1986 vfr runs but stalls when hot

finely got the bike on the road again but after running around town for an hr the bike just stalls and then starts after resting for 20 min , it snot the battery got lots of cranking and the batt is new , any ideas .

 

Does it just shut off or does it stumble and die? What are your ambient temps?

 

Electrical components such as coils and pulse generators will often run fine when cool and then stop working when they get hot. When the bike dies you need to check for spark at the plug(s).

 

Is your fan working? If not, fix that. My 500 did the same thing when I bought it but after replacing the sensor that screws into the radiator the fan worked again and the overheating problem disappeared.

 

I don't think the OP is having overheating issues, I think he is saying the bike cuts out when it's hot (I am guessing at full running temp and fan is kicking in). Is this correct?

Does the bike not start at all or only after 20 mins when it cools down?

I have a similar issue with my VF500, when it reaches running temp it idles low and when the fan kicks in it stalls (but starts straight back up) I am changing the spark plugs tomorrow. I will update you if that solves the issue.

Rolling Again is right, check your coils too.

I posted a on the forum for my issue, I'll find the link as some of the recommendations may help you too.

 

Here is a link to a thread for my issue:

http://vfrworld.com/forums/showthre...-out-when-at-running-temp-after-30-mins-or-so

 

It is carburation or ignition. Start w/ the easy stuff, and work up to the harder stuff. You can download a free Service Manual for your bike on the web, or even on this site.
You said you got it running recently. Does that mean it had been parked for a long time? Did you put fresh gas in it? Check the carb's? Try turning the petcock to reserve, if there isn't much fuel left. More info provided the better. Are you in Alberta?

 

Don't forget to update your info, bike, location so it makes it easier for people to direct you more accurately.

 

Not a carb problem unless the choke is stuck on. Possibly a fuel pump (if there is one on that bike) failing with heat, but i'm bettin on pulse generators or ignition coil or cdi box.