carb jet sizes / float levels

[SavannahZ]

Hi,

I took apart part of my carbs today to find out that I have different size jets. I also noticed that the towers(?) that hold the float pins are different heights. The smaller of the towers had the smaller jet.

Is this from two different carbs?

Also, when I go to set my float level should I compensate for the different heights or just set them both to 5.5mm? Obviously, when I hold them next to each other to see if they are equal, even if they are both at 5.5, they won't be.

I also looked at my needles and they are N58. Does anybody else run these?

On a side note, the car does run good with a lot of power and good idle.

[Arne]

Seem to recall something on ZTherapy's site about the different ear sizes. Certain years had different float caps for front and rear carbs. The different length needle jet may have been to go with that, don't know.

But regardless, the needle jets are only to open the float inlet, they have nothing to do with the mixture. (Not a true jet, in the normal carb meaning.) You should still set the float level even in both bowls.

[SavannahZ]

You are absolutely right arne. I had looked over their site before posting this, but I missed that part. It is amazing how many parts they mixed together.

Thanks again!

[beandip]

I have a set of #58s , came in a set of 3 screws I bought. I compaired them to a set of 54s and they are leaner needles . I bought the carbs from a area that is high altitude and most likely ran well there . I am down to sea level and need a richer needle I bought set of 27s from Nissan , but cant pick them up untill the weekend . So I am going to try the 54s then the 27s . I have a new set of SMs I will sell for $15.00 the pair , I installed them but never put the carbs on the engine , and pulled them . Gary Nissan sells the needles for $18.90 ea.

[=Enigma=]

I took the Ztherapy info to mean that the different size ears where contained on a single float bowl cover. It looks to me like you may have two different version carbs. And that's all I'm gonna say as a newbie who has yet to crack his own carbs.

[Arne]

I took the Ztherapy info to mean that the different size ears where contained on a single float bowl cover. It looks to me like you may have two different version carbs. And that's all I'm gonna say as a newbie who has yet to crack his own carbs.

Could be, my carbs are early ones and both float covers are the same. But I also note that MSA's catalog lists a different "needle valve" (proper term for what we have been calling "jets") for the front and rear carbs for a '72. So I'm leaning towards the original poster having a matched pair of '72 carbs.