mars23z

[mars23z]

Hello every one I m the new guy. I have a 1974 260z. It has the down draft SU carbs on it from an early 240 and i was wondering what kind of oil you put in them?(the carbs I mean)

[MikeW]

The factory spec is for 20W oil. The purpose of the oil is not for lubrication but to dampen the piston thus preventing it from opening too quickly during acceleration. Others have claimed success using automatic transmission fluid (ATF) but I've always just used the 20W. The most convenient way to get it is in this form:

http://www.wd40.com/PressRoom/StockImages/gifs_xl/3in1-p_3oz_motoroil.gif

[240ZX]

Just a technical note.....the SUs are a side draft carbs, not a down draft.

[mars23z]

Thanks for the input guys. I have a problem when I accelerate hard they seem to stick I dont know if its the carbs but it is annoying,

[240ZX]

Chris, If it feels like the throttle is trying to stick open under full pedal down accelleration, it may be a broken or worn out engine mount isolator. If the left hand insulator (engine mount) has failed, it will allow the engine to torque to the right. With the design of the early Z throttle linkage, in conjunction with a failed LH engine mount, the throttle will be forced to the full open position. Not a fun thing to have happen during a tense situation. I had this happen to me years ago. I replaced the engine mount.....problem gone! Just a thought!

[mars23z]

The throttle seems to stick after i let off almost like the choke is sticking it holds at about 3000 rpm for about 5 secs and then slowly drops