Carburetor Re-assembly

This afternoon I rebuilt the carbs using the cleaned-up parts, refurbished bodies from Keith Williams, new nozzles from Z-Therapy, and new floats, gaskets, fuel pipes, needles, banjo bolts, and float screens from Nissan.

I was surprised that the carbs went together fairly easily. Basically it was just a matter of reversing the process I had gone through to break them down. I began with the float bowls. The drain and fuel inlet bolts threaded into the bottom of the float bowls. I used a 12 mm socket with hand-pressure to tighten them. I didn’t want to use to much pressure because the bolts were brass and the bowls are aluminum.

I then tightened fuel-supply bolt up using a 10 mm wrench. Next I moved on to the bolt that attaches the float bowl to the carb body.

One end threads into the bowl, through the rubber grommet and the fitting washer. I tightened this down using a 14 mm wrench.

Then I moved on to the lid of the float bowl. I re-used the old float nozzles, because they appear to be in good shape and the new ones I ordered were the wrong size. I tightened the nozzles into the lid, gently using a 10 mm wrench.

Although the old floats were in good shape, I installed my new floats using the original pins. I made sure the floats on each lid sat in similar positions once installed.

Then I placed the new gasket in place and bolted the lids onto the float bowls using the original bolts. I had wanted to replace all of the bolts with shiny yellow zinc ones but they proved to be impossible to find.

I bolted the assembled float bowl to the carb body using the bolt already installed on the bowl. I used a 10 mm socket on the nut on the opposite end of the bolt. Then I attached the idle-adjustment bolts to the bottom of the carb bodies.

First I threaded in the shaft and tightened it using a 19 mm wrench and then I tightened the knob and spring into the shaft, all the way down to the tightest setting.

On the bottom of the idle-adjust knob I cleaned out the nozzle aperture using a couple of Q-Tips. Then I inserted the nozzle.

I attached the new J-shaped fuel pipe first to the nozzle and then to the fuel-outlet on the float bowl.

Then I installed the new jet needles. I used new N-17 needles from Nissan. In order to set the needles, I used the following procedure on each carb:

  1. Loosen the set-screw on the piston.
  2. Loosely install the needle into the piston.
  3. Drop the piston into the body and push it all the way down until the needle bottoms out in the nozzle (holding the nozzle up tight against the body), forcing the needle upwards into the piston.
  4. Remove the piston and tighten down the set-screw to secure the needle in place.

Then I placed the original plastic washers and piston springs back onto the pistons.

And placed the domes over the pistons and bolted them into the bodies using the original bolts.

Next I replaced the dome caps and fit new fuel screens on the banjo bolts.

And I bolted together the fuel inlet piece and bolted it onto the carbs using the banjo bolt, which I tightened using a 17 mm socket.

Lastly I added the bolt that acts as a stop for the throttle shaft. Here is a picture of the reassembled carburetors.

All that remains is to put the arms that mechanically operate the nozzles back together.

Carburetor Parts Cleaning

This morning I cleaned-up the bits and pieces of the carburetors in preparation for reassembly. I used some Simple Green and scouring pads. After allowing the parts to air-dry I then sprayed on some metal polish and buffed the parts.

Overall I’d characterize the results as “good.” The parts came clean and were sufficiently de-greased. The polish worked okay and some of the parts became nice and shiny. The only problem was in parts that had rust or other blemishes on the metal. This process did not address those types of flaws. Originally I had planned to send many of the pieces off to be sand-blasted and re-coated in zinc. This would have resulted in a much better finish. However, I am too afraid to send all those bits away because they may come back in one big pile and I’d never get the carbs back together again.

Here is a picture of the parts I cleaned and one of the piston springs soaking in Simple Green.

Here are before and after shots of the arm that actuates the choke. You can see the blemishes in the metal remain.

Here are the throttle-adjustment bolts, which came out much better.

Finally, here are the bolts that connect the float bowls to the carb bodies before (left) and after (right).

First Frame Cleaning

This afternoon, after removing the rear suspension, I decided to take a first pass at cleaning up the frame. The frame was covered in dirt, road grime, and a lot of grease and oily residue in the middle. Before I paint the frame I will need to clean it up at least a couple of more times. I used a rag, hot water, and Simple Green, which in my experience is a good cleaner and degreaser (and it is biodegradable). I also employed a wire brush to get some of the caked-on grease loose.

I wanted to clean up the frame while it still had one pair of wheels on it so it could be easily rolled outside. I’m not sure how heavy the frame will be once it is fully stripped, but as of now I can wheel it around by picking up the rear end myself, wheelbarrow-style.

