What air filter do you have???

[gator]

After removing the FI from my 77 280 and rebuilding SU's and installing them I am finding I need to adjust the carbs from time to time. I think I need new choke return springs and I can t seem to get the choke set up just right yet.

Ok .. my question is .. what type of air cleaner system do most of you have. The video from ZT states that the stock air cleaner is the best but I find it a pain in the a$$ to adjust carbs quickly with it there.

Looking forward to your responses.

Cheers ..Bruce

[Arne]

Well, I have the stock air cleaner, and yes it makes it difficult to adjust the carbs. But frankly, you shouldn't need to mess with them very often. Lots of people immediately start futzing with the carbs anytime the car does something different. But 95% of the time it's not the carbs and people just make the problem worse. Once they are properly set, it is best to leave them alone.

[SER240Z]

I have K&N's on my triples. I know that doesn't really pertain since you have SU's but the site was telling me that I should post somthing or engage in a conversation with someone so there it is.

I have seen the K&Ns for SU's though and I really liked them. Had I stayed with SU's I would have gotten them.

Scott

I have a ITG filter on my Roadster, but those are also Mikunis.

[beandip]

I agree with arne , I set my carbs and don't need to do anything but top off the dampner oil about 3 times a year . I am running a '82 ZX flat top engine With SUs , the air box is from a '72 and the element is a K&N .:rambo:

[gator]

yes .. I guess I just have not got them set propely yet. I have had a heck of a time this winter with the choke. I cant get the cable set up so that it returns when warm and the car really doenst run well when the choke is on. The back jet will stick on me and I need to get out after a few mins of running and reach under and push the jet up. I think the return springs need replacing. Since this is a 280, it was not made to have the choke in it. I have installed the choke lever in the console from a 240. You would think this would work wouldnt you?

The other thing that I notice is that the return pipe that comes into the carb from the valve cover, directs fumes into the back carb only. Why is this?? Why would it not be made to return this into the filter box? I have found a build-up of "sledge) from this and at one point this winter the back carb froze up on me. Could be that the motor is in need of an overhaul ??? Valve blow-by ??

[montoya_fan01]

Have the carbs been rebuilt?

Sounds like maybe the nozzle on the back carb is sticking, which the choke cable cannot overcome. The nozzle need to move freely.

[gator]

yep ..just did them. Where is the cable meant to be tightened? Should the cable be set so that the nozzle is just about to move? It seems to me that if I tighthen the cables where the arms are when the spring returns them, I then dont get the choke to open very much. And another question .. how far open should the choke go? Should the cable move the nozzle all the way down. half way ? .. ZT didnt seem to go into choke settings .. but I may have missed it when I was getting a beer from the fridge.

Thanks guys .. Your a great help. I have taken the car off the road for now till I sort out the little problems. I can walk to work so it is all good.

Cheers

[Arne]

Are your SUs three screw, or four screw? Since you say the carbs are rebuilt, I'd suspect that the nozzle in the rear carb isn't centered well, and is binding. That is adjustable on the four screw SUs, but not on the three screw, IIRC.

I'd be wary of going to some other kind of air cleaner just for this issue, as I'd fear that the other types might be more prone to icing up in your climate. A better solution would be to really fix the problem, so that you can keep the factory air cleaner.

[gator]

3 screw .. I had them working perfectly whwn they were put on. I followed the ZT video pretty closely. I did set the float different as I found the measurement he showed to be wrong for my carbs. I will take this nozzle apart again and re-grease it and re-center it. I dont think the car is running properly when the choke is on yet either.

Anyone have any answers about the gunk coming in from the valve cover? I often wonder about this. Why does it get directed onto the back carb? I am thinking about cutting the diverter pipe so that the fumes go into the air box.

[montoya_fan01]

Anyone have any answers about the gunk coming in from the valve cover? I often wonder about this. Why does it get directed onto the back carb? I am thinking about cutting the diverter pipe so that the fumes go into the air box.

Pictures? I'm only familiar w/ the 240Z set up. As for where it is directed on a 240Z, I don't know the "why" of it, but it works fine for me. Yeah rear of air cleaner gets a bit dirtier but it doesn't seem to affect operation and I wipe it clean a couple of times a year.

I wouldn't go cutting anything. Nissan did it that way for a reason, and it should work as designed.

[jackboxxx]

After removing the FI from my 77 280 and rebuilding SU's and installing them I am finding I need to adjust the carbs from time to time. I think I need new choke return springs and I can t seem to get the choke set up just right yet.

Ok .. my question is .. what type of air cleaner system do most of you have. The video from ZT states that the stock air cleaner is the best but I find it a pain in the a$$ to adjust carbs quickly with it there.

Looking forward to your responses.

Cheers ..Bruce

Guess you could call me a K&N fan the round ones below are supposed to be capable of some ungodly CFM airflow above a 1000ea. ...which is great because SU's cant digest that much It feels the same with them on as when im running straight air horns..

<a href="http://img402.imageshack.us/my.php?image=p62100027uf.jpg" target="_blank"><img src="http://img402.imageshack.us/img402/4996/p62100027uf.th.jpg" border="0" /></a>

<a href="http://img196.imageshack.us/my.php?image=p61800279oz.jpg" target="_blank"><img src="http://img196.imageshack.us/img196/1033/p61800279oz.th.jpg" border="0" /></a>

[jackboxxx]

Anyone have any answers about the gunk coming in from the valve cover? I often wonder about this. Why does it get directed onto the back carb? I am thinking about cutting the diverter pipe so that the fumes go into the air box.

Im thinking the rear carb gets dirtyer because of the airflow coming into the air cleaner?