Petcock Valve clogged?

So I've had my gas tank off my bike for about a week and a half because I was working on patching rust pinholes on my tank.

The bike started fine before I took the gas tank off last week but now, after I've fixed the tank and put it back onto my bike, it doesn't start anymore! I think it is because gas isn't reaching the engine. The bike sounds like its trying to start, motor sounds and all but it doesn't reach that vroooom part.

I've completely confused myself as to where the smaller diameter tube plugs into. Does it plug into the opening right across the gas tube's opening, or the one right across the petcock valve (on the outside)?

Also, when I have my tank off, and no tubes connected. I turn the petcock valve to ON or RES and no gas flows out, is this normal? I vaguely remember there being some requirement for a vacuum?

I have at least 3-4L of gas inside the tank, so it should be enough but if you're aware that it isn't... that would be good to know too, haha.

 

The petcock has a vacuum safety feature:

 

The skinny vacuum tube attaches to #1 in this photo:



Make sure the other end is solidly attached to here:



....and that there are no tears in the line.



When I popped open my '86 Petcock I found no strainer....but I found lots of gunk in there.

 

Thanks guys!

In hindsight, I might only have less than 2L of gas in there. Not really sure anymore.

I think I'll open up the strainer cap and check out what it looks like in there.

So if I turn the petcock valve to ON or RES, do I need to apply a vacuum to #1 for gas to come out?

And I just noticed, my #1 points in the same direction as #2, haha.

 

Please take pictures if you do.

Yes. I tested this by attaching a vacuum tube to that nipple (#1) and sucked on it (bring on the jokes )
With the Petcock on the tank with gas in it I was able to get some fuel to come out of the main outlet.

That may be the way it's supposed to be. I have no idea if it matters or not

 

Yes, you must apply a vacuum to move the diaphram and allow fuel to pass.

 

So I took the cover off, here is a picture of the catch and the filter. They're both clean as a whistle...


I tried applying a vacuum to the nipple #1 while the valve was set to RES and nothing came out. Actually, I couldn't even suck anything. How hard should I be sucking?

I'm going to wait for my dad to get home with a full jerry can and see if its because there wasn't enough gas...

 

So I put more gas in, and the valve works when I suck at the nipple.

However, my bike still doesn't start. =/

I tried putting maybe around 5mL of gas into the gas line before reconnecting the gas tank to make sure there was some gas in the bike. But I'm not convinced if it is enough or not. It has been sitting for about a week and a half so all the gas inside might have evaporated. However, it shouldn't be too much of a problem? Not sure. Should I put more gas in first into the bike or? Because I don't want to drench the spark plug although that is probably pretty hard to do.

If I should put more gas into the bike before I start it (assuming all the previous gas evaporated off while sitting there for 1.5 weeks with the tube opening covered with paper towel), how much should i put in?

As for the sound of it starting, I can hear the boomboomboomboomboom and tatatatatatat. It's just lacking the vroom.

Is it possibly my spark plug committed suicide over the past week and a half? haha

 

Good news! I waited maybe 30min cause I had dinner. Then I went to try again after dinner and it starts! Yay! =D

 

Good to hear!

This is all with an 86 tank and Petock?

When I took apart mine there was no rubber o-ring OR a filter

 

Well, I did get this bike 2nd or 3rd hand so I'm not 100% sure if its an '86 tank and petcock. I can take a picture of the tank on the bike since I've put it back on and show you. Although I'm not sure if that will help, haha.

I have the repair manual and in the book, it has the same pic as the one invisible cities posted and the strainer part pretty much followed that pic.

Maybe yours was taken out and not replaced from your previous owner?

 

Photo of an '86:

 

Yup, that's what mine looks like besides some colour differences and that big sheet of aluminum or whatever it is. How different does an '85 or '84 look?

 

The tank is the same. Just the petcock and it mounting is different.

The sheet of aluminum is the heat shield.

I was thinking that. After you post I know that for sure now.
Thanks for your pictures. :smile:

 

My guess would be yours is the '84-'85 version. Mounting plate axis is around 20degrees to handle axis, mounting bolts are 8mm, fuel out pipe is 8~9mm.

 

Hmm... heat shield eh? Maybe I should somehow install my own...hahaha.

Next time I take my gas tank off, I'll be sure to take pics. But for now, it looks very alike to slowbird's. The position of the petcock is the same. =)

 

Here is another view of the '86: