i have replaced my factory speedo with a Medallion Speedometer. worked good for the summer.. now my tach is everywhere from 400 to 9000... back and forth, the entire time i am riding it is never right even at idle. speedo is fine and not effected.. this is a problem in either mode needle or digital. is it the tach or a sensor? any help would be great..
Medallion Speedometer tach problem
- Thread starter gooby63
- Start date
Five Five
Well-Known Member
That's right Mikie. Tach sends signal from ignition / coil
BigDogBro1
Made in the USA
It's an intermittent wire connection, probably in the Speedo head. Or a tach bd going bad. If you haven't checked the EHC harness connections, you need to clean and dielectric grease them. Do a search on dielectric grease. Use isopropyl alcohol and cotton swabs to clean. Be gentle on the connector pins, they can bend or break.
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bearman
Active Member
Are you using suppression plug wires? If you are not you need to be.
francoblay1
The Spaniard
As bearman said.... have your spark wires been changed? If so, that could be the problem.... they must be suppressed.
http://www.magnecor.com/magnecor1/main.htm
For Big Dog the Part # is 2902
http://www.amazon.com/Magnecor-R-10...qid=1441872238&sr=8-11&keywords=magnecor+10mm
http://www.magnecor.com/magnecor1/main.htm
For Big Dog the Part # is 2902
http://www.amazon.com/Magnecor-R-10...qid=1441872238&sr=8-11&keywords=magnecor+10mm
cdogg556
Guru
How do you know if your wires are surpressed or not Franco? And how would that effect your tach?
I noticed when my tach comes on that the lights look like they are pulsating also!
francoblay1
The Spaniard
Have a read at the Magnecor webpage or do a search in Google about this subject. Big Dogs are VERY sensitive to this matter.... Sparkplug wires on our Dogs MUST be suppressed.How do you know if your wires are surpressed or not Franco? And how would that effect your tach?
Here a couple links.
http://www.magnecor.com/magnecor1/truth.htm
http://www.auroraelectronics.com/Understanding Spark Plug Wires.htm
Srodden
Well-Known Member
Clean sensor on tranny good to go
bearman
Active Member
Non suppressed ignition wires emit radio waves. If you've ever heard the alternator whine in a car stereo system, it's kind of the same thing, but worse. If you have ever been at a red light and had a hot rod car with non suppressed ignition wires pull up next to you, you will hear it affect your radio.
Now, that being said, just about every electronic thing you can buy for a motorcycle used to have a requirement to mount the electronic brain 1 meter (3 feet) minimum from the coil and ignition wires. This is because of the radio wave interference that is caused by the coil and ignition wires.
Now, I wish someone could tell me where you can mount anything on a Big Dog that is more than 3 feet from the coil. Maybe the leading edge of the front fender.
But now most things no longer have this warning, I saw one for 30cm (12 inches) but that was about it (but it did require radio suppressed wires). I guess most things are shielded now. Thunderheart used to have this warning for their ignition module, now they have a bracket to mount it directly to the coil.
bearman
Active Member
The emmision of radio waves probably won't affect the ignition module but could affect the speedo/tach and/or EHC.
But a bad wire can cause misfires and cut-outs, especially if it is letting the spark jump to ground, check this by looking at the wires while the engine is running in the dark. Sometimes it's a bad plug boot, or maybe just that water got in the wire-to-plug boot joint. Spraying this with WD40 can temporarily fix this.
francoblay1
The Spaniard
Told ya but you don´t listen!!!Ok, that totally makes sense now,so what if you have a plug wire that maybe is bad and is emitting radio waves do you think it could cause the ignition to screw up and cause the bike to actually cut out and die intermittently?
