Wait a minute, you have had the tank off?????

If yes, you need to check all your connections to the tank are proper. The most common error is people connecting the little tube to the lower nipple on the petcock without looking for the proper connection farther back. After you take the tank off a couple - three times, then you get it. It's just a vac line but it's got to be in the right hole.

she said.

 

see above post...

 

what is the main fuse? There is a fuse box with 6 or so fuses... I've got the shop manual, and I can't even find any references to fuses...grrrrr.

 

Took the tank off twice - third time since I bought it, I believe I got the tubes in the right place - yes, there's that downward pointing connection with no hose, weird.

 

Make sure you don't have the little hose that goes into the bottom of the tank reversed with the one that goes to the back of the petcock. They are approx the same length and diameter and could be inter changed.

 

Did you shut off the petcock and not turn it back on when you reinstalled the tank?

 

On the left hand side of the bike, underneath the rear fairing. It is the circuit that controls the starter motor, so it is a separate fuse. I cannot recall whether it does anything else, but I would think not. If the bike is turning over then it should be ok.

If you have spark then then I would be back to fuel for a while. You need to make sure that the carbs are receiving the fuel from the tank, and there are two things that will stop that. If you have turned the petcock off then that is one possibilty. The other is that the vacuum hose mentioned above may be in the right place, but is it providing vacuum to the petcock? Check that it is. The other option is that the petcock diapragm is broken. Both of these will cut your fuel off.

 

If it was the main fuse the bike wouldn't even crank.

I'm on board with the thought that the vacuum line wasn't hooked up to the tank valve.

 

I doubt that there is a hose connection problem, since it was running good for the longest time, didn't mess with anything, then suddenly crapped out. It appears to me that fuel is flowing from the petcock, cuz the tubes have gas in them.

 

They won't be empty even if fuel is not flowing, it will have to suck air to be filled with air, so don't assume the carbs get fuel because the hoses are filled with gas, they will be anyway.
Take a 2 $ syringe and pull vacuum on the petcock, if gas pour out, it works, and verify that the vacuum hose running to the rear cylinder is not cracked or pinched.
To check spark pull the plugs hook the wire and rest it on the frame/engine.
Compression, well you just can listen to it cranking, if it stumbles every compression (normal), otherwise it's abnormally smooth.

 

had it taken to the local stealership. Turns out it was a marginal battery amperage. Would have never thought of that. They said they charged the battery and runs great.

 

That's odd, since cranking is the first thing that would be affected by a low battery. Was it cranking at normal speed, or slow? It may ultimately be a R/R problem.

Can't argue with success though, batteries don't last forever....go out and ride it.

 

Ya, it seemed to crank fine for me, and it was producing spark. I have experienced many a car battery go bad, and the first sign is it doesn't crank. I gotta quiz them more tomorrow when I pick it up.

What is an R/R?

 

Rectifier/Regulator is a known problem on earlier VTRs. It would overheat and fail. Do a search to check it out. Easy replacement.

Rectifier is made up of 6 diodes that change the alternator output from a/c to d/c.

Regulator controls charging voltage and amps.