New 84 VF500 with some problems!

Hi everyone,

I'm new to bikes -- had to sell my old love, a 1990 Mazda RX-7 TII, because it was too impractical w/gas being so high -- but am loving my VF500.

It's got some problems I'm struggling to pinpoint, however, mainly because they don't necessarily occur in any seeming pattern. Any leads on something that links the issues together, or problems to check for, would be greatly appreciated.

1) The idle is sometimes far too low, to the point where it will die if I don't hit the throttle, regardless of how much choke it has. Conversely, if I run it enough, sometimes the idle will be as high as 3K RPM. But minutes later the idle could drop and it'd die anyway. About half the time though, the idle is fine.

2) I assume this is related. Sometimes the bike will just die if I come to a stop while riding -- it's also more likely to die of a low idle when it's doing this, too. When I approach a stop I have to rev it a bit to keep it from dying. Not always, though, just SOMETIMES. Sometimes it'll do it after being run hard, sometimes after being run lightly, and sometimes not at all regardless of how it's run. It's a minor inconvenience, because I don't have to gas it that much to keep it from dying, but it doesn't instill much confidence in my bike.

3) If I haven't ridden it in a few days, and try to start the bike in first, it will lurch forward even though I'm pressing the clutch. Naturally I'll press the brake to stop it from going when I don't want it to, and it'll die. Repeat this process once or twice and the problem disappears. Oil change necessary? I finally found a filter and got some oil today.

Thanks..

 

1) You need your carbs synched. One or more carbs is wanting to rev different from the others. This causes the idle to "hunt" when stopped.

2) See #1

3) You need to bleed your clutch. It's not releasing the clutch enough.

I start mine in neutral and put on my gear while it warms up on choke. After it can idle without choke, it is sufficiently warmed up. (If you can idle immediately upon starting a cold bike - without choke, you definitely need your carbs synced)

Shifting into first on a warm bike does not lurch as much as shifting into first on a cold bike.

P.S. Get a manual if you don't have one.
P.S.S. Make sure you get either motorcycle specific oil, or use non-synthetic without "energy conserving" in the oil seal.

It has friction modifiers that will make your clutch slip.

 

Idle Problem

Hey there,
I just got an 86 VF500 as well. The reving up to 3000 and staying there when you give it gas is bc the choke is probably on too much. I also have the same problem with the idle being low and having the bike die out on me at stops and if its just idling in the driveway. Id like to know what the problem is too...:unsure:

 

To test if your choke is closing enough, push in on the brass choke valve.

If it goes in at all, then the choke cable is too tight, the linkage is rubbing or the brass valve needs to be cleaned. Even a tiny opening of the choke can effect the bike.

 

Thanks mason, I was afraid that was the issue :/

edit: then again, that's probably the best of all possible problems, haha. I'm just used to EFI and this will be my first experience with carbs, but oh well, never hurts to learn.