Heymow - Lawnmower Racing Forum

General => Coffee Shop => Topic started by: loggers gogert on March 04, 2020, 11:43:24 am

Title: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 04, 2020, 11:43:24 am
hi, my name is logan, i have a offroad mower, which i have many question for but will ask those later

i am building a homade go kart, and am using a B&S 6.5 hp engine, and i will use an 5 speed riding mower rear transmission

i would love to boost the power of this engine, does any body know of a racing crab i can get for this engine?
and i would also maybe like to remove the governor, if so, how do i do that? and if i do, are there any internal modification i should make to make it safer?
and last question about it, does anybody know of any performance kits for this? like maybe a kit that comes with aftermarket air filter, or exaughst and maybe pistons or camshaft?

thanks so much and i can't wait to hear your replies!

-logan
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 05, 2020, 11:13:00 am
is this website even active anymore????
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: BIG AL 202 on March 05, 2020, 11:39:12 am
YES! slow but yes. The 6.5 isn't really used in the lawnmower race world. If you are on facebook there are some minibike and go kart places that can help. For parts you can try EC carb, or ARC. Both can be found in the links section. These are good people with a lot of knowledge!
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: TomL on March 05, 2020, 08:10:44 pm
PA MIniPro mowers use the 196cc clone
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 06, 2020, 11:17:31 am
oh.........i think i forgot to say that my lawnmower already has an engine in it

but this 6.5 hp isn't going to be used for a mower, it will be used for a GOKART, i don't know if i stated that in my first post, sorry for the confusion
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 06, 2020, 11:20:39 am
but back to my question:

as i said i would like to remove the governor on that but i don't know how, and if i did remove it, are there any internal parts i should upgrade to make it safer?
and are there any performance kits for it out there that you guys know of?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 09, 2020, 12:27:30 pm
uuuuuuuhhhh......hello???????

did i say something that scared y'all off?????????????
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: BIG AL 202 on March 11, 2020, 04:46:20 pm
Tom, i'm not familiar with that class. Is it for kids?If so that's a great idea.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 12, 2020, 09:38:47 pm
eh-hem.... *cough*cough*


as i said i would like to remove the governor on that but i don't know how, and if i did remove it, are there any internal parts i should upgrade to make it safer?
and are there any performance kits for it out there that you guys know of?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: TomL on March 14, 2020, 09:09:21 am
Tom, i'm not familiar with that class. Is it for kids?If so that's a great idea.


Its no kids class. Our lap speeds are just less than 40mph, end of straights in the low to mid 40s.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 14, 2020, 10:48:53 pm
are you guys just ignoring me????
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: nic_hayes on March 16, 2020, 07:42:44 pm
This site is for sanctioned lawn mower racing builds with rules, not off-roading go karts. Plenty of other groups for that stuff.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 16, 2020, 09:30:18 pm
ahhh, okay, its only that I've seen MANY other threads on here with off topic conversations......

but how do you know that its for a gokart?
what if i told you it was for a racing mower?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: nic_hayes on March 17, 2020, 07:51:57 pm
You clearly said GOKART right here, lol.
oh.........i think i forgot to say that my lawnmower already has an engine in it

but this 6.5 hp isn't going to be used for a mower, it will be used for a GOKART, i don't know if i stated that in my first post, sorry for the confusion
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 18, 2020, 10:39:37 am
what if i was lying?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on March 18, 2020, 01:06:24 pm
Let’s start here. 

http://www.heymow.com/index.php/topic,2590.0.html

what if i was lying?

Then you won’t be here for long. 

What is your budget?    That will determine how far you can go.  Is it $5 or is it $5000.

Depending on budget you may be better off finding a different engine.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 19, 2020, 11:50:47 am
thank you.....and I'm sorry guys for my attitude as for i just haven't had any luck with other forums..
my budget is around 1000$, maybe more
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on March 19, 2020, 01:15:26 pm
Is this a horizontal OHV engine?   I’m not familiar with the smaller Briggs engines. 

Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 23, 2020, 10:13:36 am
yes it is
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on March 23, 2020, 01:39:19 pm
I'm not sure what is available for that engine.

