All previous advice is recommended, fuel pressure (if you are using an old LP electric fuel pump you should not need a pressure regulator), float level (23mm from the top of the bowl), needle and seats are working etc.
Another thing to check is the mixture setting, as your description suggest its running rich. I dont know of fuel returns to the tank on SU's but I do know that some had overflow pipes which simply allowed any excess to drain to ground, via metal pipes which dropped excess fuel down past the exhaust system. Assuming all the other things are fixed, and it still blows black smoke (runs rich), adjust the screw under the base of each carb up, until the base of the jet that the needle sticks into is flush with the base of the venturi. Then rotate the adjusting screw 2 turns back, to lower the base to the correct setting. This gives a basic starting point for mixture accuracy. ----- Original Message ----- From: "Bob" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, 30 August 2002 18:34 PM Subject: Re: Fuel Leak? Help.. > I spent a fair time today trying to get them going properly, to no > avail, it still starts badly, runs badly, all accompanied with black > smoke. Given that it is unregulated at the moment, I think it is a > fair guess that it could be the problem. I also have the heatshield > off my old carbs that looks like it will pretty well bolt on, so I > guess its going to get a polish up. As for the fuel pump switch, I > have another project on the go with regards to that.. > > Friday, August 30, 2002, 4:34:52 PM, you wrote: > > aoca> Classic :) > aoca> Deja-Vu or what > > aoca> Return line hahaha. > aoca> I spent ages putting a return line in my car and there just isn't enough power to pump it back into the tank :) > > aoca> Check the carbs first, > aoca> Set the float level, centre the needle, etc..etc.. try to tune them as best you can. > > aoca> I tried an adjustable recgulator from a 105 series Alfa mmm looks good, but doesn't work :( > > aoca> I bought an adjustable in-line US made regulator (profuelator?) for about $30.00 or something. > > aoca> It was a revelation, before the car used sooo much fuel, didn't idle, stalled at the bottom of hills etc.. etc.. > > aoca> Also if they are British.. then you should make a 'heatshield' for under the carbs. > aoca> The actual key function of this heatshield is to stop fuel dripping onto the (hot) exhaust manifold, although it does give more power as well. > > aoca> Another mod is to have a dash switch to control the electric pump. Turn the pump off about 30 seconds before you reach your destination. > aoca> It functions as an anti theft device and when you go to start up again you turn the pump on and get nice fresh fuel in the bowls for easy starting. > > > aoca> Good luck > aoca> Those carbs will keep you busy hehe > > aoca> Regards, > aoca> Nick > >> > >> From: Bob <[EMAIL PROTECTED]> > >> Subject: Re: Fuel Leak? Help.. > >> Date: 30/08/2002 16:01:07 > >> To: [EMAIL PROTECTED] > >> > >> They are the british SUs. I have an electric pump, and at the end of > >> the steel tube that runs to the tank there is a big restrictor, I am > >> guessing that is a crude pressure regulator, perhaps that is holding > >> the pressure too high and causing me problems.. I might try putting > >> some kind of pressure regulator before the carbies to knock the > >> pressure down. Does anyone have any recommendations on a regulator I > >> can get? > >> > >> Friday, August 30, 2002, 2:42:04 PM, you wrote: > >> > >> aoca> The classic link to try is > >> aoca> http://home.istar.ca/~datsun/att06.htm > >> > >> aoca> Sounds like either float level or fuel pressure. > >> > >> aoca> What type of SU's are they > >> aoca> -Genuine British Skinner-Union jobbies > >> aoca> -Hitachi's > >> > >> aoca> You have to modify the Genuine SU's a bit to make them work (love that British Engineering) they can only handle 1.5PSI fuel pressure and the float bowls need to be rotated a bit to make them > >> aoca> sit vertically. > >> > >> aoca> Regards, > >> aoca> Nick > >> >> > >> >> From: Bob <[EMAIL PROTECTED]> > >> >> Subject: Fuel Leak? Help.. > >> >> Date: 30/08/2002 14:17:21 > >> >> To: [EMAIL PROTECTED] > >> >> > >> >> Hello membersozdat, > >> >> > >> >> Ive just been trying to tune these new SUs in, and when I cut the > >> >> engine fuel slowly leaks out of the jets, out the mouth of the > >> >> carby, and drips down right next to my exhaust... can anybody tell > >> >> me what could be going on here? Im no expert, but that cant be > >> >> normal. I am thinking incorrect float levels could be it? Or maybe I > >> >> have the fuel hoses on the wrong way arround, I have the line from > >> >> the pump going into the higher fitting, and the return line going > >> >> into the lower fitting. The return lines then go into a T which goes > >> >> back to the tank. Any help would be much appreciated, I dont want to > >> >> see my car burn to the ground... > >> >> > >> >> -- > >> >> Best regards, > >> >> Bob mailto:[EMAIL PROTECTED] > >> >> > >> >> > >> > >> aoca> This message was sent through MyMail http://www.mymail.com.au > >> > >> > >> > >> > >> > >> -- > >> Best regards, > >> Bob mailto:[EMAIL PROTECTED] > >> > >> > > aoca> This message was sent through MyMail http://www.mymail.com.au > > > > > > -- > Best regards, > Bob mailto:[EMAIL PROTECTED] > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
