News:

We would like to thank our supporting members for their generosity.

Main Menu

Fixed my speedo problem, now I have a tach problem...

Started by Manmelvin, February 09, 2016, 02:21:39 AM

Previous topic - Next topic

Manmelvin

So over the past few days I have been pulling my Vision out of its winter slumber (carb clean, new plugs, new fluids, etc.). Besides the normal maintenance I also attempted to fix the annoying speedometer squeal that I experienced for a few months before I put the bike away for the winter. I did this by turning the dash assembly upside down and dripping a bit of low weight lubricating oil through the speedo cable port. After two days of work and one small engine fire, I put it out pretty quick and learned to go easy on the starter fluid, I got my bike up and running. Everything seems to be working fine, with no more squealing speedo however my tachometer is now off at lower RPMs. I would say that anything lower than 2500 RPM the tachometer seems to be reading too high. At an idle that sounds like it is about 1000-1500 RPM the tach displays something near 2700 RPM instead. Also when the bike is off the tach needle doesn't go all the way back to zero and sits at around 300 RPM. Is this an electrical issue or did I manage to gum up the gauge assembly itself by putting a bit of oil in there?
Red 82' Vision w/ Upgraded Carbs and 83' Risers

b_racuda

It started with some problems at starting my vision. After a while I started to have tachometer problems and after that also problems with the TCI. The tacho was having the same symptoms that you descriped before the bike started to have problems with the ignition. So unfortunately tachometer problems are sometimes symptoms from broken TCI. Please read http://www.jetav8r.com/Vision/IgnitionFAQ.html#a2p2

I ordered new TCI from Ignitech http://www.ignitech.cz/en/vyrobky/tci/tci.htm

QBS

Permanent fix for speedo squeal is to force grease into the cable receptor area.  The receptor is closed ended and will allow no grease to enter the speedo interior.  BUT, the act of trying to force grease into the interior will force grease into the space between the cable receptor and the housing it lives/turns in.  That is where the squeal ordinates from when the factory lube disappears after 20+ years.

The tach gets its' signal from one of the spark coil low tention wires, grey I think.  Clean all the low tention wire connections at the spark coils and also the ground wire that uses the spark coil mounting to the frame as a source of grounding.  I've had two TCI boxes fail.  Both did so without warning. In TCI fail mode the bike would start and idle normally on two cylinders.  When the tach went beyond 2000 rpm one cylinder would stop firing.  The rpm could be raised higher but only on one cylinder.  When the tach dropped back to 2000 rpm or less the bike ran/idled as normal.

b_racuda

Tach gets its signal from the grey wire. My TCI fail started with no ignition fails but strange behauvior of tacho. When bike turned off the tacho showed some rpms, also the needle was acting strange when riding. After few rides after that the ignition started to fail. The bike idled normaly but when the revs were above 2000 the other cylinder did not fire and the power was gone. This lasted about 20sec and then it was back to normal.

I think I had problems with the TCI also before that but did not realize it. The bike was not starting proberly even I had all connections cleaned, groundings checked, spark plugs changed to iridium, spark plug wires and caps changed and carbs cleaned.

But it is worth trying to check ad clean all connections. It will do no harm and can be easy and cheap fix :)

Manmelvin

I will go through all of the wiring and report back. I have an extra TCI and two coils in my parts bin but I am unsure if they are in working order.
Red 82' Vision w/ Upgraded Carbs and 83' Risers