i'm currently rebuilding a briggs 3 horse:hammer:, and am thinking of putting on a 22mm mikuni carb instead of the old pulsa-jet style. i've heard that this will increase performance. does this really give me more power, and besides boring it out and port and polish, does anybody know any other mods to get the max out of my old briggs 3 horse? also what are some good websites for getting high performance parts for my briggs motors. thanks!:thumbsup:
Anything is better than a pulse jet.. :hammer: A mikuni would be a hell of a carburetion improvement but it's gotta be about the right bore to match your intake port, then you'll need to get a bunch of different main jets so you can get it jetted right.. Another good way to get more response and top end is advance the flywheel to advance your spark.. You can also cut the end of the valve stem off just a slight bit over what is called for and do away with the compression release in the stock cam to build torque.. The 3 horse Briggs isn't a torque monster but if ya mess around with them they will go like their ass is on fire..
oh... and a big pipe never hurt anything either..
oh... and a big pipe never hurt anything either..
It's probably not worth the price of high dollar after market stuff for a 3 horse.. Ya might find some used goodies on Evilbay cheap.. :shrug:
Advancing spark, the easiest way is just file off some of your flywheel key.. You can get them specifically made for advancement.. Theres probably a thread on how to do all that with pics and stuff I'd guess..
Carburetor I'd just run a Tecumseh adjustable... SOOOooooooo damn nice for everyday use and dependability.. Or possibly a Tillotson.. anything with a high and low speed fuel adjustment screw.. I like Tecumseh carbs myself... You should just bring the motor to me next time you're traveling by.. :wink:
Advancing spark, the easiest way is just file off some of your flywheel key.. You can get them specifically made for advancement.. Theres probably a thread on how to do all that with pics and stuff I'd guess..
Carburetor I'd just run a Tecumseh adjustable... SOOOooooooo damn nice for everyday use and dependability.. Or possibly a Tillotson.. anything with a high and low speed fuel adjustment screw.. I like Tecumseh carbs myself... You should just bring the motor to me next time you're traveling by.. :wink:
i may just do that or i could ship it to you with the parts and you can work your majic on it! i have another 3 horse that i dont have all the guts to i could have ya do sum stuff to it if ya want. throw me a price and i'll let ya go to town. i will search for that thread on the advancing the flywheel. i know that little 3 horse can haul if i get it done just right!!
ahhhhh..... i see. i have a 5 horse flatty i'm thinking of tearing down and rebuilding after reading that "awsome guide to modding briggs 5hp flatheads". i tell ya that is very informative. but back to the three horse, i think i may just do what i can and call it that. seems to be everywhere i look i can't find any mod parts for 3 horse, but a crapload for 5 horse's. so be ready kid, i may be asking a ton of questions to get the flatty running like a raped ape!!!
The "Freak" has given you the best suggestions.
The more compression you get out of it the better. Cut the head until the valves are just touching the head with no gasket.
Here are a few more "Rhovis" suggestions:
ut:
A slight blend at the top of the cylinder on the valve side only that extends down to just above the ring travel will help gas flow. Back cut the valves. Take the block to a machine shop and have them hone the cylinder so it's ROUND.
ROUND
ROUND
Round with in a "tenth" (.0001")
Then get .005 oversize rings and file fit the end clearance. Get a new stock rod and new piston.
Remove the oil dipper from the rod and knife edge the crank. Polish any casting flaw off the parting line of the rod and fit the bearing clearance to a round journal. If you really want to get carried away have the machine shop gas port the top ring land. Take a die grinder and remove metal from under the piston to both lighten it and to create a heat dam. Paint the inside of the cylinder head with high temperature paint. Better yet have the head ceramic coated to retain heat. You can also remove every other fin on the head to help build heat.Install a sintered metal filter in the valve spring pocket to keep oil in the crank case.
And that's just touching the surface. Cam work and ignition work will also yield results as well. Don't let anyone tell you these little things can't be made to perform!!!
Oh and don't forget to have the crank balanced by an shop that knowns how to calculate the bob weight.
Have fun and be safe is the best advice Rhovis can give ya.
The more compression you get out of it the better. Cut the head until the valves are just touching the head with no gasket.
Here are a few more "Rhovis" suggestions:
ut:A slight blend at the top of the cylinder on the valve side only that extends down to just above the ring travel will help gas flow. Back cut the valves. Take the block to a machine shop and have them hone the cylinder so it's ROUND.
