Hi guys, Got myself a VFR400 a few months back. So far I'm loving it, plenty of power for my level of riding. It was a jap import only 21,000kms on the clock, and had a full engine rebuild 5,000km ago (previous owner). I had it fully serviced about 2 weeks ago, they changed all fluids, balanced the carbs etc.. However just recently I was riding a short distance home, I was taking it easy and keeping the revs pretty low. It was all going fine until I tried revving it over 5k, it just had this huge flat spot and wouldn't rev properly. Few hundred meters later it sounded like a tractor and had no power, I had to pull over and take it on foot. At first I thought I'd blown a head gasket, but now I'm thinking it's a fuel problem. On the opposite side to the fuel on/off/reserve switch there is a small cylinder which seems to have a vacuum line attached to it. I started the bike and pulled this line off and it started revving perfectly again. There are two small pipes coming out of this cylinder and attaching the vacuum tube to either one didn't seem to make much difference, it was idling fine. So I rode the bike home, but now I can't even get it to start. Anyone have any ideas what it could be? Sorry for the long post.. and I appreciate anyone who bothers to read it.
on my vf500 that vacuums tube sucks and makes gas go into the carb your bike will still run while your carb is full of fuel attack it and try the starter for about 10 seconds it should refill the carbs and if not put at least another gallon of gas into the tank. other then that its a rare bike I wish I knew more. I have had to pull the carbs off mine about 30 times not I think I might have a leak in the seals although its still rideable and runs fast it idles funny. dont work on anything that rubber in the cold it will break.
