1972 Float Adjustment ...

[NVZEE]

To de-clutter this thread a tad, the up-to-the-minute info from Z Therapy is that they have not offered Grose Jets in years. What's being discussed here is the older vs the current replacement version of the standard SU needle valve . The new one comes from a different source and is a little different in design. This photo compares the current version on the left to the OEM valve. Reference to Grose Jets in the ZTherapy video is outdated and should be treated as such. The Grose Jet is an entirely different critter.

Edited February 23, 2018 by NVZEE

[siteunseen]

I wonder why they won't put a piece of paper in with their rebuild kit explaining that? I set mine the way the dvd shows and my car ran like $^!# for a year until someone mentioned it in a post. 

 

[jalexquijano]

Until this moment nobody has come with a precise response regarding from where to where is the .55 inch, 9/16  or 14mm measured? Is the measurement taken with the tang barely touching the neddle pin or with its weight on.  I measure it with the tang barely touching the needle pin and the mixture at 2.5 turns clockwise is still lean. Please see my post #156 for pictures as reference. Am i still to lean? Should i lower it?

Edited February 23, 2018 by jalexquijano

[Bruce Palmer]

On 2/13/2018 at 3:29 PM, jalexquijano said:

Thats what i meant the measurement of the 0.55 inch gap is taken with the bracket just on top of the pin and not depressing it. You need to be clear. The dvd is not clear and asidea from that it refers to grose jets and not needle valve.

And believe me I do apologize for this problem we seem to carry forward showing the lid/float turned upside down like this. This was shown by the original owner of ZTherapy using Grose Jets which we haven't been able to get for about 14 years. Can I get the video fixed to reflect how to do it with needles and seats? Not so far.....With needles and seats with the tiny spring inside, the weight of the float will over power the spring and your float level will be tits right out of the chute. Turn the damn thing over blow lightly into the fuel inlet tube while moving the float toward the lid. When the needle closes you should feel resistance to your breath. That's where your measurement should take place. Bend the tang on the float to get that gap from the top of the float to the bottom of the lid. Once you get both set the same, put your hands in your pockets and back away.

THEN: You start tuning the carbs. First thing is THAT 2 1/2 TURN THING is ONLY a starting point. Steve sets our "out the door REMANS" at 2 1/2. Most any motor (or engine for you sticklers) will start at 2 1/2 turns down but almost assuredly will end up up or down from there BASED ON THE MOTOR. Set the mixture and balance and go use your butt dyno to make 'er run. Keep tweaking til it runs.

I do have to ask: who's lid is this in the photo? Don't even tell me the caps are left on the overflows for running.

I'm going to my room......

 

[Mark Maras]

  Bruce beat me to it. Thanks Bruce.

Let's try this. It may be an easy way to support the floats while checking the height. Remove the gasket from the float cover. You'll be using the lid surface for your float measurement reference point. Cut two strips of something flat (plastic, card stock, shim stock, etc,into strips about 3" long. One strip will be 9/16" wide, and the other 5/8" wide. With the float lid inverted, insert the 9/16" strip under the unsupported end of the float, resting on the lid gasket surface and blow thru the fuel inlet fitting.  The 9/16" strip, then the 5/8" strip. Adjust the float tangs until there is air flow past the needle and seat using the 5/8" strip but no air flow using the 9/16" strip. Hopefully the 5/8" and the 9/16" strips will act like a go, no go feeler gauge. This method should work for getting them close. We'll check the fuel level in the nozzles, when you get it reassembled, to be sure they're correct.

[Stanley]

4 hours ago, DaveR said:

2) From there back the nozzles down a full 10 turns of the fuel adjustment. Its quite far.

