Early Yamaha Viragos (1982 and 1983) I have been told have a notorious
starter problem that slowly develops. I'm no mechanic, but I've been told
the starter gears end up having trouble engaging the flywheel, or something
like that. I've also been told a new starter will not fix the problem, and
the bike is SOL once it reaches this stage.
Anybody familiar with this problem, and whether there is a workaround?
Mike Miller·Saturday, May 30, 2020·
Final starter fix- MIKE MILLER MOD
(See original post below- HISTORY)
Okay, let me put it this way.
The 'starter problem' is an electrical problem FIRST and a mechanical problem SECOND.
The TCI needs stable voltage to work.
The many actions inherent in cranking a big v-twin causes a wildly varying load on a battery, especially a battery that is not strong and fresh. This load variation translates to a VOLTAGE FLUCTUATION...which can switch off the TCI while cranking.
Result: NO SPARK!
The stabilizer- a simple $15 piece- makes sure the TCI gets clean voltage.
So, with the stabilizer, if the battery is strong enough to get the piston over Top Dead Center on compression stroke, you will get spark. BOOM!
(Did you ever let off the start button and suddenly fire up strong? Like a kick-start? It can happen that you let off just as the piston if flying upward on the compression stroke fast enough to get over the top, and the voltage is there right as the TCI needs it, so the engine starts! That is what caused me to use an OSCILLOSCOPE to chart the voltage while cranking. The voltage swings wildly! Then, I separated the TCI from the rest of the harness, used a SEPARATE battery to feed it, and the engine started cleanly EVERY TIME, verifying the cause. The stabilizer is like a small separate battery for the TCI.)
Yes, a big new battery will get a good strong start. So will jump-starting from a diesel truck!
Yes, renewing the gears will likely keep you cranking and MAYBE start...until the gears again disengage, as explained in my post -"Final Fix for Starters".
Yes, removing the disengagement spring will give you a little more engagement. It can also allow the gear to hang up on the flywheel and wear out other parts of the starter drive. (It sounds like something still buzzing in the case.)
So, I'll say this- GET the stabilizer. Put it in.
If you have EVER had a start problem on the old-style starter designs, just get the stabilizer.
ALL OTHER FIXES are fixes of the EFFECTS of bad, dirty, fluctuating voltage. Strong batteries and sharp gears will always help.
Michael J. Miller
Original owner of a 1981 Virago 750
138,000 miles and still using the original factory designed starter system.
HISTORY- MY ORIGINAL POST
The final "fix" to starters, carbs, and weak spark.
Many years back, I posted to DR. PISTON about getting a hotter spark by using the ACCEL HARLEY SINGLE-FIRE COIL. Many of you followed that advice based on my finding that the spark-during-crank was sometimes too weak to fire the rich mix.
It IS a good upgrade, but I wondered WHY the spark was weak on start. So, I hooked up a dual-trace oscilloscope to get a real-time look at the action. What I found was that the juice needed to crank that big piston to top-dead-center for the fire could drop the voltage momentarily to as low as EIGHT VOLTS!
The TCI will not work with less than TEN VOLTS, so, as the piston was getting ready to fire, THE TCI SHUT OFF!
Further, I had noticed that sometimes, as I let off the start button, the bike would then fire. With the info from the trace on the scope, it made perfect sense. Once the voltage came back up, it fired just like kick-starting
Next, I took a small separate battery and used it to juice only the TCI. This kept the voltage to the TCI stable at 12V.
BINGO! It started right up!
So, NOW, OFFICIALLY, I offer this final fix to the start question.
Get this voltage stabilizer, hook it in between the wiring harness and the TCI on the R/W wire. And I will bet you that the bike starts just the way you always hoped.
All the bikers I rode with would wait for me to get my cantankerous Viragosaurus '81 to start before they would touch their keys.
Then, after this change, I was cranked and gone, and they had to CATCH UP!
PS- The starter disengaging is mentioned in another post, but here is what happens-
The starter can't keep up with the piston after it hits TDC in compression. The compression pushes the piston downward too fast to keep the gears engaged, so the starter gear partially disengages with each revolution until it jumps out and spins. IF THE PISTON FIRES ON THE FIRST OR SECOND TRY, the starter stays engaged long enough.
SO, when I start my bike, I NEVER hold the start button longer than 2 revolutions. Then let off and do it again. In 130,000 miles, I have made NO CHANGES to my starter gears except to replace the starter with a 4-brush solid magnet starter.
DC Voltage Stabilizer 8-40V to 12V 6A 72W Car Power Supply Regulator Waterproof | eBay
DC Voltage Stabilizer 8-40V to 12V 6A 72W Car Power Supply Regulator Waterproof