No Fuel?

[Anthony]

Well 5 minutes of 5-10 seconds of cranking. Basically fiddling with it for 5 minutes to try to get it to start, not constant cranking. How else am I suppose to do it? If it won't start, how do I get it to? Maybe now that it ran for 5 minutes, it will start like normal the next time I start it. Will a hose in a gas can that is at stock level work, or will I still need to do an IV method?

 

[Grimly]

If you put the tank on a table at the right height, that'll do. If your float valves are seating properly, they'll withstand a much higher head of fuel than the normal fuel tank height in any case, so I'd be inclined to look more closely at them. You did replace them?

 

[Anthony]

No I didn't replace my float valves, nothing was wrong with them at the time and visual inspection indicated that they were fine. I didn't read anywhere that they should be replaced when re-building. Steve said that placing the fuel higher can overload the valves and then it floods the engine, which happened in my case, so I guess that's suppose to happen.

 

[Grimly]

No, it's not. Put it this way, a typical float valve of that type was perfectly capable back in the day of sealing off a low pressure fuel pump of 5psi, which is about the equivalent of 10ft of head - and more besides. Either your floats are wrong or your valves are.

 

[Steve]

Steve said that placing the fuel higher can overload the valves and then it floods the engine, which happened in my case, so I guess that's suppose to happen.

No, I didn't mean that it's supposed to happen when you do that, only that it's more-likely.

Keeping the fuel height closer to stock levels minimizes that possibility.

.

 

[Anthony]

Well it keeps flooding. I left the fuel IV at stock level and it still flooded it. So then I did the gas can again, and it worked for a couple minutes, idled at 4k, and died. Did this twice. Cleaned the plugs again, and put the pilot screws at 1 and a half from lightly seated. Now it won't start at all. I'm getting very frustrated, tonight was one of my few nights off to do testing, and I can't even get it running to do a carb sync and adjust the pilot screws properly. And I also am having a hard time with the master idle screw, as I can't see and don't know how far in it is. Can anyone help? :/

 

[Grimly]

If your float needles are letting too much fuel past, you can fiddle and fart around till you're blue in the face, but you'll never get a stable condition.
Not the first time an owner had visually inspected needles and seats and thought they were fine (me too, and I used to do it for a living) and the only cure was a new one/set/however many needed.

 

[Anthony]

So I set the pilot screws at 3 turns out, and it still is not starting. It's acting like it can't get fuel, but if I do a fuel IV, it just floods everything.

 

[Anthony]

Also, if it is my float seats or valves, how do I know? What should I all replace to be safe?

 

[Grimly]

If they're all brass on the needles, they can be lapped in, but not too much. If there's a Viton rubber tip, that's ruled out. The little spring on the end often goes weak, too. As for the floats, if they're not leaking, they're probably ok, but check them carefully for distortion and bent or cracked/weak tangs where they bear on the needles. The floats should be a nicely loose fit on the securing pins so they don't stick.
There you go.
It's perfectly possible to check everying out and it still leaks, and the only cure is new needles and seats - they must always be replaced as a pair, never individually.

 

[Anthony]

Are the float needles the ones that sit inside the float inlet seats, and the floats sit on too of it? I guess I should replace both the float needle and seat? Only thing is that they never did this when I had it running before the rebuild. Is this common? And I tried the IV once again, just a little fuel, and it flooded into the airbox once again. ARG!!!! I'm done for the night. What should be my next step?

 

[Anthony]

Also, my float inlet seats have vitron o-rings from Robert Barr. So does that rule out the inlet seat, but possibly still be the needle itself?

 

[Crankthat]

I have read here of people rebuilding there carbs with new gaskets and the floats getting hung up on the gaskets.
That could be a reason they are flooding.
The solution is to open the bowls again and carefully trim the gasket where it would be needed.

Might be a stupid question on my part, I have been racking my brain trying to figure out what is going on with your bike.
I am not even sure if missing this part would cause your symptoms.
The ones pictured location circled in red are from a set of 81 750L carbs waiting for me to rebuild.
The plugs pictured on this set are old and need replaced.
Are the rubber plugs circled in red on your carbs?
These carbs still need everything pulled and a dip.
I only attached the gasket to show you where the problem may be.

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You will notice a few extra colors in the above photos.

The first picture circled in dark blue.
A flat rubber circular ring belongs over that recessed area.
The recess is actually a metal plug.
Now and then someone looses one of those plugs.

Not to be mistaking with the rubber plug circled in red.

In the second photo once again you will see the area circled in red where the rubber plug belongs.
The rubber plug is removed in this photo.
Marked with light blue you will see another tab that is attached to your float.
Very rarely this tab will get tweaked while rebuilding.
It would take a good bit of force to bend this tab to a position you do not want it in but it is a possibility.

