It's official. I'm a VF500 addict.

Yep, I ran out of propane tonight on the grill, so I'll add it to the list for tomorrow.

 

I assume you've tried wiggling and prodding this area while the bike is running?

 

Yep, I just tried doing that again, and it never cut off.

I also double-checked the main fuse. It's still in one piece and looks good.

 

Have you taken apart and cleaned the kill switch/start button? Do you have headlight when it won`t start? Ignition switch?

 

Good idea. I have not R&R'd the kill/start switch yet. When it won't start, it is DOA all around: no crank, no headlight, nothing. Like suddenly the battery is missing .

I've already checked the condition of the battery itself, and the contacts on it. All are clean and dry.

 

Main switch then?

 

In post #62 you mention that the bike 'cranks all day'.

I may have misunderstood. I thought the issue was that after running the bike and turning off - when you try to re-start the starter motor will turn the engine over but the engine will not start. Is the incorrect?

 

No Headlight, no nothing I would pull the ignition(key) switch,pop the plastic cover off the bottom(watch the springs and ball bearing now!), clean the contacts, regrease and all back together. Do the kill switch/starter buttons also.

 

Well, the fault is with me, not you. I wrote that last part wrong. It had been a while (4-5 days maybe? I start it during the day maybe 3-4 times) since it would not start after riding it a bit, and I forgot exactly what the symptoms were since it's been a while since it has had the starting problem.

And when it DOES fail to start, I have the side panel off and have it re-started by doing the plug/unplug of the pulse generator connector so fast I guess I just do it on auto-pilot now without clearly remembering what the symptoms are.

But I was right the first time: When it fails to start, it will crank all day without starting. There is no spark that I can see coming from the plugs themselves, as in the past I either remove 2 or 4 of them to check. Then, after R&R 'ing of the plug, it fires right up. All the numbers on the multimeter tell me the pulse generator is fine.

I'm hoping it fails to start when I have my multimeter handy to check the pulse generator again right at that very moment. I'm wondering if it's intermittent b/c of heat or something.

Thanks for paying attention, IC. I should have been more closely!

 

It sounds like you are getting close to resolving this issue - the PG appears to be the trouble maker here.

 

What a bizzare issue. I really don't think the pulse generators are the problem because the unplug-plug process would make no difference. It almost sounds like something in the electrical system is getting latched and unplugging that circuit is what resets it. The electronics are not that sophisticated, so I don't know how likely that scenario would be. I hope you find something because I would like to know what is causing your problem.

 

How about swapping the PG and any other part you want to test from your other bike and giving a go?

 

A top notch idea - a great benefit to having two VF500Fs in the stable.

 

Check the pulse generators when the bike is hot. Compare to previous cold readings. Pulse generators may measure fine cold but show a fail when hot. Been there.

 

That makes two of us. It happened again yesterday.

Started it in the afternoon heading out for lunch. Started right up, first touch as always, no choke. Moved it maybe 500 feet, and got caught in a conversation. Cut it off. Talked for less than a minute, and...it would not start again. I was thinking it was the key switch (since that had not been tried), so I flipped the key around all kinda ways, cleanly turned the switch back and forth a dozen or more times, tried my other key...nothing. All it did was crank...like I had the RUN switch turned to OFF by accident (though I didn't). I cranked it and cranked for a while, moving all the switches off & on, thinking it was a bad contact. Nothing. Walked away for 5 minutes, made a phone call saying lunch was a no-go, walked back, turned key, fired right up and ran.

Brought it home at the end of the day after a 10 miles ride home, pulled into garage, cut it off, waited a sec, tried to restart it...nothing. Crank, but would not fire, as usual. Went inside, removed gear, cursed a good bit, came back out a few minutes later, and it fired right up, first try. I cut it off and on @ the key 5 more times, and it restarted each time immediately.

 

Yeah? You mean once it's running/been ridden a while? I have not tried that method. Interesting idea. I never thought they would change once they were hot....I guess some kinda open circuit when heat is applied. Hmm. You replaced yours after getting different readings I'm guessing? Did yours show a change after riding, or just after idling/running, or both?

 

I have read that the pulse generators can have this trait - that they will start to show signs of failing when the engine is hot before completely giving up the ghost.

The FSM notes to check these cold but it would be interesting to see what they read when hot. I am not sure what the hot spec would be but perhaps you can jot down the various readings in a log to see if there is a pattern.

This is one devilish gremlin you have wg!

 

Don't I know it. If it DOES happen to be the PG, it only lived less than 2500 miles. Not one for the record books...

 

Mid-Update:
Started the offender over the weekend and rode it a bit. Cut it off. Figured..."What the heck...I'll try and restart it now." I hit the starter button again.

And...nothing.

BUT I DID see the ever-so-small slight puff of smoke come out from the starter button module around the button itself. The wispy bastard hung in the air for a second, just to rub it in, and disappeared.

And yet, a second was all it took for me to be on to you, you non-starting Fokker.

I haven't taken the module apart yet, but will this week sometime. The only thing I have ever done to the L&R bar modules is spray some WD-40 on the left one when the high/low beam switch was sticking.

Perhaps time and non-use was not kind to you, O Right Starter Button Module.

Alas. This fares double-badly for you, for when I get the time, I shall not be kind as well. This I promise you.