2
210061741
Guest
Andrew
You wouldn't be wasting your time you will see some gains.
However adding a SBP Expansion Chamber will get that engine running sweeeet.
Here is what i do to my cylinders and it has worked very well for me.
Tools tools tools
A degree wheel and indicator help to find your current port timing.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10841.jpg
YOU NEED A SET OF CALIPERS OR VERNIERS TO MEASURE.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10955.jpg
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10956.jpg
#1 check the clearence between the piston and the head.
A) use a piece of plumbers solder stick it through the spark plug hole and roll the bike to squish the solder between the piston and the head.
It needs to completly turn 1 stroke.
Measure the thinnest part of the solder where it is crushed. That is the squish clearence.
I set mine between .020 and .025 don't get any closer.
You can change the gasket, sand the head, or sand the top of the jug to do that.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10848.jpg
#2 I cut the exhaust port roof to measure 1.060 inches from the top of the cylinder.
If you take a piston and turn it updise down you can slide it in the cylinder and measure down to the flat edge of the piston. Then hold it in place and use a permanent marker to set a guideline.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10851.jpg
Rough it out with drill burrs or a dremel and use files when you get close to the line.
Polish it to a mirror finish
http://i887.photobucket.com/albums/ac72/RidingRich/IMG_0515.jpg
#3 The intake port i cut to (got to look it up) roughly about 3 mm off the bottom.
The trick is to cut the ports more of an angle so that you raise and lower the most at the cylinder bore.
Otherwise you get the gasket sealing surfaces cut too thin.
Make sure to chamfer the edges of the port in the cylinderbore.
Don't touch the transfers or you ruin the thing.
When i am all done i cast moulds of the ports using canning wax.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10857.jpg
That way i get a very very accurate Area Measurement and know exactlly what i have.
You can widen the exhaust port too. Just watch the threaded holes and don't go to wide or you risk breaking the rings.
The intake i would only clean up the sides and not really remove alot of material.
I will start a new more deatiled theread on porting.
YOU WILL HAVE TO TUNE YOUR CARB INCLUDING CHANGING THE JET POSSIBLY.
You wouldn't be wasting your time you will see some gains.
However adding a SBP Expansion Chamber will get that engine running sweeeet.
Here is what i do to my cylinders and it has worked very well for me.
Tools tools tools
A degree wheel and indicator help to find your current port timing.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10841.jpg
YOU NEED A SET OF CALIPERS OR VERNIERS TO MEASURE.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10955.jpg
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10956.jpg
#1 check the clearence between the piston and the head.
A) use a piece of plumbers solder stick it through the spark plug hole and roll the bike to squish the solder between the piston and the head.
It needs to completly turn 1 stroke.
Measure the thinnest part of the solder where it is crushed. That is the squish clearence.
I set mine between .020 and .025 don't get any closer.
You can change the gasket, sand the head, or sand the top of the jug to do that.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10848.jpg
#2 I cut the exhaust port roof to measure 1.060 inches from the top of the cylinder.
If you take a piston and turn it updise down you can slide it in the cylinder and measure down to the flat edge of the piston. Then hold it in place and use a permanent marker to set a guideline.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10851.jpg
Rough it out with drill burrs or a dremel and use files when you get close to the line.
Polish it to a mirror finish
http://i887.photobucket.com/albums/ac72/RidingRich/IMG_0515.jpg
#3 The intake port i cut to (got to look it up) roughly about 3 mm off the bottom.
The trick is to cut the ports more of an angle so that you raise and lower the most at the cylinder bore.
Otherwise you get the gasket sealing surfaces cut too thin.
Make sure to chamfer the edges of the port in the cylinderbore.
Don't touch the transfers or you ruin the thing.
When i am all done i cast moulds of the ports using canning wax.
http://i887.photobucket.com/albums/ac72/RidingRich/SDC10857.jpg
That way i get a very very accurate Area Measurement and know exactlly what i have.
You can widen the exhaust port too. Just watch the threaded holes and don't go to wide or you risk breaking the rings.
The intake i would only clean up the sides and not really remove alot of material.
I will start a new more deatiled theread on porting.
YOU WILL HAVE TO TUNE YOUR CARB INCLUDING CHANGING THE JET POSSIBLY.
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