Andrews carb issue

[speedracer1414]

Hi i just got my first 72 240z and i have flat top dual su carbs on it. it wont fire up and idle...but turns over...Should i rebuild and keep?i have no idea on how to sync and tune the SU carbs either, or should i go with dual webers or a 4banger?

[MikeRL411]

Putting a 4 banger in a 1972 240Z is a desecration!

[ggzilla]

4banger is a 4-cylinder engine. Yes its a desecration to put a 4banger in a Z. If you meant a 4-barrel carburetor, well the factory 240Z carburetors are better.

 

 

But first, figure out what the problem is.

[ggzilla]

Hi i just got my first 72 240z ... it wont fire up and idle...but turns over...Should i rebuild and keep?

Only rebuild the engine if it needs rebuilding. Perfectly good engines sometime won't fire up.

 

First, check for spark. If you haven't replaced the points set (points & condensor) in the last 12 months, do that now. Then see if it fires up.

[ggzilla]

i just got my first 72 240z and i have flat top dual su carbs on it.

Early 1972 240Z came from the factory with round-top SU-style Hitachis. Late 1972 240Z came with flat-top Hitachis. The late style carburetors are not as good, but they will start the engine no problems.

 

Before you decide what to do with the carbs, find out and fix the starting problem.

[LenRobertson]

Do a search on YouTube for Datsun SU carbs or similar search terms. There are several vids on there on SUs. No guarantee you will figure out your problem from watching them, but it is a start. Dual Webers are probably going to be more complicated to tune unless you find a rebuilt set already jetted for your engine, and that will pricey. Figuring out the problem with what you already have seems easier and cheaper. Z-Therapy sells a good DVD on the care and feeding of SUs if you really want to get educated on them.

 

Len