Timing Wheel 2 stroke set up, a beginner's perspective.

Hope you are all doing well? In this video, I’m attempting to record my stock timing numbers for the exhaust port, transfer ports, and intake port, but first, we have some work ahead of us. Remove the piston ring from your piston. This will help protect your cylinder while you're getting your reading later on. You will need to drill a hole into the Timing Wheel so it will fit the bolt on the magnet side. Not too big. Next you will need to make a Positive Piston Stop. The Positive Piston Stop will be used to time out the piston dwell time, the brief periods of time the piston is at top dead center and bottom dead center.

After you have completed those tasks, you will need to make sure you make a pointer for your readings. The pointer needs to be long so you can move it later. Also it needs to be strong enough that it will not move too much. I place my pointer on the bucking bar sight of the clutch. Remove your magneto prongs as well.

You are really placing the Timing Wheel on the magneto bolt. Place a one washer, your Timing Wheel, another washer and lastly your nut. Do not tighten the nut too tight at this point just snug. Move the Timing With to Top Dead Center (TDC) towards your pointer. Line up the pointer to TDC and snug the nut down just a little. The wheel might move a little. That is okay. Use a wrench to move the nut that is on the Timing Wheel ClockWise. This will move the piston from TDC. Place your Positive Piston Stop on top of your cylinder. Make sure you have the correct amount of base gaskets, spacers, gasket maker (gas resistant), whatever you plan to run already mounted under the cylinder. Take a washer, lock washer and a nut and torque them onto the 2 stud bolts. Torque the nuts to 12.0 to 12.5 foot pounds. Move the Timing Wheel with the wrench till the piston gently taps the Positive Piston Stop. Use the wrench to secure the Timing Wheel nice and snug!!

We are now going to time out the Piston Dwell Time. Take a reading from your wheel sense it is already touching your piston. Remember the number and move the wheel Counterclockwise till the piston touches the Positive Piston Stop. Record the number. If the number is the same then you are done. If the number is not the same, like 31 and 29, move the pointer to the difference of the two numbers. In This case, move the pointer to 30ish. Move the wheel Clockwise till the piston touches the Positive Piston Stop. If the number is 30 then you have found your TDC. If not, repeat the process till you're reading the same numbers in both directions.

Now that you have found TDC you can remove the Positive Piston Stop. Make sure you do not bump your pointer. It can not move now!!!!!!!! After the Positive Piston Stop is off, bolt your cylinder down with washers, lock nuts, and bolts 4 sets and torque then down to 12.0 to 12.5 foot pounds. Move the timing wheel to TDC. Next move the wheel Clockwise. You are moving in this direction because this is the direction your drivetrain will be moving in. Continue to move the wheel until you see the Exhaust Port just barely opens. You can use a flashlight to aid in seeing when the port opens. Record the number, say 72 degrees. Next repeat the same movement until you get to your Transfer Port. Take your reading, say 55 degrees. I found these ports are the hardest to get measurements for. Next, continue to move your wheel until you get you Intake Port opened. Record the number, say 61 degrees.

Next step will be finding the Durations of your ports. Your Port Duration is how long the port is open for during the 2 stroke cycle.


Exhaust opened at 72. 72 times 2 equals 144 degrees of Exhaust Duration.
Transfers opened at 55. 55 times 2 equals 110 degrees of Transfer Duration.
Intake opened at 61. 61 times 2 equals 122 degrees of Intake Duration.

Lastly, will be Transfer Blowdown. Transfer Blowdown is the relationship between the Exhaust port and Transfer Port. Transfer Blowdown is the time between when the Exhaust Port opens until the Transfer Port opens.

Exhaust opening minus Transfer opening equals Transfer Blowdown.
72 minus 55 equals 17 degrees of Transfer Blowdown.