hi guys,i need to borrow some of your thoughts,iv done a head rebuild,got everything back together,put my new ss mani and downopipe on and i messed about with my carb(big,rookie mistake)now its backfiring spitting fuel and bogging out,i cant get any power out of it whatso ever,i started the car straight after i put the head back on and it worked nice(a tiny bit of smoke),the weekend after is when i put the mani on and messed with the carb?im stumped. any help appreciated.oh and its a D15B2 single cam.carb.thanks in advane

 

any one?

 

Did you mess with the needle valves on the carb? Just wondering if they've been inadvertently opened up too much (or missing).

 

There's a host of 'potential' issues in a carburetor. Needle valves could be set wrong (or not there, as mentioned above), jet sizes could be wrong (causing all sorts of issues), or jets could be damaged (if you were toying with them, although this seems less likely. You'd have had to have been trying to poke through the jets with something).

Even the fuel float level being set wrong can cause a pile of weird issues. :/ Without the carb in my hands its nothing more than guessing from me at this point though, sorry.

 

thanks for the replies,its the float i have been messing with,also the choke,i dont know where anything else is to adjust,if that makes sense.wher is the fuel and air mixture screws on these carbs?cheers

 

I'd get the float right before anything else. Carbs are very sensitive to adjustments so don't do anything to them w/o the right advice.

It sounds like the float is too high.

 

il try adjusting the float then would this cause the carb to smoke

 

If you're that unfamiliar with the carb that you were 'just messing with things' in a hope to make it better .... I'd strongly suggest taking it to a shop to have it rebuilt properly.

There's not that much to most carb systems, but each one is a little different from the next. Get that float level set right; too high will cause you to run rich, and too low will make you run lean, both of which can throw a whole host of other symptoms. If you haven't messed with the mixture screws yet, don't even worry about them until float levels are right.

 

thanks for the reply,if the float level is wrong(which it is now)would it cause smoke?thanks

 

Backfiring and spitting fuel can happen if the float is too high to the point of overflowing the bowl. That will put way too much gas into the engine and cause black smoke from it being very rich.