cvk34 vulcan 500 carb problem

Ducati got there before you ;-)

 

Yes, I'd forgotten that.

Fascinating. But does it still have cams? The refs I scanned didn't say
that it was a "no-camshaft" engine. Is it?

 

Helluva good-looking engine, that. But what's interesting is that it
refers to pneumatic valve *return* and not *actuation*, which is where
I came in, I believe. And that cam cover *looks* like it's concealing a
conventional DOHC head.

I remember the Honda 1.5 litre turbo F1 engines - the ones from the
Nigel Mansell era - with fondness. 1000bhp for qualifying, and 850-odd
bhp for racing. Utterly incredible.

 

BEER!?? Did you sy beer, just for stupid ideas!?? Just kidding, but I
do have some stupid ideas :>)) ...

If the problem might be fuel related, try isolating the fuel delivery
system from the carbs by connecting a separate fuel source to the
carbs. On my Vulcan 1500, I can dsconnect the fuel tank and/or the
fuel pump from the carbs and feed them from through a rubber or plastic
fuel line from a gas container (placed higher than the carbs). This
would tell you if the tank, fuel tap, or fuel pump (if you have one on
this model) have a problem keeping your carb bowls filled.

Also, my 1500 has a series of switches that keep the rider form
starting the bike in gear, or riding off with the side stand down (both
conditions could cause the rider to drop the bike).
After starting the bike, try reving the engine with the side stand up
and down; in neutral with side stand up and down; in an out of neutral,
pulling in and releasing the clutch lever with the side stand up and
down. IF anything operates out of the normal (other than the engine
dying while rev;d) or mitigates the problem, the combination of swtich
settings may point to a problem with one of these switches or switch
circuit. If so, I'll send you a link to my web site where I have a
write-up on these Vulcan switches, how to test them, and how to
temprarily bypass one or more to get the bike rolling. This write-up
was developed mainly from information I received from riders posting to
this .tech NG (my thanks, you know who you are :>).

Manjo

 

Actually I haven't thought of that. The bike's been sitting in the yard
in neutral with the stand down. Hmm. I might try that this afternoon.

I adjusted the floats to pump fuel into the carbs a little above the
float bowl seal. The bike is still dying with throttle.

So, the last thing I can think of is my air mixture is really really
off. It was at about 2 turns out, I've been reading that a bike that
dies with throttle is running too lean, and to turn the screws in to
richen up the mixture. Is that right, in for rich and out for lean?

Im going to try the screws at 1.5, 1, and .5 turns out and see if there
is any change at all. Its a bugger because I have to haul the carbs off
every time I adjust the screws, they're too hard to get at otherwise.

Thanks again for all the suggestions guys; Im about ready to walk the
damn thing the 8 or so km to the bike shop.