Two neat homemade tools to share...
11-15-2004, 01:41 PM
#1
Two neat homemade tools to share...
Hi again guys,
Here's a couple of tools I've made that I think you guys will appreciate...
One is a screwdriver with a shield on it for adjusting carburetors. I try to mount my carbs with the adjustment screws accessible with the engine running whenever possible. It makes it MUCH easier to fine tune the motor without starting and stopping it a hundred times. I think this is just as safe as the glow motors we have all adjusted with the engine running; you just have to be careful as always. It isn't all that safe starting and stopping the motor a bunch of times to tune it either! Anyway, the shield is made out of the insulation off a large (yellow) size electrical crimp connector, glued to a small screwdriver. It fits perfectly on the carb screws, and keeps the screwdriver from jumping off the screw due to vibration. It is helpful to mark the sides of the shield to indicate where the blade of the screwdriver is inside for reference.
Next is a timing tool. The only accurate way to find top dead center is with the "Positive stop" method. The piston has a "dwell time" at top dead center, where the piston does not move for a significant number of crankshaft degrees in rotation. The only way to find true top dead center is to use something to stop the piston from reaching the top. You then set your degree wheel to show an equal amount of degrees on either side of this stop. Then, when you remove your stop, the degree wheel will indicate actual top dead center when it is on zero. Now you can use a screwdriver or something stuck into the spark plug hole to do this, and hope it won't move and throw off your readings, or make this neat little tool out of an old spark plug. The stop, as you can see, is a piece of tubing glued into the center shell of the spark plug. The tube is the stop, and it also allows air to escape as you turn the engine over. Neat huh? It works great.
So to reiterate, you screw this tool into the spark plug hole. You then gently turn the engine over until it stops. Note the degrees indicated on the wheel, then gently turn it in the other direction until it stops again, and note this degree wheel indication. Move the degree wheel until it indicates exactly the same in both directions. Now you have top dead center properly set on the wheel. Remove the stop tool, and go ahead and set your timing.
Have fun,
AV8TOR
Here's a couple of tools I've made that I think you guys will appreciate...
One is a screwdriver with a shield on it for adjusting carburetors. I try to mount my carbs with the adjustment screws accessible with the engine running whenever possible. It makes it MUCH easier to fine tune the motor without starting and stopping it a hundred times. I think this is just as safe as the glow motors we have all adjusted with the engine running; you just have to be careful as always. It isn't all that safe starting and stopping the motor a bunch of times to tune it either! Anyway, the shield is made out of the insulation off a large (yellow) size electrical crimp connector, glued to a small screwdriver. It fits perfectly on the carb screws, and keeps the screwdriver from jumping off the screw due to vibration. It is helpful to mark the sides of the shield to indicate where the blade of the screwdriver is inside for reference.
Next is a timing tool. The only accurate way to find top dead center is with the "Positive stop" method. The piston has a "dwell time" at top dead center, where the piston does not move for a significant number of crankshaft degrees in rotation. The only way to find true top dead center is to use something to stop the piston from reaching the top. You then set your degree wheel to show an equal amount of degrees on either side of this stop. Then, when you remove your stop, the degree wheel will indicate actual top dead center when it is on zero. Now you can use a screwdriver or something stuck into the spark plug hole to do this, and hope it won't move and throw off your readings, or make this neat little tool out of an old spark plug. The stop, as you can see, is a piece of tubing glued into the center shell of the spark plug. The tube is the stop, and it also allows air to escape as you turn the engine over. Neat huh? It works great.
So to reiterate, you screw this tool into the spark plug hole. You then gently turn the engine over until it stops. Note the degrees indicated on the wheel, then gently turn it in the other direction until it stops again, and note this degree wheel indication. Move the degree wheel until it indicates exactly the same in both directions. Now you have top dead center properly set on the wheel. Remove the stop tool, and go ahead and set your timing.
Have fun,
AV8TOR
