Hey guys - so i just put in a 'new' 73 engine in my 74 cb750...everything went real smooth, and it even fired up on the first push of the starter....but #4 still isnt firing at idle...it wasnt even going at full throttle, until i dropped the bowl (PD42a carbs btw) and found that when i removed the main jet and screw to ensure they were clean, this one managed to get me to forget to tighten it down, and was thusly sittiing the bottom of the bowl, mocking me. screwed it back in, and i then had a working cylinder, but only at open throttle...the idle jet is was clean, and was then cleaned again and carefully pressed back in place....all four carbs were just synched and balanced. spark plug is good and showing good spark when held up against the engine...i thought maybe a low float level could be causing this, so i removed the float completely, put the bowl back on, but had no luck...running out of things to check....ideas?
