Greetings all. Spent some quality time with the Zed today, if you really wanna call it that. The first mission of the day was to get it started, its been sitting for ~3 months since it ran last, and it was a bit chilly today, about 40 degrees F. Well, mission failed. First thing, the choke cable broke. Took me a couple of hours and several adjusments, but I got that back together. So I apply the choke and turn the key, and it was making a very odd noise. Best way I can describe it is that it sounded like I could hear the piston moving inside of the cylinder with a rythmic burping sound. Might be normal, but I'd never heard it before. It was more quiet with less choke applied, and gone with 0 choke. I'm a newb to carbs, as this is the first vehicle I've owned that has them, but I've driven several and never heard this noise. Anybody have some insight?

Setup:'71 240z with triple Mikunis. Engine was rebuilt a few years ago but I still don't know the specs on the rebuild.

Might be piston slap. If it is it should be gone or much quieter when engine gets to normal temps. If the engine rebuild was a ring job then it is probably piston slap. I drove mine like this for years. Keeps the rpm's down until the pistons have expanded (warmed up). Forged pistons can do this also due to expansion differences vs cast.

My2C

Jim