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su carb running help

Posted: Sun Feb 19, 2012 6:21 pm
by jgp1986
ive fitted an hif44 to my samurai ive followed the guides on here and its all fitted right, im using a manifold adaptor with water jacket.
ive got it started up and its runs very lumpy then makes a pop out of the air filter side and cuts out
could someone please help me and push me in the right direction of setting it up,

cheers jonno

Re: su carb running help

Posted: Sun Feb 19, 2012 7:08 pm
by twiss
Firstly you want to make sure its all connected right.
As its running that means the fuel hoses are all OK :)

Have you blocked off the breather on the carb?
Its the breather towards the top right of the carb, looking from in front of the car.

Is the vacuum advance connected correctly?
If you have the correct type of vac advance,is it connected to the distributor?

Does the carb have the correct type of vac advance?
If the vac advance takeoff point is on the wrong side of the carb butterfly if will be advancing at the wrong time.

What needle and spring do you have?
As its a 1.3 Samurai, you will need either a BDL or BCZ needle with a red spring

What oil is in the carb dashpot?
You should have SU damper oil, or some people use 3-in-1.

Is the mixture set correctly?
It sounds like the mixture is off for sure. turn the mixture screw in all the way, then back out 3.5 turns
This is a good starting point. Adjust the idle screw to get the engine started.
When the engine is warmed up, gradually adjust the mixture screw until you hear the engine speed picking up. You will hear it through the exhaust tone as well.
Once the engine is running at its fastest, turn the idle speed to get to 800rpm-ish.
Then adjust the mixture to get the highest engine speed, then adjust the idle to 800 again.

Re: su carb running help

Posted: Sun Feb 19, 2012 7:16 pm
by jgp1986
all is connected correctly and blanked off as shown on here in the guide.

ive checked the spring and it is a red and also sure the needles correct

The only one im not completely sure of is the vac advance which side of the butterfly should it be, mine goes behind the butterfly as in you cant see where it comes out when the butterfly is closed,

Re: su carb running help

Posted: Sun Feb 19, 2012 9:20 pm
by twiss
so you mean if the carb is off and you cant see the hole with the butterfly closed that is correct!
If you take the vac hose off the dizzy, it should suck a little tiny bit through the pipe on idle, and suck a lot on throttle.

I'm pretty sure that back-fire in the inlet manifold means it's too lean rather than too rich.
What air filter arrangement do you have? Is it possible you have disturbed the inlet manifold gasket?
Also what gaskets did you use between the manfold/adapter/carb?

Re: su carb running help

Posted: Sun Feb 19, 2012 9:29 pm
by jgp1986
yes thats correct,

ive no filter on it at the moment,
no ive not touched the inlet apart from opening it up into one port
ive made my own using gasket paper and used a small amount of gasket sealant,

thanks for helping

Re: su carb running help

Posted: Sun Feb 19, 2012 9:41 pm
by twiss
hmmm in that case it might be cos u dont have a filter of any kind on there.
I found that when I had a massive air filter on my 1.3 with SU it wouldn't run properly cos I couldnt adjust the mixture any further.

You could try partially blocking the air intake with something to simulate a bit of resistance and see if that helps? Like cover 50% of it...

Re: su carb running help

Posted: Sun Feb 19, 2012 9:44 pm
by jgp1986
aaahhh right ok ill give that a try after work tomorrow
hopefully ill get it sorted ill have a tinker and post the outcome

cheers
jonno

Re: su carb running help

Posted: Sun Feb 19, 2012 11:44 pm
by ScottieJ
Is the timing all correct, I.e. did you have the leads off or has dizzy come out at any point between it last running and you fitting the SU? I know you don't touch them during the carb swap but I mean for anything else you might've been working on?

Re: su carb running help

Posted: Mon Feb 20, 2012 2:32 pm
by jgp1986
I had took the leads and that off but put all that back together and had it running fine before swapping the carb
i originally thought it could of been them making the standard carb splutter
but replaced with new ones

Re: su carb running help

Posted: Mon Feb 20, 2012 5:36 pm
by jgp1986
been and had a play its running now starts pretty easy but still has a little miss fire and makes a pinking noise?