, reading cam, no gov, billet flywheel, genuine mikuni carb :3
thing has like 15hp, does like 7-8k RPM, does like 65mph, and will burn rubber with racing tires at 3/4 throttle XD
and we run it a bit rich so it shoots flames XD

 

[Rivets]

Logert, I’ve got a few questions about your build. What is a billet rod and flywheel? Second, when you replaced the cam did you replace valve springs as recommended? How did you use oversized valves and why? What did you use to measure speed and RPMs? Where did you purchase racing tires and on what size? Finally, what websites did you read to get this info from and how much did it cost you? Just like Trump I’m “fact checking you” as I doubt you have built anything like you are describing. You say your building one now, but it goes 65 mph, burn rubber, and throws flames. If you’re in the process how do you know this at this point? If this is really true, you’ve been lying to us in your early posts, where you don’t know how a governor works, carb linkages, removing wheels, carb knowledge, etc. Remember when you started a thread about how to make your lawn tractor go faster? Maybe you should read and follow your own signature.

 

[Hammermechanicman]

Logert, I’ve got a few questions about your build. What is a billet rod and flywheel? Second, when you replaced the cam did you replace valve springs as recommended? How did you use oversized valves and why? What did you use to measure speed and RPMs? Where did you purchase racing tires and on what size? Finally, what websites did you read to get this info from and how much did it cost you? Just like Trump I’m “fact checking you” as I doubt you have built anything like you are describing. You say your building one now, but it goes 65 mph, burn rubber, and throws flames. If you’re in the process how do you know this at this point? If this is really true, you’ve been lying to us in your early posts, where you don’t know how a governor works, carb linkages, removing wheels, carb knowledge, etc. Remember when you started a thread about how to make your lawn tractor go faster? Maybe you should read and follow your own signature.

BAM!

 

[logert gogert]

Logert, I’ve got a few questions about your build. What is a billet rod and flywheel? Second, when you replaced the cam did you replace valve springs as recommended? How did you use oversized valves and why? What did you use to measure speed and RPMs? Where did you purchase racing tires and on what size? Finally, what websites did you read to get this info from and how much did it cost you? Just like Trump I’m “fact checking you” as I doubt you have built anything like you are describing. You say your building one now, but it goes 65 mph, burn rubber, and throws flames. If you’re in the process how do you know this at this point? If this is really true, you’ve been lying to us in your early posts, where you don’t know how a governor works, carb linkages, removing wheels, carb knowledge, etc. Remember when you started a thread about how to make your lawn tractor go faster? Maybe you should read and follow your own signature.

alrighty...well, first of all, i didn't build the engine, my uncle did, he races go karts.
but i did remove gov myself. install the carb, restored the kart chassis ( bought it used ) put on the tires ( dunlop 10 in. ) , change oil, spark plug etc. and a performance coil. and did quite a few other things myself
and yes, i have 22lb springs, but yes...i will admit, that i lied about having bigger valves.
what did i use to measure RPM and speed... uhhhh, a tach and a GPS speedometer
and i didn't purchase my tires got em from my uncle.
and no i haven't been lying to you, and your right i still don't really know EXACTLY how a carb works, but i never said i didn't know how governor works, and i also never said i didn't know how to remove tires, just because i was asking for some tips and tricks on how to get a STUCK RUSTED ON rim off an axle docent mean i can't change tires.
and your really, really gonna ask me what rods and flywheel are?
and last but not least " what websites did i get my stuff from".......... did you even read post #3

 

[logert gogert]

alrighty...well, first of all, i didn't build the engine, my uncle did, he races go karts.
but i did remove gov myself. install the carb, restored the kart chassis ( bought it used ) put on the tires ( dunlop 10 in. ) , change oil, spark plug etc. and a performance coil. and did quite a few other things myself
and yes, i have 22lb springs, but yes...i will admit, that i lied about having bigger valves.
what did i use to measure RPM and speed... uhhhh, a tach and a GPS speedometer
and i didn't purchase my tires got em from my uncle.
and no i haven't been lying to you, and your right i still don't really know EXACTLY how a carb works, but i never said i didn't know how governor works, and i also never said i didn't know how to remove tires, just because i was asking for some tips and tricks on how to get a STUCK RUSTED ON rim off an axle docent mean i can't change tires.
and your really, really gonna ask me what rods and flywheel are?
and last but not least " what websites did i get my stuff from".......... did you even read post #3

BAM!