Hi again, my garage had a tweak of my new empi carb to try to improve the running , it is starting really well when cold but needs winding over and the throttle pumping when hot or warm, they put it on the emissions tester and when they revved it it was going really weak. When I put my throttle pedal down hard, it bogs down until I ease off my foot then it picks up , Justin at retro dubs thinks the carbs come with another jet I haven't had time to check the box yet but does this sound like it could be my problem, seems to make a bit of sense that a bigger hey would give more fuel when I boot it.  Any experience of similar with the empi carb ? Many thanks .

Quote from: mad4slalom on November 11, 2016, 06:55:26 PM
Hi again, my garage had a tweak of my new empi carb to try to improve the running , it is starting really well when cold but needs winding over and the throttle pumping when hot or warm, they put it on the emissions tester and when they revved it it was going really weak. When I put my throttle pedal down hard, it bogs down until I ease off my foot then it picks up , Justin at retro dubs thinks the carbs come with another jet I haven't had time to check the box yet but does this sound like it could be my problem, seems to make a bit of sense that a bigger hey would give more fuel when I boot it.  Any experience of similar with the empi carb ? Many thanks .

oops typo, that was JET not hey !!

Check the jet sizes on a standard solex carb for your engine they will be in a manual or online as a guide against what your empi copy has fitted.

Quote from: snoopy on November 11, 2016, 07:12:22 PM
Check the jet sizes on a standard solex carb for your engine they will be in a manual or online as a guide against what your empi copy has fitted.

.  Ok thanks for that, I will see what's in there,

Quote from: mad4slalom on November 11, 2016, 11:22:55 PM

Quote from: snoopy on November 11, 2016, 07:12:22 PM
Check the jet sizes on a standard solex carb for your engine they will be in a manual or online as a guide against what your empi copy has fitted.

.  Ok thanks for that, I will see what's in there,

. Looked online and a lot of folk say you need to jet up the empi  to130 main and a smaller 50 instead of 80 air bypass jet, these came with the carb so will try this tonight

Well , last night I swapped out the jets in the empi carb, read that it should need a 130 main and a 50 idle jet , took out the idle which was already a 50. Bit of trouble with the main, I tried to do it in situ, removed bolt , drained the carb bowl and unscrewed main jet,it was now loose in the bottom of the carb so was teasing it out through the bolt hole when it suddenly flicked out and disappeared!, can't find the jet anywhere, now I didn't see or hear where it landed which made me wonder if it had flipped into the carb somewhere, I had a poke around with a bit of bent fuse wire and couldn't locate it so I am hoping it just dropped in amongst the engine barrel or tinware. Fitted a new 130!main jet and replaced drain plug bolt, only thing is I don't know what size the old one was and also have a niggle that it could be in the bowl somewhere. It idled ok before so hopefully the 50 was right and hoping the 130 main is bigger than what was in there before as is bogging down and is weak on an emissions machine when throttle blipped, too wet in Cornwall to road test yet. Anyone had one of these empi 34 pict carbs and knows what main jet size it came with, and did you jet it up ?  Many thanks.

Not sure about empi, which carb is it ?

The Brosal H30/31 from Heritage is supplied with 2 jets, a 130 and a 120...

From the Heritage site...
A ''universal'' carburettor.
Brosol 30/31 PICT 1 single arm carburettor with cut off valve. Comes supplied with 130 Main jet fitted for use with 1600cc engines. A 120 main jet is supplied loose in the box for smaller engines 1200-1500cc. An adapter plate is included for the fitment to 1600cc manifolds this is not used on 1200-1500cc engines.

Quote from: Pondlife on November 18, 2016, 01:25:43 PM
Not sure about empi, which carb is it ?

The Brosal H30/31 from Heritage is supplied with 2 jets, a 130 and a 120...

From the Heritage site...
A ''universal'' carburettor.
Brosol 30/31 PICT 1 single arm carburettor with cut off valve. Comes supplied with 130 Main jet fitted for use with 1600cc engines. A 120 main jet is supplied loose in the box for smaller engines 1200-1500cc. An adapter plate is included for the fitment to 1600cc manifolds this is not used on 1200-1500cc engines.  Thanks pond life, the carb came with jets fitted but don't know which main jet was in there and now it's lost!! Also in the box were the 130 main ( that I fitted ) and a 127 main and an 80 idle, so , the idle is definitely a 50 and the main is definitely a 130, the only thing I don't know is what size the main jet that dissapeared was .

Quote from: mad4slalom on November 18, 2016, 11:46:15 AM
Well , last night I swapped out the jets in the empi carb, read that it should need a 130 main and a 50 idle jet , took out the idle which was already a 50. Bit of trouble with the main, I tried to do it in situ, removed bolt , drained the carb bowl and unscrewed main jet,it was now loose in the bottom of the carb so was teasing it out through the bolt hole when it suddenly flicked out and disappeared!, can't find the jet anywhere, now I didn't see or hear where it landed which made me wonder if it had flipped into the carb somewhere, I had a poke around with a bit of bent fuse wire and couldn't locate it so I am hoping it just dropped in amongst the engine barrel or tinware. Fitted a new 130!main jet and replaced drain plug bolt, only thing is I don't know what size the old one was and also have a niggle that it could be in the bowl somewhere. It idled ok before so hopefully the 50 was right and hoping the 130 main is bigger than what was in there before as is bogging down and is weak on an emissions machine when throttle blipped, too wet in Cornwall to road test yet. Anyone had one of these empi 34 pict carbs and knows what main jet size it came with, and did you jet it up ?  Many thanks.

.  Well , road tested bug today and since I changed to a 130 main jet it is better in that it doesn't bog down now , it started better from hot the first time I tried it then stopped for fuel and after chatting for a while had to really wind it over for a long time to get it to fire then had to rev it to clear its throat then drove ok again, still carburation or ignition timing needs a tweek on the distributor ?, any suggestions  , thanks 

Could be fuel vapourisation in the carb when the engine is hot.

Sounds like the electric choke wants backing off some more!

Rob

Quote from: farmer rob on November 24, 2016, 06:29:08 PM
Sounds like the electric choke wants backing off some more!

Rob

thanks , it starts instantly again if I turn it off and start it again right away, but if left for ten or fifteen minutes it needs winding over and throttle pumping gas to get it to start then a good reve to clear it. Tried holding down the throttle when hot starting which some say is the correct procedure and is better but still not good, maybe just need to experiment to find what needs doing to start when hot. It has cannons which someone said cause uneven running sometimes, I tested again on the road and still getting some bogging down tho not as bad as it was, it did stall once at a junction too, but generally ticks over ok , any suggestions gratefully received 

Just an idea but have you checked for air leaks on the inlet manifold ends or the carb spindles ??

When you say bogging down, going lumpy and chugging with black smoke or will not pick up and needs the accelerator used.

Annoying faults like this as there is no real fault to repair and say it is done, more just trial and error.
May be a weAk idle mixture that evaporates due to the heat build up when the engine is turned off and left before it cools after standing a while.

Is your fuel pump supplying enough pressure?