Newbie with Carburetor questions

[kevenj]

I'm brand new here and while I have basic automotive knowledge, I'm not real familiar with these cars, so I'm looking for some short cuts:)

I have a 1973 240Z in my back yard that belongs to a young friend of mine who bit off more than he can chew; I have no idea when it last ran but it's been in my yard for 2 years now. It is a complete "project car" and he's in no position to restore it so now it is for sale. I want to see if I can at least get it to run to make it a little more attractive to a potential buyer. I transferred a battery from another car and the starter spins the engine over. I've got compression, I've got spark, but the fuel line from the tank seems to be completely blocked; I cant even blow through it with my air compressor at 150 psi. So I temporarily ran a hose from the inlet side of the fuel pump into a gas can and after cranking the engine over for a couple minutes I got fuel to the carburetors, so the fuel pump is working. At this point I was thinking I'd have it running soon...maybe not well, but at least running. But as I contuined to crank it over, raw fuel started pouring out of both carburetors (had the air cleaner off). I had to stop tinkering 'cuz I had someplace to be, but I guess I need to tear into the carbs and at least give them a good cleaning. My question is, what in particular with the SU carbs should I look for that would cause this. I've never worked on side draft carbs before so I'm not sure what I'm getting into, and since this car is not even mine I don't really want to spend any more $$ on it than is absolutely necessary to get her to run and then find her a good home.

Any help is appreciated.

[MikeW]

Welcome. Can you determine if the car has the original "flat top" carbs that came on the 73s or have they been replaced with earlier "round top" carbs? Where specifically is the fuel leaking from? Pictures would help; you can post them as attachments.

[Arne]

Sounds like sticky floats. If the car has the earlier '70-72 carbs on it (and many '73s do), the float bowls are separate and mounted on the sides of the carbs.

If it still has the original '73 carbs, I'm not familiar with those so I don't know where the float bowls on them are located.

[kevenj]

Welcome. Can you determine if the car has the original "flat top" carbs that came on the 73s or have they been replaced with earlier "round top" carbs? Where specifically is the fuel leaking from? Pictures would help; you can post them as attachments.

The tops are flat and there is a rod that kinda looks like a dipstick that screws into each one.

The fuel is pouring out of the throats of each carburetor - - what would be the top of a downdraft carburetor like I'm used to. I cannot take any pictures right now, the car is outside and not much light. I may tinker with it some more tomorrow.

[Arne]

OK, if the carb throats are round, you have early round-top carbs with separate floats. If you have square carb throats, you have flat-top carbs, where the float bowls are built into the bottom of the carbs. Either way, you'll need to get to the floats and clean them up.

[1 Bravo 6]

G'Day Kevin,

Mate, ... complete your public profile. You never know, there just might be another member living close by who could help out. For that matter, a member might be a potential buyer.

It would be a BIG help if you could post some pix, not only of the carbies but of the car itself, to show the general condition.

Rick.

:devious: :devious:

[kevenj]

Thanks all; I have the flat top carbs then. I may not get to tear into her again until next weekend but I will post pics of the car later today in case anyone is interested in giving her a new home; I'm in Coeur d' alene, Idaho in the great Northwest!

[kevenj]

OK, if the carb throats are round, you have early round-top carbs with separate floats. If you have square carb throats, you have flat-top carbs, where the float bowls are built into the bottom of the carbs. Either way, you'll need to get to the floats and clean them up.

Here is a picture of the carbs I have, they are both pouring raw fuel out of the throats where I'm pointing in the picture. Can I just remove that top part of the carburetor (the part that looks like a soup can) and clean everything out or do i have to completely disassemble the carbs to unstick the floats? Thanks!

P.S. I'm posting some pics of the car in the classified section.

[Zedrally]

The carbs you have are flat tops and have an integral float.

The bad news is that you will need to dis-assemble just to adjust the float level.

Before you do this, it would be wise to find an overhaul kit.

Serch for flat top carbs, there a a few of us that still use them....

[Arne]

Mike is right, the floats in those are in the bottom of the carb. Removing the dome won't give you access.

[deadflo]

Kevin, Sorry I cant be of more help, I am just across the border in the Spokane area. I do know how to set the floats in the dome top carbs, but not the flat tops. Maybe do a search here for flat top floats or something similar? I think the Haynes or Chiltons manual has the proceeedure.

[Zedrally]

This is another possibility which is that the idle mixture is set to rich.

This is the one mixture adjustment that can be done to these carbs without ripping the whole lot apart.

From memory it's the large 1/2" spring loaded bolt.

You may be just running rich, FWIW and worth looking at.

Do you have a FSM, that will explain the procedure required to tune-up.

MOM