Petcock affects start-ability

[VFan]

Thanks for all the interesting replies. I have been doing a hydrometer check on my cars each winter but didn't know that smaller ones were available for motorcycle batteries.

Some background about my question concerning the conductance battery tester. A couple of years ago I was having problems with my RJ and I suspected the battery to be the source of them. I took the battery to the dealer where I bought it and asked them to check it with the implication that if it was bad I expected them to warranty it. They used this fancy conductance meter to show that it was still good. After further troubleshooting I was convinced that the battery was the problem but the dealer said that the conductance meter is the ultimate test. I circumvented the problem by just buying a new battery somewhere else, but I always wondered if I was missing something or if the conductance meter has blind spots.

upgrade to a sealed agm battery.

Adding my 2 cents on my experience with gel matted batteries. Several years ago I switched two of my cars and two of my motorcycles to gel batteries. In spite of the expensive price tag, only 1 gel is still good. With the exception of one of my trail bikes, which frequently ends up sideways or upside-down, I went back to the old fashioned batteries with acceptable life expectancy. Interestingly enough, the hyrdo lead plated battery in my Ford truck is 11 years old and still going; the longest one that I've owned. It will be a while before I give AGM another try.

JohnMag makes an interesting comment about volt droppage of old wires. I might create a new topic on that.

[Oz Vision]

one other thing just struck me:  do you know that if you put the key in the bar lock position, & go just a little further, you turn ON the parking lights?  could you be doing this & draining the battery?

Thanks for the comments, I will persist.
My steering locks via a separate lock on the steering head.
Last night I pulled the starter apart. Commutator was quite scratched but cleaned up ok and is still within spec as are the brushes. Did the continuity test - ok.
This morning tried to start it and got slow cranking straight away and no start. Decided to try jumping off a second battery. Hooked it up, turned the key and got an immediate and very loud backfire! That says there was some excess fuel in there, but why would it ignite just from turning on the ignition? I didn't touch the starter.

[Lucky]

My steering locks via a separate lock on the steering head.

? ? ?

[The Prophet of Doom]

Oz, Visions spark once when the key is first turned on.  I've had a few surprises that way - one which came up though the carbs and singed my hair.

I had a very similar problem to you. Traced to spark plug leads.   Resistance does increase with heat, so I figure I must have been just under the limit when cold, just over when hot.  If your bike is 16R model it will have resistor caps at around 5k ohms resistance and should have D8EA not DR8EA plugs
Otherwise zero resistance, and DR8EA plugs

What's with your steering lock? Do you not push ignition key in, then turn it to the left?

[Lucky]

the Vision's TCI uses a 'wasted spark' ignition.  it fires on every revolution, im surprised you haven't heard it go 'phhht' before. it's normal.  dont be holding the plugwire when you turn the key on...

Visions, as Roro stated, lock the steering by turning the key to off, then push down & one position to the left locks the steering (only with the bars all the way to one side or the other)

If you turn the key one position further, you turn ON the parking lights...  very easy to miss in the daylight...

i've never heard of the lock being seperate on the steering head on an Vision, is it possable that when you turn your lock off, it's sloppy due to some modification by the previous owner? perhaps & the lights are comming on & you've just never noticed it??

[Lucky]

one other simple test:

check for a 'draw'  disconnect the battery negative cable & hook a test light (not a meter) between the negative post on the battery, & the negative cable.  have the bike off & the key out.  if the testlight illuminates, then something is "on" & is drawing down the battery.

if so, pull the fuses one by one to isolate the curcit & check from there.  if you pull all the fuses, & the light is still on you might have a shorted R/R, i've seen this happen before (the R/R isn't on a fused curcit, so disconnect it & the light should go out)

[Oz Vision]

Thanks for those suggestions guys, I will get back to it at the weekend. Was supposed to go away on a ride but not like it is, so I will do some more vision bonding instead.
The separate steering lock on the head must be only on the 11U models. I am embarrassed to say that I never used the ignition lock - the key didn't turn when I tried it once so I assumed it wasn't fitted and have only used the one on the steering head. Should have read the owners manual!

[Oz Vision]

.

I had a very similar problem to you. Traced to spark plug leads.   

It must be karma. Just remembered that two sets of Tiger's plug leads are in transit - should be here any day!

