Topic: Fuel level headache

[Floshenbarnical]

If your purchase from Vintagecb750 doesn’t fit or go together, contact them for a replacement. That petcock should have come with the inner “straw” and a screened in cover that fits over the straw. They stand behind their stuff if it was shipped incorrectly or incomplete. An occasional photo would help.

Honestly, that isn't my experience. Several of my orders have been missing items recently, and numerous emails didn't resolve the issue. So unless it's something I can't find elsewhere I think I'm done ordering from them for the time being.

I bought an M20x1.5 petcock with brass straw and horizontal fuel exit. Hopefully this will clear up my sediment issue without necessitating an in-line filter. I also have OEM float needles on the way, and professionally refurbished identical PD carbs on the way, which allegedly do not have a single stripped hole. Unlike mine, which have all been helicoiled or retapped to 5mm, and I do not have faith that they could carry a tune let alone several ounces of flammable liquid.

These bikes are tanks, I swear. This 750 has had so many problems (all of which I have had solved along the way) and yet it keeps starting up and riding like a scalded dog. Despite the incorrect oil tank. Despite float valves being stuck open. Despite, despite, despite. One wonders what one would have to do to kill it. One does not want to find out.

[seanbarney41]

Starve it for oil to the cam and rockers...seems to be the only thing that can kill em

[Floshenbarnical]

Starve it for oil to the cam and rockers...seems to be the only thing that can kill em

Oh that whole area of the bike is extremely well-lubricated, as evidenced by the patch on my driveway

[seanbarney41]

Starve it for oil to the cam and rockers...seems to be the only thing that can kill em

Oh that whole area of the bike is extremely well-lubricated, as evidenced by the patch on my driveway

for sure....these are tough machines.  But there is a silver bullet for every werewolf...

[Floshenbarnical]

Well you're a bundle of joy mate, cheers for the uplifting words

[Floshenbarnical]

Ok, I’m a dummy.

The petcock I bought has a brass straw for “on” position.

I installed it into the “reserve” hole, so I’ve been running “reserve” fuel through my carbs for 36 hours.

The float needles are stuck open again, presumably with grit.

Question: can I open the drains and just blast carb cleaner through the float needle passages  via the fuel line and then rinse with fresh gas? I think if I have to take the carbs off one more time I’ll die.

[RAFster122s]

Stock screws on float bowls or have you replaced them with socket head screws? You can drop the float bowls and access the floats and float needles from below, just a bit fiddly job. Sounds like you might wish to learn how to work on it from below with the bike on a lift table or a ride up elevated table to give you better ergonomics while messing with the carbs on the bike.
The inner two carbs are a little more fiddly than working on 1 & 4. A good mirror sometimes helps you as well as a small light you can use to give you enough illumination to see your work clearly.
Just don't let yourself get irritated with yourself while you learn to work on them this way. Give yourself some patience and grace. You will find what does and doesn't work. Depending upon your memory you may want to take notes on what worked best and how you did things for later.
Skills are developed, not bought.
So, allow yourself to develop the skills. Something will come quickly, others will not. Keep that in mind. Be realistic about your expectations and ask questions when you get stuck and reviewing previous threads about this work or manuals, etc. Don't bring the ah ha moment to you.

[madmtnmotors]

The petcock I bought has a brass straw for “on” position.
I installed it into the “reserve” hole, so I’ve been running “reserve” fuel through my carbs for 36 hours.

I don't know what this means. There is only one hole that will fit the reserve tube. I would need to see a picture of what you describe.

The float needles are stuck open again, presumably with grit.

You'll need to inspect the bowls to confirm this diagnosis. You'll want to inspect the float needle tang on the floats for divots that might keep the float needle from operating smoothly.

Are you using the filter screen in the tank?

I would suggest removing the carbs one more time for careful inspection/adjustment. I would also suggest setting up a fixture to hold the carbs so that you can "wet soak" them by use of a small fuel tank (I have an old lawn mower tank I use for this) in order to check the floats via the clear tube method as well as a long term soak for leak testing. The fixture I use are two simple metal straps and a short piece of pipe across two jack stands.

[Floshenbarnical]

Bowls are grit-free. Float needles all fully operational. Found the problem

Bloke who refurbished carbs used aftermarket drain screws. Replaced with OEM ones from carbs I had before and problem is solved.

Sadly one of the aftermarket screw heads snapped off 

Left handed drill?