How to make more from a 2hp
- Thread starter wexplorew
- Start date
-internal/external governor delete
-lighten camshaft
add duration/lift <<crank grinding needed for more cam.
-port/no polish
-shave eyebrows
-stock head-gasket
-header
-intake/carburetor
-billet flywheel 30* timing advance
-electronic ignition coil with 8mm upgrade wire... My preference is streetfire wires to upgrade the coil wire.
It was gutless still. But I could not rev it high enough with a stock rod to break it. Had this modded 3hp on the trike and it was the best running 3hp engine I have ever seen after removing the mikuni and modding the stock tank carburetor.. It took so long to wind up so once it did I just kept it there just expecting the rod to chunk.. it never did.
-lighten camshaft
add duration/lift <<crank grinding needed for more cam.
-port/no polish
-shave eyebrows
-stock head-gasket
-header
-intake/carburetor
-billet flywheel 30* timing advance
-electronic ignition coil with 8mm upgrade wire... My preference is streetfire wires to upgrade the coil wire.
It was gutless still. But I could not rev it high enough with a stock rod to break it. Had this modded 3hp on the trike and it was the best running 3hp engine I have ever seen after removing the mikuni and modding the stock tank carburetor.. It took so long to wind up so once it did I just kept it there just expecting the rod to chunk.. it never did.
You can get some power from swapping the side cover to a ball bearing side cover and install a ball bearing on the crank. Most of the places these engines are installed there is a large side load on the crank by a belt or chain, the ball bearing will reduce the friction losses considerably.
BS 2hp with the stock crank has pretty low compression, be careful about removing too much metal under the head (eyebrows and such). Just rounding the edge of the cylinder bore in the area not covered by the head gasket (stay above the top ring) about 1/16-1/8 radius will provide improved flow in and out of the cylinder without affecting compression.
Clean up the exhaust port, removing all sharp edges and make sure the inlet end of the exhaust is flared internally to reduce turbulence going out or the port.
Do the same to the intake port but use some liquid steel or similar to fill the large square corners in the bottom side of the port, you goal is to try to maintain the same size opening all the way through the port and have smooth (not polished) surfaces all the way from the carb to the valve.
Polish the heads of your valves (they are part of the combustion chamber)
For stock looks but improved power, install a pulsa-jet or flow=jet carb, they both tune more accurately than the vacujet which most of the 2hp came with.
For more torque, install the 3hp crank and rod as mentioned above, this will increase displacement and compression, but it is no longer a 2hp engine.
BS 2hp with the stock crank has pretty low compression, be careful about removing too much metal under the head (eyebrows and such). Just rounding the edge of the cylinder bore in the area not covered by the head gasket (stay above the top ring) about 1/16-1/8 radius will provide improved flow in and out of the cylinder without affecting compression.
Clean up the exhaust port, removing all sharp edges and make sure the inlet end of the exhaust is flared internally to reduce turbulence going out or the port.
Do the same to the intake port but use some liquid steel or similar to fill the large square corners in the bottom side of the port, you goal is to try to maintain the same size opening all the way through the port and have smooth (not polished) surfaces all the way from the carb to the valve.
Polish the heads of your valves (they are part of the combustion chamber)
For stock looks but improved power, install a pulsa-jet or flow=jet carb, they both tune more accurately than the vacujet which most of the 2hp came with.
For more torque, install the 3hp crank and rod as mentioned above, this will increase displacement and compression, but it is no longer a 2hp engine.