That's what I thought I remembered from a few years back. Not 2 1/2 turns down. Didn't want to post about it since I wasn't sure and haven't tried that method. I don't know where the fuel level in the bowls will end up. I know there's a Nissan tech. bulletin about float bowl fuel levels but I can't find my digital copy. IIRC it's 22 mm down from inside of lid to fuel level for the rear and 25 mm down for the front, please verify this. Page EF-25 of the '72 FSM says it's 23 mm down (for both carbs) ; the tech bulletin corrects this for the later carbs with different front and rear fuel levels. Hope someone posts that bulletin again or has a link to the original posting. Since there's no way to measure from underside of the lid to fuel level we need to use micrometer to measure from underside of lid to top of the bowl, which is easy to measure to.

Using the "same level of fuel in the nozzles" method will get the fuel lever difference between front and rear bowls correct if the car is on a level pavement, but it won't necessarily get the absolute level from the lid correct unless the "10 turns down" has been adjusted to work with revised fuel levels in the tech bulletin.

Maybe 2 1/2 turns down is correct for the nozzle method, but if you're wrong fuel level will be way too high and run out the carb and lid vents, so be ready to switch your engine off fast if it does. If you have the sightglasses, it might be better to use that for a ballpark setting, and then use the nozzle method to get them perfect. Since the nozzle method gets the front/rear difference correct, you only need to check the rear carb to verify correct fuel height. Mark's post a minute ago would also be OK for ballpark.

Edited February 23, 2018 by Stanley

[NVZEE]

Thanks for joining in, Bruce. Adding this to the thread gives everyone a fresh reference on how to approach a persistent issue. You should come out of your room more often ?

[Mark Maras]

 Someone correct me if I'm wrong. I'm assuming the 10 turn down method is viewed with the float cover removed and the 2 1/2 turn down method is with the floats installed. More assumption now, that would mean the installing the lids (floats) would raise the fuel level in the bowls about 7 1/2 turns. is this a correct assumption or am I missing something?

[Stanley]

Dunno

[siteunseen]

40 minutes ago, Bruce Palmer said:

And believe me I do apologize for this problem we seem to carry forward showing the lid/float turned upside down like this. This was shown by the original owner of ZTherapy using Grose Jets which we haven't been able to get for about 14 years. Can I get the video fixed to reflect how to do it with needles and seats? Not so far.....With needles and seats with the tiny spring inside, the weight of the float will over power the spring and your float level will be tits right out of the chute. Turn the damn thing over blow lightly into the fuel inlet tube while moving the float toward the lid. When the needle closes you should feel resistance to your breath. That's where your measurement should take place. Bend the tang on the float to get that gap from the top of the float to the bottom of the lid. Once you get both set the same, put your hands in your pockets and back away.

THEN: You start tuning the carbs. First thing is THAT 2 1/2 TURN THING is ONLY a starting point. Steve sets our "out the door REMANS" at 2 1/2. Most any motor (or engine for you sticklers) will start at 2 1/2 turns down but almost assuredly will end up up or down from there BASED ON THE MOTOR. Set the mixture and balance and go use your butt dyno to make 'er run. Keep tweaking til it runs.

I do have to ask: who's lid is this in the photo? Don't even tell me the caps are left on the overflows for running.

I'm going to my room......

 

Print that and make a copy to go with each rebuild kit.  You would save everybody that buys the kit a lot of headache with those instructions.

"Put your hands in your pockets and walk away" that's classic and should be the last sentence on every set of instructions.

[siteunseen]

37 minutes ago, Mark Maras said:

 Someone correct me if I'm wrong. I'm assuming the 10 turn down method is viewed with the float cover removed and the 2 1/2 turn down method is with the floats installed. More assumption now, that would mean the installing the lids (floats) would raise the fuel level in the bowls about 7 1/2 turns. is this a correct assumption or am I missing something?

I think they're saying the extra 7.5 turns down is that 1/16th you are talking about at 2.5 turns down? 

This simple thing people have done since they came off the boat has gotten knee deep on this thread and he has 3 active now. I think it'd be easier to raise the plane ticket money and send Mark down there and have boots/wrenches on the ground.

[jalexquijano]

Ztherapy should update that 18 years old video and do a remake of the .55 inch gap with needle valves.