4 replies to this topic

[JamesleppAFC]

Hi I have a 1993 rover mini sprite I've done the timing and need it to run a bit better, it has a su hif 44 carb, at the moment there's a popping sound coming from the engine and the spark plugs are black and fairly new to this so can anyone explain clearly what I need to do as will be a big help.

[Alex_B]

You are running too rich, the timing needs setting first, then the mixture is adjusted to suit the timing :)

There will be a mixture screw on your carb which then adjusts the amount of fuel entering the engine, lean that off to reduce the amount of fuel. 

There is a nice way to check it, there will be a piston lifting pin on the carb which allows you to lift the carbs internal piston, if the revs rise, its rich, if they die and it tries to stall, its lean, if they drop a little but settle then its about right :) 

[JamesleppAFC]

Is the piston the bit you unscrew to put oil in the dash pot, and also the screw by the throttle cable that puts the revs up or down do I need to do anything with that? Hope that makes sense like I said I'm a fairly new mini driver.

[Alex_B]

Is the piston the bit you unscrew to put oil in the dash pot, and also the screw by the throttle cable that puts the revs up or down do I need to do anything with that? Hope that makes sense like I said I'm a fairly new mini driver.

That is the piston damper, the piston is inside the bell looking thing, 

the screw by the throttle cable is the idle adjustment, you will probably need to adjust it yes but after the mixture has been set, 

It normally is done in the order of timing, mixture, idle, choke, 

I cannot remember off the top of my head all the adjustments on an HIF type of carb (I run an HS4) but its all on here if you search, thats if you cannot find the mixture or want to identify each adjuster :) 

[JamesleppAFC]

Ok thanks for the help.