ROUND
ROUND
Round with in a "tenth" (.0001")
Then get .005 oversize rings and file fit the end clearance. Get a new stock rod and new piston.
Remove the oil dipper from the rod and knife edge the crank. Polish any casting flaw off the parting line of the rod and fit the bearing clearance to a round journal. If you really want to get carried away have the machine shop gas port the top ring land. Take a die grinder and remove metal from under the piston to both lighten it and to create a heat dam. Paint the inside of the cylinder head with high temperature paint. Better yet have the head ceramic coated to retain heat. You can also remove every other fin on the head to help build heat.Install a sintered metal filter in the valve spring pocket to keep oil in the crank case.
And that's just touching the surface. Cam work and ignition work will also yield results as well. Don't let anyone tell you these little things can't be made to perform!!!
Oh and don't forget to have the crank balanced by an shop that knowns how to calculate the bob weight.
Have fun and be safe is the best advice Rhovis can give ya.
The "Freak" has given you the best suggestions.
The more compression you get out of it the better. Cut the head until the valves are just touching the head with no gasket.
Here are a few more "Rhovis" suggestions:ut:
A slight blend at the top of the cylinder on the valve side only that extends down to just above the ring travel will help gas flow. Back cut the valves. Take the block to a machine shop and have them hone the cylinder so it's ROUND.
ROUND
ROUND
Round with in a "tenth" (.0001")
Then get .005 oversize rings and file fit the end clearance. Get a new stock rod and new piston.
Remove the oil dipper from the rod and knife edge the crank. Polish any casting flaw off the parting line of the rod and fit the bearing clearance to a round journal. If you really want to get carried away have the machine shop gas port the top ring land. Take a die grinder and remove metal from under the piston to both lighten it and to create a heat dam. Paint the inside of the cylinder head with high temperature paint. Better yet have the head ceramic coated to retain heat. You can also remove every other fin on the head to help build heat.Install a sintered metal filter in the valve spring pocket to keep oil in the crank case.
And that's just touching the surface. Cam work and ignition work will also yield results as well. Don't let anyone tell you these little things can't be made to perform!!!
Oh and don't forget to have the crank balanced by an shop that knowns how to calculate the bob weight.
Have fun and be safe is the best advice Rhovis can give ya.
The more compression you get out of it the better. Cut the head until the valves are just touching the head with no gasket.
Here are a few more "Rhovis" suggestions:
ut:A slight blend at the top of the cylinder on the valve side only that extends down to just above the ring travel will help gas flow. Back cut the valves. Take the block to a machine shop and have them hone the cylinder so it's ROUND.
ROUND
ROUND
Round with in a "tenth" (.0001")
Then get .005 oversize rings and file fit the end clearance. Get a new stock rod and new piston.
Remove the oil dipper from the rod and knife edge the crank. Polish any casting flaw off the parting line of the rod and fit the bearing clearance to a round journal. If you really want to get carried away have the machine shop gas port the top ring land. Take a die grinder and remove metal from under the piston to both lighten it and to create a heat dam. Paint the inside of the cylinder head with high temperature paint. Better yet have the head ceramic coated to retain heat. You can also remove every other fin on the head to help build heat.Install a sintered metal filter in the valve spring pocket to keep oil in the crank case.
And that's just touching the surface. Cam work and ignition work will also yield results as well. Don't let anyone tell you these little things can't be made to perform!!!
Oh and don't forget to have the crank balanced by an shop that knowns how to calculate the bob weight.
Have fun and be safe is the best advice Rhovis can give ya.
wow!!! that is alot! and i got to be honest and say i understood about an 1/16" of that!! like i said i'm just starting out messing with small engines and i am trying to learn as much as can but i think i need to take some baby steps first. i'm guessing first thing i should do is find a machine shop and see what and how much it will cost to begin with. i'm not sure if i have any in my area but i will look. second i'm guessing is buying new(better)parts. this is my first rebuild and i'm not looking to spend a fortune as i am going to rebuild my 5horse flatty next and would rathr spend the extra money there. so this may sound dumb, but what is my cheapest route to go and how much horsepower can i get out of this 3 horse without breaking my wallet? typically i would want to get it to about 6-8 hp if possible, running 101 octane that is. he3lp! help! help!