multi-meters

[ANTI-QUAD]

my manual for my 350 x recomends two specific multi meters for testing my cdi box. can any one tell me what makes these meters differant from other digital meters

[TG]

Digital meters are superior to ordinary multimeters in most respects. Multimeters are recommeded mostly because thats all many mechanics had availiable (different story nowadays). If you can post some details as to what tests they want done on the CDI box, I can try to interpret it. Theres not a great deal you can do without an oscilliscope, "cold" readings arent much use.

PS whats the problem youre trying to solve?

[ANTI-QUAD]

the test procedure is to measure resistance between the termanals to determine weather the cdi box is good or bad.I have a buddy that does electronics work(computerized temp controle and so on)he has modern test equip..I just didn't know if a standard digital multi meter would do the trick such as a Fluke which is a common automotive dig. m.m. the note in my manual reads as follows:the cdi unit is fully transistorized,for accurate testing, it is necessary to use a specified elec. tester. use of an improper tester may give a false reading. It then says to use a Sanwa elec. tester or a kowa dig. multi tester.I did find a sanwa on line,and one of their meters is specificly for motor cycles.Any thoughts on the subject would be great ..... thanks

[ATCnut]

Im an electrical engineer, we have had the same issue with other electrinics tests.

The reason they specify a particular model of meter is that different meters apply different voltages when measureing resistance. Someone mesured a good CDI with the specified meter and wrote down the numbers. Another reason is to use a meter than does not apply excessive voltage

Since a CDI is a active circuit, the resistance changes with voltage.

My experence with trike electrinics is that the only good way to troubleshoot is to have another running trike and to swap things back and forth one at a time.

[ANTI-QUAD]

Hey thanks atc nut,you just confirmed my thoughts.electrical is not my strongest piont when it comes to mechanical work,I know just enough to confuse myself but at least now I know I wasn't over thinking my issue

[TG]

Good explanation on the meters ATCnut. What sort of EE-ing do you do?

A-Q: If you cant get swappable parts, there are other options. Since dealers wont take new electrical parts back, I wouldnt buy new until I was certain what failed.

Your manual calls out a "boundary test" but they are about useless.

First thing id do is remove all the connectors and reconnect them several times to wipe the terminals clean. put a little torque on the wires also. Might reveal a loose connector. A low enough resistance that a common DVM cannot read (like ~1 ohm) can severely cut spark output. A loose or corroded connector can easily go 2 ohms. I had this happen on my ATC250R due to a loose connection from CDI to coil.

if you have access to an air ratchet, you can remove the spark plug and crank the engine via the rear axle (4th gear or so) to get an engine speed of on the order of 500- 1000 R/M then check the output of your pulse coil and stator. Your pulse coil might go on the order of 10-20VAC peak and stator ignition winding on the order of 200-300V. Those figures may show up as 0.1 - 1V and 30-60V on a digital AC voltmeter. If the sources are working, youve isolated it to the wiring, CDI, coil, kill switch etc.

Good luck.

[ANTI-QUAD]

great input tg,between you and atc nut,my brain cramp is starting to relax.I think I will print off the info that both of you gave me and add it to my manual thanks again

[ATCnut]

Im an electronics designer that does Military Avionics. I worked on the flight controls and weapons delivery systems for the B-1b bomber, on a couple of sattallite and space programs, and on one of the new fighters. I am currently working on a upgrade to the US AWACS fleet.

[TG]

OK, wont ask any more. Met some 3C engineers at Wright Pat a few years ago, ... neat stuff. Wish I had their labs to play in. :!: