First Bike, '86 VF500F

On my VF500 I disable the petcock vacuum function so that it operated like a normal mechanical valve. You can also use a tool, made for bleeding brakes, to pull a vacuum on the petcock and get the fuel moving. It is like a small hand powered, suction pump.

 

She lives! After another hour of screwing around I got some fuel to feed into the carbs and she started right up. Let's just say I used...human air power to draw a vacuum out of the tank.

She'll sit and idle without any choke on now, which is what I set out to do. After sitting at around 12-1300 for a good five minutes, I gave her some throttle, and the idle then steadied around 3.5k and didn't drop again. So my thoughts are: the carbs really do need to be balanced, or I don't have proper cable tension on the throttle. I think I'm going to try to address both. Any more suggestions? There are a ton of threads about fast idling so I have a lot to try.

Also, I can't say how excited it made me when she started up again!

 

I'm just going to flood this thread with all my thoughts while I do my own research...

Took her for a spin around the block and by time I got back there was smoke pouring off of something on the bottom of the bike. Looked to me like that oil leak was dripping directly onto one of my exhaust pipes and burning off like crazy. I had a look under the bike and realized that the area on the left side near my clutch and shifter is absolutely caked with what I assumed is oil. Most of it wipes right off. I'm going to try to address this leak while I have the carbs off again... any ideas? That oil line that the PO told me about is one option. Where else could (common) could it be?

 

The engine must be clean to find an oil leak. Remember that "down" is where the oil ends up and not where it is coming from. A little oil makes lots of smoke on hot pipes. Clean the bike thoroughly, start it and then look for leaks. In extreme cases I have used a can of spray foot powder. Clean the engine and get it dry. Spray a coating of foot powder where you think the leak is and then start the bike. You will see traces of oil in the white powder. The powder wipes off.

Most oil banjo fittings do not leak but valve cover gaskets are prone to leakage. Your shifter seal might be leaking and you might have years of chain crud built up in that area masking a counter shaft seal leak. The list of likely leaks is endless on an old bike.

Make sure your cable routing for your carbs is not binding.

 

Here's another observation: after a fifteen minute ride she was *very* close to "H" on the temp gauge. I attribute this to the fast idle.

I'll be parking her in my buddy's garage on Sunday and have a whole list of things to try...and I can't wait!

 

on the fast idle. someone may have monkied with the mixture screws. there is one on each carb, turn them in till they stop then back them out 1 and 1/8 turn.

when I got my 500 the carbs were gunked, instead of cleaning them properly the PO "adjusted" them. mine did the exact same thing when I cleaned the carbs


I'll run out and take a pic in case your not sure which screw.

 

That is the front left carb. Also check for vacuum leaks. They can cause fast idle as well.

 

I'm pretty sure they've been messed with since there's no cover over the screws. Is there any merit to disassembling the mixture screws and cleaning the assembly out? I was thinking of doing that anyway since I'd already have the whole thing off the bike.

 

yes and no, if they are REALLY gummed up but if the bike is running the passages should be clear.

I wouldn't with them on the bike.