Leaking SU carbs

[seerex]

My 72 240 had su carbs , on the top of the carbs there are two hoses coming out one is from the fuel rail and the other goes to the factory aircleaner . When I try and start the car fuel pours from the rear carb where the hose goes into the aircleaner ,I have tried to insert a pic . not sure if it worked. These are the only to fuel style lines from the top of the carbs . And only the one closest to the fire wall is doing this . As a bit of info the car hasn't been ran in about two years , I just replaced all of the ingition and starter < thanks to all who helped with that issue> and does have the smog pump hooked up <which I want to remove with all that crap > Please any helps thanks Jeff

[ZmeFly]

the vent (overflow) hose from the floats. check and readjust your float levels. make sure the system is working properly and its stopping the flow of fuel when your float reaches its stop point.

[seerex]

Am i postponing a rebuild here? should i just take them off and rebuild them fully or is this pretty common ? The car has sat for like 2 years , got the car to turn over but won't fire yet

[Victor Laury]

Quick test. Swap bowl covers.

AND Open the bowls and see which style floats you have. If tyou have the loose, brass float, you may have a sunk one, where gas has seeped into the float enough to overflow the bowl.

This isn't a biggie, don't tear the carbs apart....yet. Fix this issue and then see if everything is OK?

hope this makes sense. been hittin the tequila tonight.

[seerex]

Thanks I have been hiting the rum so it wil make sense tonight but maybe not tomarrow morning thanks

[seerex]

when checking the floats just unscrew the four top screws and thats it ? should i remove the gas line first and if the float is stuck i assume its at the bottom?

[Victor Laury]

I just saw your photo. 1972 3 screw carbs have the attached plastic float that is NOT prone to sinking. I'll bet you just need to clean the bowl jets.

No biggie-undo the fuel line, and remove the four screws on the bowl cover. When you lift the bowl cover off, the float should be attached. remove the float hinge pin and place pin and float aside. You will see the bowl jet in the cover. Remove it and clean it. What you may find is a piece of teflon thread sealing tape caught in the jet.

[seerex]

Ok i checked the piston for lack of a better term in the carbs and raised them and they lowered by themselves but when you use the accelerator using petal or manually on the manifold the carbs stick and do not return , big issue or not with reguard to the carbs

[Chino 240Z]

I agree with these checks.

Gently remove cover and slowly lift out float.

Check for gas in the float, is the float swollen?

Should have fairly nice edge not fully rounded or ballooned up.

After removing gas jet valve and carefully take apart and check for debris. Put back together and install float back onto cover.

With cover upside down and level the float should be gently settled about 9/16" space between float and bottom of cover. Adjust by tweaking little lever that pushes the gas valve closed.

Check for junk in bottom of bowl before you reassemble the cover.

I think you should solve the gas overflowing problem before you go to the next step and that will be getting into the carb to check and set the main jet needle and nozzel, and to check, clean, and to quick test the piston to be sure it is operating ok and not hanging up.

If you tear into the carbs only do one at a time incase you can't remember which part or screw went where.

Good Luck

[Chino 240Z]

So you got the car running? and you say the pistons don't down back down after you let off the throttle? If you use your finger and the raise and drop and go clunk then they should be okay. Besure that your butterfly valve is closing after you release the throttle. You only want them open a crack for the car the idle. If they are more the idle maybe so great that the vaccum is holding the piston up. Is the engine run fast? or just idling? You can pull off top of piston dome and remove piston, spring, and dome to clean with carb cleaner. Becareful when inserting piston back so you align the needle back into the nozzle hole gently. You don't want to bend it, or a bent needle that rubs the edge of the nozzle will keep the piston from dropping back down. You might want to check this too!

[seerex]

the car is not running presently I am getting no fire yet i just checked the ignition and i sprayed starting fluid up in the carbs and all it did was run out , it sounded like a car that was out of fuel , it has sat for 2 years and not run and the fuel running out of the carbs was a sign to check them first

[Chino 240Z]

I'm not sure the gas is still good after sitting for 2 years in the tank? But if it ran on starting fluid it is a good sign that it will turn over. Besure to dump all the fluids and start fresh. Clean your plugs and anything else just so it will help it fire up when you go a cranking on it, hopefully it won't grind for to long. I do know, but if you have had fuel pouring out of carbs, the cylinders are probably to gas wet to fire. Also a fresh or full charged battery so you have full voltage for spark and the abuility for the starter to crank without dragging.