hkeiner
Lieutenant Junior Grade
- Joined
- Oct 17, 2006
- Messages
- 1,055
I am considering buying the Sheffield Research/GTC (SR TA100) SmarTach Plus Digital Tachometer/Secondary Ignition Voltage Tester. However, I am not 100% clear on how this meter works and I have not been able to find a user manual on-line to find out before I buy it.
Link: http://www.amazon.com/Sheffield-Research-PlusDigital-Tachometer-Secondary/dp/B0002T5TRS
This is how I think the TA100 meter works:
For the tachometer function, The meter's extending antenae picks up the ingnition signals from the air, converts them to RPM based upon the number of cylinders firing per revolution, and displays the result on the meter. The clip at the end of the antennae is NOT attached to a spark plug wire. Since the motor's RPM is not measured from an individual spark plug wire, comparing rpm readings at each wire (in order to detect an inconsistent spark on a single cylinder) is NOT possible. I have read on the forum elsewhere that comparing tach readings taken on individual spark plug wires can highlight an intermittant spark problem. i.e., if the rpm reads much lower on one cylinder than the rest when engine is idleing. However, I am not 100% sure that this meter can measure the rpms using individual spark plug wires.
For the Secondary Ignition Tester, the clip on the end of the antennae is clippped to a spark plug wire to check the voltage in that wire. The voltage level and comparison between wires would hightlight any weak voltage going to an individual cylinder's spark plug.
I would like to buy the TA100 so that I can, among other uses, test the ignition spark on my 1996 Mercury 150 HP outboard to see if the rough idle I have is due to a weak/intermitant spark on any cylinder. I want to confirm that the spark is OK before I mess with the carbs (remove/clean/reinstall/adjust) or the timing. I understand that a seperate DVA meter can be used to check primary ignition voltage components, but not the secondary voltage. I figure that confirming that the secondary voltage is OK using a TA100 would be a more conclusive test.
Have I got this right? Any input would be appreciated.
Thanks
Link: http://www.amazon.com/Sheffield-Research-PlusDigital-Tachometer-Secondary/dp/B0002T5TRS
This is how I think the TA100 meter works:
For the tachometer function, The meter's extending antenae picks up the ingnition signals from the air, converts them to RPM based upon the number of cylinders firing per revolution, and displays the result on the meter. The clip at the end of the antennae is NOT attached to a spark plug wire. Since the motor's RPM is not measured from an individual spark plug wire, comparing rpm readings at each wire (in order to detect an inconsistent spark on a single cylinder) is NOT possible. I have read on the forum elsewhere that comparing tach readings taken on individual spark plug wires can highlight an intermittant spark problem. i.e., if the rpm reads much lower on one cylinder than the rest when engine is idleing. However, I am not 100% sure that this meter can measure the rpms using individual spark plug wires.
For the Secondary Ignition Tester, the clip on the end of the antennae is clippped to a spark plug wire to check the voltage in that wire. The voltage level and comparison between wires would hightlight any weak voltage going to an individual cylinder's spark plug.
I would like to buy the TA100 so that I can, among other uses, test the ignition spark on my 1996 Mercury 150 HP outboard to see if the rough idle I have is due to a weak/intermitant spark on any cylinder. I want to confirm that the spark is OK before I mess with the carbs (remove/clean/reinstall/adjust) or the timing. I understand that a seperate DVA meter can be used to check primary ignition voltage components, but not the secondary voltage. I figure that confirming that the secondary voltage is OK using a TA100 would be a more conclusive test.
Have I got this right? Any input would be appreciated.
Thanks