Please excuse me asking this question on the locost site but someone may have an answer. I have bike carbs fitted to my Skoda Estelle trials car engine. I am running a Filter King to regulate the fuel pressure to the carbs. The pressure regulation was pre-set when i got the filter (new off ebay) What would the indications be that the pressure needs to be adjusted? I am getting some poor running at very high revs that may be fuel starvation but it could also be other things. If the fuel pressure is not restricted enough do I get flooding of the fuel chambers or if it is too low would I get starvation at high revs?

I tried a filter king regulator with my CBR600 carbs - never worked very well. I think that it struggles to supply low pressures at sufficient volume.

Now I run a bike pump that originally came from a large Kawasaki that had carbs (NOT a fuel-injected bike!) and I don't use a regulator at all.

Hmmn, so many possible answers...

Do you have access to a wideband O2 sensor sensor setup and a knowledgeable friend, or perhaps a decent local tuning shop with a rolling road?

Bike carbs don't generally need very high fuel pressure and too much will overwhelm the float and needle valve and give you all sorts of low speed flooding issues.

It's more likely that the needle profile is lean at the top end and you need to fit new ones, which will be fairly inexpensive but tough to get right by guessing.

Cheers, Ted

kawasaki carbs only want about 1.5 psi i think.