can i connect a 30-4900 Wideband Failsafe Gauge to a magneto electric tach converter? | AEM
3 posts / 0 new
Last post
kevin
Offline
Last seen: 4 years 10 months ago
Joined: 04/18/2015 - 22:47
can i connect a 30-4900 Wideband Failsafe Gauge to a magneto electric tach converter?

hey folks

i'm building an LSR race machine from a 1964 triumph bonneville motorcycle. the machine has no alternator and runs a total loss 12-volt negative ground lithium battery. the ignition is an ARD single-points dual-fire magneto (fairbanks morse, 1:1 drive from the camshaft) with no connection to the 12-volt wiring harness. i'd like to know whether the AEM failsafe gauge system can be attached to the bike to give me an RPM trace along with the A/F readings.

there are no external connections on the magneto except the single ground-to-kill terminal and the plug secondary wires. but morris magneto makes a converter which allows a fairbanks morse magneto to trigger electronic (not digital) tachometers:

http://shop.morrismagneto.com/products/elec-tach-module

their converter has three wires: ground, tach trigger, and magneto ground-to-kill terminal. i know that your failsafe unit needs a clean square wave signal, but i know little about electronics.

questions:

1) does the fact that the morris converter will *not* trigger a digital tach indicate that it also will not  trigger your failsafe uego gauge unit correctly?

2) i'm running an unfaired stripped motorcycle to 130 mph, and long wiring harnesses are a problem. can i cut and splice the power and sensor leads to shorten them if i keep the correct terminals?

many thanks

 

 

AEM_NS
Offline
Last seen: 1 hour 33 min ago
Joined: 06/06/2014 - 09:31
That little mag tach adapter

That little mag tach adapter thing needs to have its signal output checked on an oscilloscope.  If it looks like a coil primary signal then it should not be used as it could damage the gauge.  If it's a clean square wave then it should work.  Perhaps the manufacturer will have this information for you.

kevin
Offline
Last seen: 4 years 10 months ago
Joined: 04/18/2015 - 22:47
thank you for the quick

thank you for the quick response. i can certainly check the converter signal on an oscilloscope. i'm afraid the ignition itself is some 40 years old, using a magneto that goes back probably 30 years more, so i'm on my own in general.

but i'll check with morris magneto to see what they say.

thanks again