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

Yeah, those were my thoughts. Too soon for any of this foolishness...

Just went out and started it again. Once again, first time, no choke. Maybe my starting issues are fixed.

 

Today I started it right up and rode around the hood a bit. Cut it off, and it restarted fine.

Pulled it in the garage, and now it won't start at all. Cranks all day though.

It seems to have trouble re-starting after it is ridden, even 2 minutes, lo-RPMs, to a neighbor's house. Ever seen this before?

 

Could this be a hot start issue related to the carburetors? There was an FSB regarding this back in the day.

How long did the bike sit in the garage before you tried to restart?

 

Well, this last time it sat only seconds. I was walking/manuevering it into place while running so I can get the garage door closed, and it stalled out. I immediately tried to re-start, and it never did. In the past few days it always seems to have an issue restarting after I've ridden it a bit (always riding it less than 5 minutes though.)

I just now got it restarted. Pulled the front 2 plugs and saw no spark (again.) I pulled the L side cover off and disconnected a couple of the male/female plugs and re-plugged them in. Nothing. No spark. Then I traced the two plugs down that run from the 2 spark boxes laying horizontal under the seat to their male/female plugs, and disconnected/reconnected them, and tried to start it, and it started right up.

What do you guys use on electrical connections (grease? WD-40?) and where do you get it if it's something obscure? Love to see that FSB if you got it, IC.

Any chance the spark boxes are going on/off from heat or something? Starts OK/better when cold, not so good after running? Ever here of this happening?

What was the cause of the FSB carb recall?

 

Love to see that FSB if you got it, IC.

 

Could be the pulse generators...

 

FSB for 49-state models - I don't have the Cali FSB but maybe this will be of some help.

 

Those are inside the right side cover, right?

 

IC...you have an 84 version. You have any hot start issues or did you do this FSB change?

 

Hmmmm....love to see service bulletin VF500 #5 for '84 CA models...where'd you find this, IC?

 

Your problem sounds electrical. I would inspect all connectors, from pulse generators, to CDi boxes, to HT coils one by one.
Maybe a loose pin could be the cause though connector seems to plug well. Don't forget the power line and associated fuse.
WD40 will do the job but there also are more specialized "contact cleaners".
I would put aside the pulse generators and CDi boxes as suspects. They come in pairs so a fault in one would give an erratic rather than a no-go problem.

 

I haven't encountered this hot start issue but I have read that it can happen.

Sounds like you may have an electrical gremlin though. A can of CRC Contact Cleaner is a good thing to add to the workbench shelf.

Also, do you have a copy of the FSM? This is a must read for VF500F owners.

 

Yes, right side.

 

I've been collecting digital copies mostly through the VF500F Yahoo Group. I don't believe #5 is there but I would post an RFI as someone may have a copy.

 

Yeah...somewhere. I'll lay my hands on it. I got it with my 85. I never thought it would cover the 84 version as well.

 

Should be good to go with the '85 FSM.

Hope all works out with the electrical gremlin(s) - really don't think that there can be too many of these fellas hold up in there. Try the contact cleaner as first step.

 

Well, thanks to Invisible Cities I got a scan of the pulse generator test procedure. (http://vfrworld.com/forums/1st-2nd-...32733-84-85-86-vf500f-oem-service-manual.html)

Today I went out to the bike, turned the key, and...nothing. It has started every day for the past week or so, multiple times per day, without even touching the choke. Fires up on first try. Not today.

I pulled the choke lever, and still nothing. Since I had IC's scan, I decided to check the pulse generator with my multimeter. #2/4 came in @ 360 ( should be within 315 and 385) and #1/3 came in @ 359. So I'm calling the pulse generator working to spec. I was thinking my issue was more of a hot start problem, but going by today's troubles it's not. In the past it's only given me non-starting issues after riding it for a while. Apparently that may have been just bad timing since today it was cold.

And then, after I plugged the pulse generator harness back together, it fired right up on the first try. I checked all the pins and clips within the harness, and none seem loose. All connections are clean, as they should be...this bike hasn't even seen the sun in 26 years, much less any electrical connection-affecting moisture. I guess the next thing is to pull the right crankcase cover and make sure all is in order on that side and nothing is loose.

 

Are you checking for spark? The problem you are having is not typical of pulse generators, so I wouldn't spend any more time investigating them. If you are getting spark then it will run (or try to run). That's an easy check at least.

I'd check the main fuse first. They can separate with just a crack, leaving enough contact to pass enough current to crank the engine over but not enough to drive the ignition. It's not terribly common, but it's happened before. It seems that bikes that have sat lot are afflicted by this.

 

Glad to hear that the pulse generators test out to spec.

Sounds like this gremlin is a bit of a trickster. Before removing the right side cover perhaps give a go at inspecting all the ignition related components and connectors.

On this note, a can of CRC Contact Cleaner would be a good addition to your next hardware store run.

 

Yeah, I check for spark every time it won't start by pulling out at least 2, sometimes all 4 plugs. And I then hit the starter and I don't see any spark on any of them. Then I usually plug/unplug the 4 or 5 block connectors under the left cover, and then I get spark. I've narrowed it down so lately I've not been pulling the plugs, and only unplugging/plugging the topmost black connector that goes to the pulse generator. And today when I did that and hit the starter, it fired right up. I rode it around my neighborhood for about 5 minutes, cut it off, and 10 minutes later a neighbor walked over and wanted to hear it. So...of course, it would not start this time. I pulled the cover, went right to the pulse plug again, unplug'd/replug'd, and it fired right up.

I checked the main 30 amp fuse a few days ago when I checked the other fuses under the key cover, and the main fuse was fine. But, I should check it again if it can get hairline cracks like you said and still work. I'll do that tomorrow.