I posted this a few months ago about a problem of the bikes idle dropping when at a stop and the fan running. I originally thought it was a problem with a bad connection of the fan since i basically had to reconnect all the wires on the bike having bought it as a stripped stunt bike. I found the time to redo alot of the connections and checking what I could. When done I started it up and revved it up until I got the temp gauge to 2/3 of the way up and the fan kicked on and it did not do the dropping idle thing. I don't think it is fixed and am thinking the problem could be with the charging system, possible after long rides and having the fan run for an extended time itis draining on the battery or could it be a jetting problem because of my exhaust, almost less than half a yoshi pipe with the bike being ran at a higher temp. for a period of time.The battery is newer,bought it last riding season. I won't be able to truly testit out until it warms up outside. Any ideas would be great whileI have it sitting in the basement.Oh yeah, also I have about 7 to 8 wires that are still connected to nothing that areon an offbranchof the main wiring harness (everythingelectronically works on the bike). Thanks for any help.

 

Choke set too low?
Charging system can't keep up with battery drain? (bad battery or stator?)-Most likely.

 

Don't know how old your bike is, but at idle the bike is putting out very low voltage and will not be "charging" the battery. (at idle i would imagine you will see only about 13v vs the 14+ that you would see while at 4k rpm.) the fan will draw more energy from a system that is not ctively charging at a high rate, so the spark will be slightly weaker. I'd be willing to bet that if you lifted the idle to about 2k rpms that the problem wouldn't even exist. I wouldn't keep it like that, but it will show you that 1,500 or less doesn't produce a lot of electrical energy in the bike's charging system.

 

Mike hit it. You do not really have a problem, you only think you do.

 

also, if you are worried about a charging problem, get the multimeter out.

 

I think he's correct in his statement, but don't leave the idle at 2K. The factory recomneds the idle to be about 12-1500 RPM's The fan will draw alot of current, but I have to say my bike's idle does not drop when the fan kicks on and my idel is set to aobut 1300 RPM's or so. It sounds to me like your stator might not be as up to par as it should be.

 

Thanks for all the input guys. I know what your saying about idle dropping during fan use, but it is a pretty decent fluctuation in rpms when this isoccurring. It has actually stalled out before waiting at a red light. I might have to check out the charging system. Thanks again for the replies.