85 VF500 idles low and cuts out when at running temp after 30 mins or so

Hello. I am new to riding and my VF500 is my first bike.

I have noticed if I have been riding for about 30 mins and when the temp needle reaches the middle and above the bike idles low (around 900-1000 revs), when the fan kicks in it sometimes cuts out. It will start right back up with a little gas.

Other than that, bike starts up no problem and rides fine, no sputtering, no jerking. When the bike normally idles before the fan kicks in its at 1200.

Like I said I am new to the bike world and learning as I go. Any help or advice would be great

Thanks

 

Check both the charging system and your battery - those would be my first places to look.

Then I would check the wiring for the fan to make sure it's not grounding out / shorting somewhere it's not supposed to.

 

Thanks, I will take a look this weekend when I have time. I have a volt tester somewhere

 

Do the Drill, then you will know what is happening with your charging, it seems when the fan kicks in it loads up the motor causing the revs to drop. Read post #9

http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures

 

you need to boost up the idle speed with the knob provided for that purpose. Stalling after operating temp is reached is a classic sign of failing pulse generators or ignition coils. Be sure to check for sparks as soon as it quits.

 

Your tickover seems a little low at 900 to 1000 rpm, it should be at around 1300 rpm, i'd set that a little higher before attacking anything else.

 

The OP said the bike idles at about 1200rpm but it drops when the temp comes up, it usually works the other way, revs increase once the motor has warmed up, not drop. To me it seems like the battery is weak and it is relying too much on the alternator once the fan kicks in