Problems fueling my su carb! need help!

[bombz4]

This is quite hard because my car is at home and im at uni. My farther and his mate (both mechanics) have been unable to get it working. The carb was recently stripped and looked fine, but it is now on the car but seems to be unable to give enough fuel (the carb setting have been unalterd since i bought the carb). The car did start briefly for around 20 seconds but since barley fires up. All the seals have been checked etc. My dad is now wondering wether its because the carb is at an angle (10.30ish in clock angles! would this be enough to effect the float?). I dont really know what the next step is! I cant really afford to get it to a garage or put it into one. Im almost debating putting the webber back on! can anyone give me any advice that i can relay to my dad?
Also my oil light is staying on, even with the ignition off. can anyone shed light on this?
This car has been one problem after another! i was intending to get it running and take it to a RR to get the fueling perfected. but while its a non-runner i cant do anything, im extremely busy with uni and my dad works so getting time to work on it is never easy! any ideas? cheers bomb

 

[whipit]

Got any pictures of your setup? Do put the weber back on to make sure the engine is working all ok rather than blame the su.

 

[alchemyst]

if its a mini type su then two things i would check are that no bits of crud are blocking the main jet (unscrew it and look!) and check that the float is not jammed (again take the needle valve out and check its all clean).
you would be amazed at how small a piece of cr*p it takes to block both of these!, plus make sure you have an inline filter between the pump and carb to keep the fuel clean will save you loads of future hassles (Y)
su carbs are designed to fit at an angle and are at about10-11 oclock on most (not all!) cars they are fitted to.
what sort of su is it and what did it come off?

 

[bobsp16]

you will need to thin the needle down a bit its running to lean..
i do this by spinning the needle in a drill and use fine sand paper...
start working the needle about 15mm down from the point were it fits into the piston...only take off a little at a time

 

[SammoHung]

I'm new to SU's but am enthusiastic about these...

Im not sure about how sensetive the angle of the float chamber is...but for my project so far Im assuming it is critical..

is yourfuel chamber separate of do you have a flashy HIF style one?

..I have examined my HS fuel bowl and it seems that the angle of teh fuel bowl could be altered so that it is vertical...and still have the carb as an angle...(this may require an extra sealing washer between the bowl and the carb to act as a spacer so that the bowl can be rotated

I havent investigated this idea thoroughly though so I cant be certain.

another thought is..perhaps the angle is so steep that the piston is sticking ddue to friction preventing it from rising up easily as the rpm increases...

can you get your finger in and check that is moves freely up and down at this angle?

This will be most likely if the piston is the "non-ball-bearing type"

dont give up on the SU....

'hope this hlps in some way or other

 

[bobsp16]

if you are using the older hs 1.3/4 inch su with the seperate fuel bowl you can adjust it so its level...and yes you should be able to move the piston up from the air filter side.
they say that you shouldn,t lean an su past 40deg

 

[bombz4]

its up and running! it had something lodged behind the float. Its not running 100% but it idles ok (slightly lumpy) just needs the choke cable attatching and a few other things. Hope fully getting some guy to krypton tune it in the week! (think thats the machine they have!)

 

[SammoHung]

how much is the tuning if you dont mind me asking.....? (I guess thay have experience with constant vacuum carbs there?)

 

[alchemyst]

its up and running! it had something lodged behind the float. Its not running 100% but it idles ok (slightly lumpy) just needs the choke cable attatching and a few other things. Hope fully getting some guy to krypton tune it in the week! (think thats the machine they have!)

i would sugest you actually take it to someone who does mini's as they will have experience of setting up the su carb plus you will probably need a different needle in it to get fueling correct and your local krypton tune bloke is very unlikely to have these!
su carbs are a brilliant and simple bit of kit and very easy to set up by the home mechanic but to get it spot on you really need someone with the knowledge to do it properly, check out mini mag or miniworld for people local to you.

 

[bombz4]

i would sugest you actually take it to someone who does mini's as they will have experience of setting up the su carb plus you will probably need a different needle in it to get fueling correct and your local krypton tune bloke is very unlikely to have these!
su carbs are a brilliant and simple bit of kit and very easy to set up by the home mechanic but to get it spot on you really need someone with the knowledge to do it properly, check out mini mag or miniworld for people local to you.

good idea! i love minis and would enjoy the read too. well my original thoughts were to get it set up on a rolling road but I would like to get an exhaust manifold first, Basically its a krypton tuner on the raf camp, and some guy with previous experience of SU carbs. I realise that this isn't perfect but atleast i will have a driveable car again.

My dad is also slowly learning more about tuning these things. He usually hates my car because the engine isn't fully standard, but when he phoned once he had it running, he sounded like an excited kid!

I'd also like to research super charging su carbs (although im sure its more of a dream, than target next mod) and firstly need it running A1 before messing around with anything else!

 

[alchemyst]

good idea! i love minis and would enjoy the read too. well my original thoughts were to get it set up on a rolling road but I would like to get an exhaust manifold first, Basically its a krypton tuner on the raf camp, and some guy with previous experience of SU carbs. I realise that this isn't perfect but atleast i will have a driveable car again.

My dad is also slowly learning more about tuning these things. He usually hates my car because the engine isn't fully standard, but when he phoned once he had it running, he sounded like an excited kid!

I'd also like to research super charging su carbs (although im sure its more of a dream, than target next mod) and firstly need it running A1 before messing around with anything else!

minis are running around with the superharger off the bmw coopers on them you can even buy kits for the a series (mini) engine, most have the su before the supercharger in a suck through method but you could use a turbo hiff44 and put it after the supercharger run pressurised! (make sure it is a turbo one though or it will pee fuel out under pressure!)

 

[bombz4]

cheers alchemist, sounds like you know your stuff, as I said at the moment I dont have the funding or the knowledge for this project. Also i dont really think there are too many years left on my car! Once this carb works nicely i'd like to find another way to keep modding the engine, I need to find a way to get an exhaust manifold before my student loan runs out!