SU Carby Help Needed

[sleepin22]

Looking for someone with good knowledge of SU's in Melbourne to come around and give me a hand with my setup. Its a ke20 with a 3K engine. I purchased the SU's last week and initially they were working well on the car but needed a tune. Now the car wont start and I've been trying different things during the week but to no avail. Last night the car started first go but I had set the idle too high just to get it going, so I turned it off to adjust it, then it wouldn't start again. Willing to pay someone who knows there stuff that can get it going and tuned well as I cant take it to workshop as it is. I am located in Oakleigh South. I would rather give the money to a toymodder rather than a tow truck and workshop.

[blacktop]

have you checked your timing?
this happened to my XF P/Van a long time ago.

[sleepin22]

the timing was set prior to the installation of the SU's, the car was running pretty much perfect with no pinging. I thought of that and I was going to re do the timing once the car was up and going but I cant even get it to run. It just seems to flood.

[blacktop]

checked float bowl level and little doo wacky thing that makes it go up

[Steve M]

Check to see if there is still oil in the top of the vacuum diaphragm.
If the oil drains out, the carby won't run properly.

A good place to look for SU carby information would be on Triumph and Torana GTR XU-1 sites. They have SUs.
Datsun sites might also be able to help. 240z had SUs too.

Apparentlly there are about 5 different varieties of SU, so its hard to help out.

[sleepin22]

how much oil should be in there?

[allencr]

There's nothing on a carb, and especially an SU, that won't let an engine start, unless the throttles are Completely Closed, it's flooded from dirt/stuck needle & seat, or there isn't any fuel.

The oil & damper in the piston will not affect starting, idling and most running/driving situations, only rapid throttle opening.

[oldeskewltoy]

sometimes it pays to be old... problem is I'm many thousands of miles away. I've had 3 or 4 cars with SUs... mostly HS6s.

The symptoms you describe doesn't sound like a carb problem... SUs are rather simple... fuel bowl... metered pipe..... and a machined tapered needle... there isn't much more to an SU. As you can see there aren't that many parts...




Here are a few links to check further....
http://sw-em.com/su_carbs.htm
http://roversd1.info/2600/carburetor.html
http://members.core.com/~ckotting/tuning.html

[sleepin22]

There's nothing on a carb, and especially an SU, that won't let an engine start, unless the throttles are Completely Closed, it's flooded from dirt/stuck needle & seat, or there isn't any fuel.

The oil & damper in the piston will not affect starting, idling and most running/driving situations, only rapid throttle opening.

Kool, well I can rule out a carby problem as I dont have any of the issues that you have mentioned. I will recheck the timing today. Its the only thing I can think of that could be causing this. I have also been told that these cars have issues with the ballast resistor but mine does not have one. So this could not be the problem, but i will install one in the future.

[sleepin22]

ok, well I managed to get it running a few times today for about 10-15 minutes each time. Looks like the problem is with the SU's as it keeps fouling the plugs each time and wont reatart after I turn it off. No matter how lean I go on the adjustments it still spews out blackish smoke and fouls the plugs. So from my limited knowledge I'm guessing that the needles may be too big for my application and I possibly need to get smaller ones fitted. As I Have no idea what these SU's came off I think this would be the most logical explanation. Can someone verify my train of thought?

[madmont]

Smaller needles will give you a richer mixture due to the greater space for the fuel to go through. Screwing the jet up towards the needle will give you a leaner mixture. Check your needle and seat and float level.

[sleepin22]

yeah, I worded it wrong. I meant that they might be too small. How do u check the float level on these?

[madmont]

The below link looks like it will provide info for setting level
http://www.gowerlee.dircon.co.uk/Tips.htm

[sleepin22]

problem solved. Floats are shagged. This would make it run rich right?/

[blacktop]

ha that mean i was right from the beginning (second post), this has never happened to me before.