Bike runs, but not with vacuum hosed attached to gas tank.

[EMPbarker]

Hi.

I have been working on my gz for several days now. I adjusted the valves, they seem okay, a little noisy, but otherwise fine.
The bike had a hard time starting.
It starts though. I just drove it around the block a minute ago.

Number one: The problem, is that I ran it without the vacuum hose attached to the tank. The bike was only running off the fuel in the float bowl. If I hook up the vacuum line, it kills the bike, almost immediately. Like, bang - dead. And won't start.

Number two: Let's say i have the air filter out, and I turn on the primer on the petcock, in a few seconds, gas will start to flow slowly into the air box. Should this happen? Should not the floats in the float bowl turn off the input of gas?

I'm really at the end of my rope here.
School starts after this week, so If I don't get it fixed, I'm screwed, and riding the bus.

Looking forward to your reply.

[Easy Rider]

Originally Posted by EMPbarker

Number two: Let's say i have the air filter out, and I turn on the primer on the petcock, in a few seconds, gas will start to flow slowly into the air box. Should this happen? Should not the floats in the float bowl turn off the input of gas?

Numbers one and two have a common cause.

The float is not "floating" or the float valve isn't shutting off. When you connect the vacume hose, gas starts flowing and the float doesn't stop it when it should ......resulting in flooding the engine. This is similar to what happens in the PRIme position.

The gas shouldn't go into the airbox, as I'm pretty sure there is an overflow pipe in the bottom of the carb. that it should run out of first. It may be going there too and you just haven't noticed.

[Sarris]

ER is correct. The float ain't floating. Sounds like it (the float) may be stuck. Take a wrench and rap the bottom of the carb (not too hard) a couple of times. This may free it up if it's stuck. I have seen the occasion where when the carb is run dry, the float will go to the bottom of the bowl and stick. Put the petcock in the prime position for about 30 to 45 seconds, then put it in the run position. See if it runs. If not, rap on it again while it's in the prime position. Again, see if it runs. If so, the float was probably stuck. If you get it running, put some carb cleaner in the gas tank (Seafoam is good). If not, it's off to the shop.

This may get you going. Good luck.

:chop:

[EMPbarker]

i took off the carb.
i opened the carb.

the very tiny, looks like a missile warhead, piece,
with a rubber conical head,
which is connected to the floats,
so that it inserts into and blocks
a small hole, which allows gas into the float bowl,

i cleaned it, and tested it.
And put it back together,
and replaced the outer bowl screws with
some allen keyable machine screws,

bike runs good.
valves still a little loose and noisy.

[jonathan180iq]

Is that a poem?

[Easy Rider]

Originally Posted by EMPbarker

valves still a little loose and noisy.

If you adjusted them, why are they "loose"?
Even when adjusted perfectly, you will hear a little valve noise........sometimes a lot.
Your bike is talking to you. Learn the language and then tune her out........like I do with the wife !!! :oops: :lol:

[EMPbarker]

when the bike came from the factory,
i left the valves alone,
it was pretty quiet.

20K miles later,
I checked them,
The smallest feeler gauge wouldn't go through.

Nothing melted, just tight.
I checked all that when I put a new head gasket in.
Cause the bike has a hole drilled,
From the factory,
Where it shouldn't.
It compromised the Head Gasket,
But that's another story.

Now that the valves are adjusted, just right,
Or at least to within specifications,

They make quite a bit of noise.

It makes me want to open it,
And tighten them down again.

Not sure what to do.
Tune it out?

[jonathan180iq]

Free verse, right?

[Easy Rider]

Originally Posted by EMPbarker

Not sure what to do.
Tune it out?

Yes, if you are SURE you did it right.
A double-check wouldn't be all that hard........or find another GZ rider and compare.

[patrick_777]

Originally Posted by Easy Rider

Yes, if you are SURE you did it right.
A double-check wouldn't be all that hard........or find another GZ rider and compare.

+1 for advice.
-1 for prose style.