Trick float

[DGXSER]

Ok, As most of you already know, I just rebuilt my carbs. I had them on the bike for a few days, took a ride, took a spill. Nothing to serious, just slid off the road and nice easy lay down in the grass with back tire sliding out. I just got my pride injurred.

Since then, I had to realign the front end, straighten the handlebars, and do some body work on the healdight back box and the front turn signals. Don't think this pertains, but wanted to give all information.

Now the problem, I have been fusisn with fuel line routing and then last night I got a flooding of the no 4 carb flowing out the air box. Took the carbs off, opened no4 float bowl, pulled the float and valve, made sure everything was clean, and even trimmed the gasket to be sure. did the open float bowl bench test. Passed with flying colors after an hour of sitting. Put the bike back together. Turned on the fuel and let it sit. after a minute or more, no fuel from the air box.

Started the bike, let it warm up to where I had the choke off. Was putting the seat back on to take for a test ride when I noticed black smoke from the right side, look down and no 4 is AGAIN leaking through the air box!!

Am I missing a step here, something I need to check or set differently. I never had this problem till I rebuilt the carbs, now it keeps going and coming and going and coming again.

[Ken Talbot]

How was the o-ring that seals the float valve into the body of the carb? Any chance it got nicked during reassembly?

[DGXSER]

Ken, I got a new seat assembly with the kit, o-ring on it when it shipped along with new screen. The carbs were on the bike for a while with no problem after the rebuild. In fact, no 1 did this at first, but not after I bench tested.

I will pull the seat to look in the morning though.

[bikerphil]

Dgxser, try tapping on the carb bowl with a screwdriver handle or such 'n see if the float is sticking. Sometimes they drop too low and get stuck. This can sometimes happen after the carb bowls have been dry. If this is the case, there should be a tang on the float that will prevent it from dropping too low.

[oldyam80sg]

Just curious -when you dropped the bike -did it shut off?

[DGXSER]

Oldyam, Yes it shut off. Electrically it was dead when I picked it back up because the headlight got pushed sideways and the back box cut the wiring harness where the main harness comes in, the red and yellow wire got cut in two and a few others got cut into including the brown wire which blew the main fuse. I spent one night cutting and splicing wires, soldering and taping the splices and then taping the rubber covering back in place. Yes, I used electrical tape, not duct tape or masking tape as I have read other PO's have done.

I tried tapping the carb float cover with a screwdriver before I pulled it. Just kept losing fuel through the air box.

I pulled the float seat and the o-ring looked fine. I rechecked my float heights and all look good. Later today I will do a bench check upside down and open, then upside right with float cover bolted on before I put them back on the bike again.

Thanks for all the suggestions!

[tarzan]

Sometimes the gasket will have a little material sticking inside the bowls.I have seen where guys have had to trim the gasket a little.This little tiny bit of gasket material sticking inside the bowl can be enough to snag the float when the level drops ,keeping the float from coming back up and closing the needle and seat.Also if your floats are not straight and level side to side it can throw things off.Is the float drop adjusted so the float doesnt drop too far?There is a tang to adjust for this also.

[ccogswel]

Just a thought.

But you may want to check that the float isn't hanging inside the bowl. You may try to hook a long hose up to the fuel tee and flip the carbs up and down and side to side while blowing in the hose to see if it close's up and stops you from breathing thru when it.s up side down. That way if it is a float that is hanging you can look at what ever side it does it on.

Hope this helps.

[DGXSER]

Well, I held the carbs in my hand, hooked up fuel flow, let it sit for about 1 full minute with fuel pressure on. No fuel out of the carbs. Moved them down as far from the tank as I could to get max pressure, no fuel flow from the carbs. Then, I disconnected the fuel line form the tank, started over to the bike to start the install, and fuel starts running out of the fuel T?? This seems odd. I went ahead and mounted them into the intakes but not gone any further.

[ccogswel]

fuel starts running out of the fuel T??

You may have a tear on that T or the rubber could be bad on that T as well for it to be leaking. Maybe even a crack. You'll want to fix that. But of corse that wouldn't be the cause of fuel coming out of the air box. You wouldn't think it would.

[John]

Did you do a float drop test? The float can drop so far as to allow the needle to cock in the seat, and not close when the bowl is full.

[DGXSER]

The fuel that ran out the T was running out of the inlet hole, where the fuel line connects. I have yet to hav efuel run from the T's other than the opening. I think I have thought it through enough to figure that one out. When I first finished my hand held fuel test, I laid the carbs down and some of the fuel ran out of the bowls through the air jets out of the carbs. This would seem expected to me. And therefore the floats had dropped opening the float valve and letting the fuel flow out the inlet. But then, the fuel level would have been above the fuel line level which seems high to me.

I will try the float drop test John. If I read it correctly this is an air test blowing into the fuel line to see if air passes with the float upside down and then slowly turning it over to see if air comes out, then again turn over to see if air is stopped when upside down.

[XSPastor]

Nope

The fuel that ran out the T was running out of the inlet hole, where the fuel line connects. I have yet to hav efuel run from the T's other than the opening. I think I have thought it through enough to figure that one out. When I first finished my hand held fuel test, I laid the carbs down and some of the fuel ran out of the bowls through the air jets out of the carbs. This would seem expected to me. And therefore the floats had dropped opening the float valve and letting the fuel flow out the inlet. But then, the fuel level would have been above the fuel line level which seems high to me.

I will try the float drop test John. If I read it correctly this is an air test blowing into the fuel line to see if air passes with the float upside down and then slowly turning it over to see if air comes out, then again turn over to see if air is stopped when upside down.

The float drop test is to hold the carbs in their mounted position with the bowls off to check if all the floats drop by the same amount. Many folks have found that the leaky carb's float drops farther than the others and wedges open. There is a tang to bend to adjust this.

[DGXSER]

Ok, completed both types of float drop test. definitely cut off air flow in the upside down position. All floats drop the same amount to my eyes anyway. remounted them. Will try fuel on the bike tomorrow.

Thanks again for all the suggestions. I will let you know what happens when I put fuel to the carbs.

[skids]

If you rebuilt the carbs with new gaskets, make sure all of the holes in the gaskets were punched-out. If no air gets in, they will flood when running but will seem OK when sitting.

Ok, completed both types of float drop test. definitely cut off air flow in the upside down position. All floats drop the same amount to my eyes anyway. remounted them. Will try fuel on the bike tomorrow.

Thanks again for all the suggestions. I will let you know what happens when I put fuel to the carbs.