dropped cylinders 2 & 3...????

[DiverRay]

It's not really that hard. Pull the allen holding the timing plate on, pull the plate out, put a nut or two on the allen bolt and put it back in snug. You can now pull the 4 spark plugs and turn the crank over with the allen to check the clearance.
The wires from the pick-up coils can be checked by just pulling on them, and seeing if the insulation has an hourglass look. The wires normally break near the crimps that hold them close to the plate. Yamaha over-crimped them, and that is why they break. I tried to tell them that back in '78 when I had a wire break on my first XS, and was working in a shop as a mechanic.
The slot in the back of the timing plate is off center, so it will only go on one way. If you move the backing plate, use a pencil to get TDC on #1, and line up the pointer. This will get you close and the bike will run ok to well, depending on how close you got.

[BA80]

The timing won't move unless you take that large aluminum piece with the 2 bolts with slotted holes. Even if you do have to remove that for some reason just mark it and put it right back where it was.

[MadHatter4119]

Easy for you guy to say...Its all Greek to me...I'm not at the point yet...I want to see if another TCI corrects the problem and puts some life back into
2 & 3...Like they say...If it ain't broke...Don't fix it !!! Lol

[MadHatter4119]

Well...It appear I lost cylinders 2 & 3 due to a bad TCI...Borrow one today and now all cylinders are running...I need to put a cover of some kind over the
pickup wire from the pickup cover to where the wires goes up under the engine
...its only 6" or so...Checking for broken pickup coil wires I cut off the protective cover...now it need to be recovered because they run near the exhaust pipe...Hopefully , I can find something that will slip over the wires and
not the kind where you need to feed the wires through...What have you used? Also...Even though its firing in all cylinders...I don't think the spark looks as strong as it should be...????
...I clean all the connections in the ignition system and cleaned the grounds...Is the black wire coming from the TCI the ground...I'm thinking about running it to frame...I took apart an 1982 Yamaha Virago 920 harness
one time...and the splicing in it was enough to make you wonder what the crap was they thinking...On the Virago...If it had a ground wire...I ran it to the frame...everything improved...The lights and blinkers were brighter...the charging system was better...the spark at the plugs looked bluer and bright...it just ran better after the ground mod...Later

[CaptonZap]

Hey MH, check your private messages.
Thanks, CZ

[Bonz]

CZ, you able to do the TCI repair?

[MadHatter4119]

He just wanted my old ones...I'm waiting on a reply to a PM I sent him...Has he repaired many TCI'S...I was trying to find out the cost to have one repaired
...There is a guy on the ViragoTech.Com forum that repairs Virago's TCI and
thought about contacting him to see if he wanted to try his skills on one of ours...Later

[MadHatter4119]

Well...Like they say...If it isn't one thing...Its another...It never ends with
this bike...I got fire back in all 4 cylinders when I put another TCI in it...Today
I let it warm up to running temp...I would guess in about 6 to 8 minutes it
started popping real bad and a cloud of black smoke came out the exhaust...
Once it popped and shot a 4" flame out the exhaust...Now it won't idle long
before dying...it starts back up...when I rev it a little bit...it's missing bad...If
I rev it higher it will pop and black smoke will come out the right muffler...I
can't explain it any better...started to rain so I just packed it in for today...

Thanks

[DiverRay]

Today
I let it warm up to running temp...I would guess in about 6 to 8 minutes it
started popping real bad and a cloud of black smoke came out the exhaust...

OK, did you have a fan running air over the engine? after three minutes you DO need to have airflow to keep from overheating the engine.
IF it's just right side, my guess is #3 or #4 carb has a problem. Make sure the vent isn't plugged.

[MadHatter4119]

No fan...it was rather cool today...upper 40's...Now that I think about it...It
may have only been 4 or 5 min at the most...I'm not sure what vent you are
talking about...

[BA80]

The bowl vents.......they look like fuel inlets but are above the actual fuel inlets. Between 1 & 2 and 3 & 4 carbs.

Lemme see if I have a picture.

[BA80]

You can kinda see them here, just above the fuel inlets.....

[BA80]

You can see them good in this pic.........

[motoman]

Well...Like they say...If it isn't one thing...Its another...It never ends with
this bike...I got fire back in all 4 cylinders when I put another TCI in it...Today
I let it warm up to running temp...I would guess in about 6 to 8 minutes it
started popping real bad and a cloud of black smoke came out the exhaust...
Once it popped and shot a 4" flame out the exhaust...Now it won't idle long
before dying...it starts back up...when I rev it a little bit...it's missing bad...If
I rev it higher it will pop and black smoke will come out the right muffler...I
can't explain it any better...started to rain so I just packed it in for today...

Thanks

Definitely sounds like secondary ignition issue.........remember, 'electrical before carburation'.

[BA80]

Why only the right side then Brant? 3 & 4 have nothing in common except fuel delivery.