In the third photo you will see the colors marked same as above with white this time around the left side of the gasket and float.
This is just to show you how close the gasket is to the float.
If the gasket sticks out from the sealing surface of the body and bowl it may swell a bit with fuel.
Your float may hang up on it not allowing your valve to seat into mating surface.

I know firsthand as many of us do what a pain in the crow it can be to remove and reattach carbs on this bike.
Trust me when I tell you you should be glad it is not a 550 or 650.
After removing and reattaching a few times you will be a expert at it though and it will get easier and less time consuming.

Go ahead and take them off again check everything listed above and your float height again.
The pictures in the tutorial can be a bit confusing when checking the float height so give it another look to make sure you are doing it right.

Somewhere there is a thread on checking float height with carbs off bike and hoses attached to fittings on bowls and swept upwards so the fuel will not leak out.
If you have some extra hose around find the thread.
Even without fittings to hold hoses in place I am sure you can come up with something to block off any seepage of gas from a small clear hose jammed up the bowl drain screw/bolt hole.

What you will be trying to do is sweep the hose attached on bottom of bowl up past the top of bowl so you can see at what height the fuel stops.

I will try and see if I can find the thread.

 

[Crankthat]

While searching for the above indicated thread I came across this.
http://www.thegsresources.com/_foru...-rubber-plugs-in-carb&highlight=bowl+fittings
And this.
http://www.thegsresources.com/_foru...a-spec-for-float-drop&highlight=bowl+fittings
And this.
http://www.thegsresources.com/_foru...-Float-height-trouble&highlight=bowl+fittings
All good reading.
I cannot seem to find the thread I am searching for though.

 

[Anthony]

Thank you for all your help crank, I will get into the carbs again once I get some time. I just have been worn down recently and need the energy and willpower to get my carbs off and open again. I will check all these things and also report back with results. I just hope I can get this fixed, and not ware money on the wrong things.

 

[Crankthat]

One more thing.
On your needles.
The little pin that the float tab pushes against.
There is a spring inside it.
The movement of that must be good on all 4.
They must be able to move freely in/out without any hangup.

Ok two more things.
http://www.thegsresources.com/_forum/showthread.php?147153-Float-height-trouble&highlight=bowl+fittings
And be sure to click on the link in Larrys post #6 on that thread also.

Sometimes you need a break from wrenching to clear your head and go back to things with a more positive outlook.
Some days just a hour or so will do.
Some times a week or two is needed.
We all feel the pressure of wanting to get the bikes on the road and for there first real ride.
While working on these things the pressure we put on ourselves can be rather high.
We forget to spend time doing other things that bring us the mental relaxation we need in our lives.
When money is a issue we spend it all on the bike without the immediate results we crave.
This adds to the pressure we feel.

Take a weekend off and find a pretty girl to hold hands with.
Break out the rod and reel and lay down by your favorite fishing hole in the sun and relax.
Grab a dog and camera if you have one and follow it up in the hills for a afternoon.

Most important just find some Anthony time and spend it not thinking about the bike.

 

[Anthony]

Great resources Crank, I greatly appreciate all this. Here is what I'm going to do. I will take a video of the issues I'm having with starting it/fuel/flooding of engine. I want this recorded to show on this thread to see if I'm doing something wrong first. Then, if we decide the carbs need to come off, I will do so, with a video of the inside of carbs and floats in action. I can also provide pictures. I feel these are the best steps to take, and just need to do one thing at a time. This can be hard to diagnose, but I want to make sure it's not a USER ERROR :stupid: Do you believe these are the best steps to take? I also no longer have the help of my dad who will be gone for another 8 days, so anything I do is on my own. He has been my main resource on this project, as he owned an 83' CB1100F back in the day, and knows about these Jap bikes pretty well. But then again, he has forgotten a lot, and that's where the bountiful source of information from here comes in handy! Also, hands on experience with troubleshooting is a must for me.

 

[Anthony]

Another thing, is the vacuum port suppose to be plugged off when using a fuel IV (bottle) setup? Mine is not, and could this be causing my issue? I just thought about this, and want to make sure I think of everything before pulling the carbs and spending money

 

[huntb]

Another thing, is the vacuum port suppose to be plugged off when using a fuel IV (bottle) setup? Mine is not, and could this be causing my issue? I just thought about this, and want to make sure I think of everything before pulling the carbs and spending money

Yes. You will definitely need to plug the vacuum line. I use a golf tee. Not sure if this would be causing your problem though. Try it and see

 

[Anthony]

This might fix my issue with the engine racing at 4k and I couldn't adjust it. But, my float needles might be stuck, so I will also try using a rubber hammer on the float bowls to try and "re-seat" them. If this doesn't work, off they come, and I will double check the float height and make sure they are seating and working properly.