Losing Electricity?

[cvincer]

From the website I got this:-

top9.2 [TCI MODULE VOLTAGE DROPOUT TEST]
Check that you don't have a bad wire or connection to/from TCI. You are looking for voltage "dropouts". You should not see more that 1/4 volts in these checks. More means you have a wire or connector that is literally diverting power or making a poor ground.
>> Set voltmeter to low scale 1-3 volts.
>> Put RED test lead on +12 battery post. Put black test lead on these TCI pins with wires connected :
RED/WHITE striped , ORANGE , GRAY wires


                         ........ when I put the black test lead onto those wires   (i.e the 6 prong connector is

plugged into the TCI, & the test lead goes into the back of the connector) ....... I get 12.6 volts ....&

the bike runs.

                             Is the web info correct?   Have I read it correctly?   Have I hooked up correctly?

And the $64,000 question  ...............  if I am 'losing electricity" , can anybody explain how I go about

finding the leak, please?   

Note:-  the battery to ground connection is good, & also the LH coil to ground connection.

[Lucky]

what website are you looking at?

[cvincer]

  This one:-
 

  TCI & CDI Electronic Ignition / Stators & Charging Systems
This guide was started for the "YAMAHA VISION" motorcycle group (http://ridersofvision.net/). However, much of this info applies to any ignition / charging / electrical system. Specifically, how this stuff works, how to trace problems, and ultimately how the driveway mechanic might fix an electric, ignition -or- charging problem . If you have comments or corrections... PLEASE email. I will update this when I can. ©1999   Dave "Leather" Draper   Jetav8r@JetAv8r.com   . My Vision Info Site Here.
   


"Yamaha Vision" Motorcycle
Electronics / Ignition FAQ
Version 4.0 (July 2005)

Designed for 1024x768 screens
   

[Lucky]

Ok, your starting in the complicated middle.  lets start with the basics:

what's wrong with your bike, what is it doing (or not) doing?

not starting?
does it crank?
does it crank fast or slow?
does it ever backfire when it cranks?
does it ever go 'KER-CHUNK!' from the left case when it cranks?

you have to start at the basics & at the beginning.  sometimes you can end up going thru a lot to solve a simple but hard to see problem (see "Petcock affects startability")

--Lucky

[cvincer]

It's only problem is the occasional misfire as I'm heading down the freeway anywhere between

6 - 9000rpm.    I've replaced plugs, leads, coils & the TCI.   Earth connections are good.   Stator & R/R

check out good (as per that website advice).    The rev limiter wire is disconnected.   I don't have  any

sidestand switch  .................. the only thing out of spec was the voltage mentioned in the 1st post

[Hartless]

when is the last time that you did a full tune up , including valve clearances and all? i thats what was happening to mine , and then i bent a valve , clearance and timing was off i suspect, and i dont drive at 9000 rpm often ( but i was when it went caput )
and couldnt really tell

[Lucky]

Ok, I think your test readings are correct.
I think what Dave is trying to describe here is a 'voltage drop test' where you have a wire that runs fom point A to point G (lets say) & makes several connections along the way. you want to measure between a & b, then a & c, a & d, a & e, etc, etc.

idealy you'd have the same voltage at every test, but realisticly your going to have some drop at most every connection. if you drop below 9.5 on input voltage, the TCI won't fire. (A Vision with a weak battery will never start..)
I think that's what Ron was trying to convey.

So, lets move on to your 'occasional misfire' at 6-9K.

when you say misfire do you mean it will suddenly run badly for a period of time, as if only sparking randomly?  only on decel?   will it "Hesitate" when you twist the throttle hard, then it'll 'catch' quickly & haul, or something else?

[cvincer]

Mr Hartless .....  the strobe shows the ignition timing is spot on,  my plugs are a nice light brown color so
                       the mixture is ok.  I have balanced the carbs & apart from my problem it runs nicely. The
                       valve shims have never been touched, & as I've never dealt with anything other than
                       pushrod operated valves  +  don't have that special tool required, don't want to go there


Mr Lucky  ......   Yep, I sometimes get the  hesitation/Vision stumble when I snap open the throttle.
                       This misfire happens as I'm going along at a steady 'freeway' speed/rpm .... I can
                       feel the occasional miss; the rev counter needle doesn't waver (& at high revs the
                       needle probably hasn't got time to register the occasional miss), so no clue as to a
                       front or rear cylinder problem.
                         

[Lucky]

ok, i'm getting an idea...

what year is the bike? it matters.

[cvincer]

   An Australian 16R    1982

[Lucky]

While no one wants an occasional miss, i thought what you were experiencing was a lot worse, that's ok though.
If you have an intermitant problem, you might have a hard time finding it until it gets worse...

we'll start with a couple of scenarios, a couple of possibilities & places too look.

First off, you said the tach doesn't show any miss.  it's importaint to remember that tach readings only come off the coil with the grey wire, & i believe that may vary by year, but i can't remember where i head it, & now i can't find that info.

Anyway, if your tach's not showing the 'miss' then it's a safe bet to assume it's the other cylinder that is missing occasionally. locate the coil with the grey wire on yours & scrutinize the OTHER cyl/system as you test.

in most vehicles a miss is almost allways electrical.  on the Vision, don't rule out carbs.
-----------------------
You have replaced plugs, wires, coils & TCI.
Did you replace the resistor caps on the wires? are you using resistor plugs? are the replacement coils new or used?
-first thing, do the resistance checks in your Haynes or factory manuals & see what you get. you might be at or near the max. a humid day or loose connection might be putting you over sometimes...

-Check the resistance on the pickups at the plug on the TCI. wiggle the wires, you could have one with insulaton worn thru where they enter the case, or elsewhere.  also, these wires seem to weaken at the TCI plug & you might have to do some repair work there if they are frayed.

-You might want to do a compression test and, if you can, a leak down test & see how those readings compaire.  it might be time for a valve adjustment.

-Give the 'bad' cyl 1/16 - 1/8 turn out on the pilot screw. just to see. Double check your synq.  run half a bottle of fuel injecter cleaner thru the tank for good measure.

i'd start with these. try & take a logical approch.

--Lucky