[Lucky]

must be aftermarket..?

[Rikugun]

Do all non North American Visions have the lock in the neck?  My pre '70 CL Honda had it there as well as other models back then. Mine had the ignition mounted on the frame under the tank so the neck lock was necessary but why on the Vision?? Curious.

[The Prophet of Doom]

Nope, mine is an '82 16R (Australasian) model and the ignition key locks the steering and flattens the battery just like the US models

[Oz Vision]

must be aftermarket..?

The lock is stock standard on the Euro model. Both steering locks are described in the factory owners manual which is in English, French and German.

[cvincer]

When hot, will it start by bump starting it in 2nd gear?

[Oz Vision]

I had a very similar problem to you. Traced to spark plug leads.   Resistance does increase with heat, so I figure I must have been just under the limit when cold, just over when hot.  If your bike is 16R model it will have resistor caps at around 5k ohms resistance and should have D8EA not DR8EA plugs
Otherwise zero resistance, and DR8EA plugs

so is this correct.. when manual says secondary coil resistance should be 7.9k ohms to the plug cap, it assumes that the cap itself has zero. Add 5k ohm caps as per manual and all up resistance becomes 12.9k ohms. If DR8EA plugs were used, then resistance would be too high?

[Oz Vision]

When hot, will it start by bump starting it in 2nd gear?

It did for a while, but eventually that failed also.

[The Prophet of Doom]

I had a very similar problem to you. Traced to spark plug leads.   Resistance does increase with heat, so I figure I must have been just under the limit when cold, just over when hot.  If your bike is 16R model it will have resistor caps at around 5k ohms resistance and should have D8EA not DR8EA plugs
Otherwise zero resistance, and DR8EA plugs

so is this correct.. when manual says secondary coil resistance should be 7.9k ohms to the plug cap, it assumes that the cap itself has zero. Add 5k ohm caps as per manual and all up resistance becomes 12.9k ohms. If DR8EA plugs were used, then resistance would be too high?

Yes, using resistor caps and resistor plugs will double your resistance and give you very poor ignition.  The result will be similar to that of increasing the plug gap - if the gap becomes too large for the available voltage then the spark simply won't be able to jump the gap.
The reverse is the opposite - no resistor caps and no resistor wire will give you a good strong spark, but it will generate electrical interference which may bugger up the neighbours TV set every time you start your bike (I know this from first hand experience)

Actually I don't think you can even buy non resistor caps these days due to government interference (pun intended).

If you are buying I'd recommend Iridium spark plugs - they have a greatly reduced firing voltage and even though they are a resistor plug, they are lower than copper plugs overall and can work in resistor caps.  I fitted them when the dealer gave me a money back guarantee that I would love them.  I would never go back, they evened my idle out and greatly improved my acceleration.   They are 2-3 times dearer, but worth it, and last forever.

[Oz Vision]

I'm going to preface this post by saying that often times a problem isn't just one thing, but may be a cumulative problem of 2 or more things, especially on a 30 year old bike.  don't discount the 'minor' test results you encounter. the fact that your dropping voltage way down on a hot restart suggests a couple of things.
first, double check your charging system. run the FULL electrex fault finding chart (sorry, Electrosport. i still refer to them by their old name)  don't skip steps. second. don't discount the things you've already repaired/replaced. cables/wires, etc. You have a problem, it has to be somewhere. third, do a voltage drop test & post the results.

Victory declared!
Did the Electrosport test - all good. Had the battery tested at Battery World - all good. Pulled the starter motor, cleaned & refitted it.
Fitted new plug leads, caps and iridium plugs.Dismantled the starter switch, cleaned off the gunk on the contacts and reassembled.
Checked voltage at starter when cranking - down to 7 and 6 volts! Can it be the starter to solenoid cable, it's only six months old? Pulled the cable - at two spots the insulation was damaged due to being jammed against the engine - not to the bare wire, but very thin. Replaced cable - Bingo!!  Went for 300 klm ride (with the bride as pillion), bike started fine every time. Bonus - it is running better than ever! Thanks for all the input.

[Lucky]

it's those silly little easy to overlook things that'll get you every time...
Glad you got it!!

[QBS]

Good on ya!  It is good to win.