Do Z therapy carbs come balanced and ready to bolt on? I would guess not, as no two engines are the same, but what adjustments are needed when bolting on carbs that you get back form Z therapy.

My set took a little tweaking, but the car started fine with them right out of the box (once I got my timing straight). Minor adjustments were all they needed "out of the box". The ZTherapy video is great and walks you right through tuning and balancing.

What Paul said.......

I am thinking of getting a set from Z Therapy as my current carbs have air leaks at the throttle shafts.

Question: Did anyone order oversized needles with their new carbs? If you did what size did you get and what adjustments did you need to make to the engine. Does it make a big difference in the performance of the engine?

Thanks for any and all replies!

There really isn't much need for a lot of needle choices. There basically are 2 choices. The stock needles tend to run a little lean but basically are fine. The SM needle is a European SU grind that was identified back in the 70s as a performace step up and has been very popular ever since. We will supply either per the customer's request. The carb / Z car package has been very well sorted out for years and once a set of these Hitachis are returned to square one i.e. everything new, they are the easiest carbs in the world to keep up with.

I have to agree the CD from ZTherapy is worth the $. I'm not a mechanical person but atfer getting tired of changing fouled plugs, bad mileage, running like crap and the smell of gas coming out of my exhaust I bought it. I was able to tune my carbs by myself and it now runs great. Thanks Dave

There really isn't much need for a lot of needle choices. There basically are 2 choices. The stock needles tend to run a little lean but basically are fine. The SM needle is a European SU grind that was identified back in the 70s as a performace step up and has been very popular ever since. We will supply either per the customer's request. The carb / Z car package has been very well sorted out for years and once a set of these Hitachis are returned to square one i.e. everything new, they are the easiest carbs in the world to keep up with.

Hi Bruce,

Thanks for the information. I will be giving you a call in the next week or so to discuss. The car is in hibernation for the winter. Good time to remove the carbs and send them off to your shop!

Marc

Edited January 8, 200916 yr by mgmoreau

I tried 47s ,27s, 58s, SMs, and found the 54s to work the best for me. They run a little rich on the top end but great from idle on up. 47s too rich, 27s too lean, 58s lean,SMs vary rich. This is on a ZX motor with a mild cam , headers and 2 1/2'' exhaust. I am by no means a expert but this is what works for me. My '73 is exempt from emission testing

however I took my Z and had it tested by the state DEQ testing station. I passed with zero emissions equipment installed. I was a little on the rich side at idle but she cleaned up on the high RPM test. Go figure. above all I am pleased with the performance. 54s are the stock needles used on the L-24 engines !

Gary

Hi Bruce,

Thanks for the information. I will be giving you a call in the next week or so to discuss. The car is in hibernation for the winter. Good time to remove the carbs and send them off to your shop!

Marc

Marc,

If you want to see the ZTherapy carbs in action, take a ride from Lincoln to Taunton. That's only about a half hour or so. Of course, my cars not running right now either, its all torn apart for the Winter upgrades. But I'll have it running again in a week or two.

The ZTherapy carbs are awesome. Once I dialed them with the help of the video, I haven't had to adjust them at all. The car starts easy, idles great and pulls hard. Of course, next year with the 4.11, 5-speed and ZX dizzy upgrades complete, I bet it pulls a lot harder.:bandit:

My 72 240Z has SU's. The car takes a bit to start after sitting for a few days.

I've been assuming this is a case of waiting for gas to the fuel rail / carbs.

I have a clear in-line fuel filter. The filter always looks less than half full of gas.

Is this normal ?

Jay

Not just a Z - zdisease

My 72 240Z has SU's. The car takes a bit to start after sitting for a few days.

I've been assuming this is a case of waiting for gas to the fuel rail / carbs.

I have a clear in-line fuel filter. The filter always looks less than half full of gas.

Is this normal ?

Jay

Not just a Z - zdisease

I have the same issue, and rebuilt my '72 240Z's Hitachi SU's with a ZTherapy kit with SM needles. It runs great now with plenty of power, decent mileage, and good driveablity, but it still takes a little coaxing to start it when it has sat for a couple days. I think its just a matter of getting the gas pumped up to the carbs. Since Steve Epperly at ZTherapy helped me to adjust my chokes correctly, it starts WAY better than it did before.

Greg

Jay.....Your problem is most likely adjustment in the choke cables. Get a buddy to pull the choke lever back while you are looking under the carbs to make sure the chokes are engaging properly. You shouldn't have to "pump her up " each time she sits! Also as the "Just SU's" tape will show you, make sure they are closing when you push the lever forward!