lumpy carb

[ohc_turbo]

firstly what ive done is put a 1.0 carb, manifold and everything onto a 1.2 block.

the car is running lumpy with flat spots and everything, firstly its a bit of a pig on cold startup but not that bad and then it idle's at 1500 untill lets say 20min of driving and it bogs down to 400-500 and stalls on deacelleration(comming up to traffic lights etc)


all the time its lumpy and when i rev it it gradually goes down and sometimes if i rev it to lets sat 3000 and let off it will climb up a bit more before it falls down - weird?


i can hear a hissing sound when im sitting in the cockpit, checked around the carb and everything seems connected, the crankcase ventilation pipe is a bit loose but this wouldnt do this, thinking of blocking that off anyway.

as far as im aware i transfered the carb without disconnecting anything, maybe the 1.0 carb isnt sutable for the 1.2?

help

 

[ohc_turbo]

should i much about with the mixture screw and the timing or should i leave that alone?

 

[micra man]

Mine did this also, think you may have to either clean or replace the carb. Should solve the problem.

 

[Speedle]

a good way to set the carb up to a resonable running level is to fully screw inthe mixture screw and then unscrew it 1 and a half to 2 turns this will set the mixture to somewhere near what it needs to be but id recomend using a gas analyser to get it proper sorted i can usually tune carbs by ear and feel its trial and error really but suprisingly simple after some practice

 

[AMY]

has anyone actually fitted a 1.0 carb to 1.2 before? I know there was some speculation that it would work but I'm not convinced it will deliver enough fuel.

 

[Speedle]

the 1.0 carb apprently has a larger jet than the 1.2, i spoke with ed on length about this once tbh i think the power gain iof any would be very neglagable

 

[ohc_turbo]

think i sorted this out, a vacuum pipe was off, put it back on and its much better, its still lumpy a bit though

 

[AMY]

Speedle,
I seem to remember reading that there was an electronicaly controlled valve to supply additional fuel?