ausmini :: View topic - Please Help me with Twin SU's

one of my carbies has two pipes on top of the fuel bowl. so i have attached the fuel in to one, then connected the other carbie to the other pipe. has anyone seen this before?

This is wrong mate, the carb float bowls are joined by a connecting pipe or a Y piece & hose. The carb with the twin outlet on the float bowl has a inlet pipe and a breather pipe. You have connected the 2nd carb to the breather pipe & no fuel is getting to the 2nd carb. Join the 2 via a connecting pipe & leave the breather open (or better remove the breather lid & fit the correct type) and hopefully this will fix your problem.

would i need to change my timing because i have changed the carbies over?

Author:	Stuart2004 [ Sat Jul 18, 2009 6:36 pm ]
Post subject:	Please Help me with Twin SU's
Hi All, I was wondering if someone could give me some pointers. I have just recently attempted to put twin SU's on my 1310. However i can not get the thing to start. It will kick over when i spray some "start ya bastard" in however will not continue to run. I have the carbies at 11 - 12 flats in relation to the mixture screw. nothing i do helps. any pointers? THanks

Author:	i got a mini [ Sat Jul 18, 2009 7:03 pm ]
Post subject:
is the fuel pump pumping fuel

Author:	4myego [ Sat Jul 18, 2009 7:13 pm ]
Post subject:
Good point, The first thing to do is remove the fuel hose leading to the carbie junction pipe and make sure fuel is being pumped. Check the piston inside the carbie is rising and falling freely with your fingers All throttle linkages OK, butterflies opening Maybe post a photo of the linkage setup Just a foot note: Make sure also dash pot is filled with oil ( I use auto transmission oil - nice and light, just right)

Author:	sitnlo62 [ Sat Jul 18, 2009 8:08 pm ]
Post subject:
Stuart, Check that you have a good seal between the manifold and head. No doubt you have changed the intake manifold? Check that the manifold is hard up against the gasket and not being held back by the extractor flanges on either side. I have fitted a couple of sets of Maniflow extractors recently and have had to grind the top corner off the flange because it was fouling the factory twin manifold not allowing it to butt up hard against the gasket. I have assumed you have already checked fuel delivery to the float bowls and free flow of fuel through the jet to the point of delivery? Dave

Author:	i got a mini [ Sat Jul 18, 2009 8:14 pm ]
Post subject:
yer my bro had a prob with the piston wasnt centred and it kept jamming check that and check fuel bowl has fuel in it

ausmini https://www.ausmini.com/forums/

Please Help me with Twin SU's https://www.ausmini.com/forums/viewtopic.php?f=2&t=55242	Page 1 of 1

Author:	Stuart2004 [ Wed Jul 22, 2009 10:39 pm ]
Post subject:
Thanks for all your pointers, This is what i have come up with so far. Manifold - The inlet manifold is thicker at the flange than the exhaust, so i think it should be making a good seal, i have taken it off and there does not seem to be any leaking from through the manifold. Fuel - the pump is pumping, i am sure that there is fuel in the fuel bowl. Pistons - There is oil in there, they move with some pressure, should they be really easy or should i have to push just a little to get them moving? one of my carbies has two pipes on top of the fuel bowl. so i have attached the fuel in to one, then connected the other carbie to the other pipe. has anyone seen this before? i will see if i can post some pictures on the weekend. would i need to change my timing because i have changed the carbies over?

Author:	sgc [ Wed Jul 22, 2009 10:51 pm ]
Post subject:
Stuart2004 wrote: one of my carbies has two pipes on top of the fuel bowl. so i have attached the fuel in to one, then connected the other carbie to the other pipe. has anyone seen this before? Usually the float bowl lids with two pipes have one being the inlet and the other a vent which is usually plumbed to the charcoal canister found on clubbies. Do you have fuel in the second float bowl? Stuart2004 wrote: would i need to change my timing because i have changed the carbies over? Nope.

Author:	850man [ Wed Jul 22, 2009 11:02 pm ]
Post subject:
Stuart2004 wrote: one of my carbies has two pipes on top of the fuel bowl. so i have attached the fuel in to one, then connected the other carbie to the other pipe. has anyone seen this before? This is wrong mate, the carb float bowls are joined by a connecting pipe or a Y piece & hose. The carb with the twin outlet on the float bowl has a inlet pipe and a breather pipe. You have connected the 2nd carb to the breather pipe & no fuel is getting to the 2nd carb. Join the 2 via a connecting pipe & leave the breather open (or better remove the breather lid & fit the correct type) and hopefully this will fix your problem. would i need to change my timing because i have changed the carbies over? Timing should be ok, as long as it was ok to start with.

Page 1 of 1	All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/