If your removing governor you will need a billet flywheel and billet rod. 

Probably going to need to do something with the valve springs and retainers.

For more performance a better cam and Carb are next.

Although you can probably find a used built clone engine for less money.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 24, 2020, 12:17:12 pm
if heard people talking about clone engines...but what are they?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on March 24, 2020, 01:31:06 pm
A clone of a Honda engine.  Sold by retailers such as harbor freight.  All the Honda parts fit.   There are a lot of performance parts for the Honda.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 25, 2020, 12:14:45 pm
okay, for now I'm just going to forget about that little engine because i don't really want to do it anymore....
but.....i DO have an offroad mower that I'm building with a 16.5 oppy, what do you suggest i do to it ( internal mods) i don't want to make a ton of power as for i want to save some money, but i was thinking a flywheel of course, and maybe some billet rods? and removing the governor?
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on March 25, 2020, 09:05:47 pm
Flywheel and ride are a must if removing governor from an opposed twin.  Leave the rest stock and you will have cheap fun.   

If you only remove the governor you will shoot a rod through the block or die when the flywheel explodes.   
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: loggers gogert on March 26, 2020, 08:50:56 am
lol yeah, i know about the rod exploding out and flywheel coming apart, i had a buddy one time that was gonna remove the governor on his 300ish cc gokart and i was like
"NO, IT WILL FLY APART AND U WILL DIE!"
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: CedarHill on April 05, 2020, 07:21:14 pm
I got about 13 hp out of a 6.5 hp 212 cc predator engine with less than 6 bucks. I strait piped it, removed the governor, made a custom air filter, and jetted the carb. The thing shot 6 inch flames out the exhaust then blew up putting a hole in the crankcase. Don’t rev it under no load and I’d say your fine. The engine was a couple years old and ran hard. Also their only $99 at harbor freight. Just remember, more air flow = more power. One thing to watch with the small engines at high rpm is if the pressure release on the cam gets stuck. If this happens it will be really hard to pull on the starting cord and you just have to open up the crankcase and tap it to get it to move.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: CedarHill on April 05, 2020, 07:29:17 pm
Ive witnessed two engines exploding and the situations didn’t seem dangerous to me. Both times it just suddenly stopped there wasn’t any big explosion or anything flying in different directions. Both times the rod gave out at the crankshaft. Both highly modified 212 clones
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on April 06, 2020, 12:42:41 am
I got about 13 hp out of a 6.5 hp 212 cc predator engine with less than 6 bucks. I strait piped it, removed the governor, made a custom air filter, and jetted the carb. The thing shot 6 inch flames out the exhaust then blew up putting a hole in the crankcase. Don’t rev it under no load and I’d say your fine. The engine was a couple years old and ran hard. Also their only $99 at harbor freight. Just remember, more air flow = more power. One thing to watch with the small engines at high rpm is if the pressure release on the cam gets stuck. If this happens it will be really hard to pull on the starting cord and you just have to open up the crankcase and tap it to get it to move.

Dyno sheet?   

No way you double the horsepower by jetting the carb.   Flames out of exhaust is too rich and less horsepower. 

If you remove the governor you need a billet flywheel for safety. 
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: CedarHill on April 06, 2020, 08:59:51 am
I used a video on YouTube that tested different stages of modification on the predator 212 engines.
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: CedarHill on April 06, 2020, 09:07:53 am
This site show the different upgrade you can do to your predator 212 and other similar engines to get what they say is 26 hp. I did everything that didn't cost anything.
https://gokartsusa.com/Predator-212-Engine-Perfmance-Parts.aspx
Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: cycloneracer on April 06, 2020, 09:35:27 pm
That site states you need to replace the flywheel as well for safety.  Performance is the added benefit. 

No discussion of removing the governor without a billet flywheel. 

Most “free” modifications do not gain much performance.    Camshaft and valve train will yield the best gains.

Title: Re: what mods can i do to my B&S 6.5hp engine?
Post by: BIG AL 202 on April 09, 2020, 01:00:27 pm
To get that kinda power out of a 212 predator you WILL need to spend a lot of money. Those guys that get that kinda of power have a lot of billet and  expensive replacement billet heads.