Hi. First post. I have an old TCM forklift with a Nissan petrol/gas engine. Runs fine on compresssed gas (LPG) but won't run properly on petrol. I took the carby off - cleaned out all the ports and float, etc. Reinstalled it today. It will only run (kind of) when I cover the air intake - more specifically the two tubes that stick out into the air intake. I'm guessing this means there's an air leak of some sort in the carby or the hole between the float chamber and intake is blokked or too small. Any idea where i should look? Any advice?? Thanks!