First I removed the motor mounts, which were mounted by two 1/2″ bolts.

After scrubbing for a while and spraying at high-pressure with the hose the frame came fairly clean. Not totally clean, but much cleaner than it started. As I said, it will take two to three washings to really get it clean. I tried to clean up the front suspension and steering components, which were covered in grease, while I was at it.

The “X” shaped crossbrace in the middle of the frame was very greasy, and still has some grease and grime caked into the nooks and crannies. But I did make a lot of progress.

Rear End Disassembly

Today I tore down the rear suspension and removed the differential and rear axle. Progress!

Here are some pictures of the rear suspension before I began. The rear axle:

And a couple of close-ups of the right rear suspension components from the front and rear:

The suspension is held together largely by a plate that bolts over the axle and through the leaf spring, and also bolts onto the rear shocks. Underneath this plate are the five primary bolts that hold everything together.

The first order of business was to remove the wheels. I broke loose the lug nuts using a breaker bar 19 mm socket with the car resting on the ground. I then jacked-up the car and supported it using my heavy-duty jack stands under the rear part of the frame.

I finished removing the lugs using a socket wrench and the 19 mm socket, then carefully lifted the wheels off the lugs and pulled the wheels.

Here are a couple of shots of the brake drums and rear suspension with the wheels removed.

The weight of the wheel assembly caused it to drop down, stretching and placing tension on the leaf springs. I used the jack to apply upward pressure underneath the suspension plate, and placed another jack stand under the leaf spring to relieve this pressure. I applied enough upward force to raise the wheel assembly but not enough to raise the frame off the larger jack stands placed at the rear. I then jacked-up the differential, but not enough to raise the leaf spring off its jack stand, and placed a final jack stand under the differential. This ensured that no matter what I unbolted, I shouldn’t have anything heavy falling to the ground (or onto my lower extremities). Safety first!

The plate that all of the suspension components bolt to is held to the rear axle by two threaded u-shaped clips that bolt over the axle and through the plate. Four nuts hold these clips in place from underneath the plate. I removed all four of these nuts using a 15 mm socket. I tapped the clips from below using a mallet to get them free.

I removed the clips and then was able to pull the bumpstops off the axle.

Underneath, at the center of the plate is another nut that mounts on a threaded stud that protrudes through a hole in the leaf spring. I began to loosen this nut using a 12 mm socket and before it was off the plate came free and slid down the shock toward the ground.

Next I removed the nuts that secured the top of the shock. The nut was larger than my largest socket, so I used an adjustable wrench. With the nut removed I slid the shock and its bushing off the stud onto which it was mounted.

I then jacked up the differential about a half an inch (actually I just lifted it up using brute strength and raised the height of the jack stand) which raised the axle off the leaf spring.

I was then able to pop off the lower metal piece that bolted the leaf spring to the whole assembly, leaving the leaf spring mounted only to the frame at the front and rear.

At the rear the leaf spring is bolted to the frame by two bolts through a bracket. I unbolted the two nuts from the bolts using an 18 mm socket.

From the inside I then removed the bracket’s cover plate and from the outside I removed the bracket itself.

The leaf spring is the upper loop and is held to the frame by the lower bracket bolt through the lower loop of the scroll.

At the front there was a single bolt through the frame that mounted the leaf spring. I loosened the nut on this bolt using an 18 mm socket and then tapped the bolt out.

That released the leaf spring from the frame. I next removed the scroll-shaped hangers that mount the leaf springs in the rear. There was one bolt on the inside, which I removed using a 15 mm socket.

On the outside of the frame the scrolls were mounted by another bolt. I used a 15 mm ratcheting wrench on the nut and 15 mm wrench to hold the bolt.

On the passenger side only, later roadsters have a torque strut bar that helps to prevent the frame from racking when the car puts power to the wheels. I removed this, which is bolted through a bracket on the rear axel. I used a 19 mm socket and wrench to remove the bolt.

I unbolted the front of the torque strut bar the same way and pulled the bar off.

That concluded the disassembly of the rear suspension and I was able to roll the axle and differential away, leaving the naked frame.

Rear Brake Line Removal

This afternoon I removed the hard brake line that feeds brake fluid to the rear brakes. The brake line was composed of three sections: a front section that curved upwards into the engine bay; a straight middle section that ran from the front through the “X” cross brace of the frame; and a rear section that ran up over the rear axle to a soft rubber line.

I began by removing the front section of brake line from the mid-section. I used a 7/16″ wrench and a 9/16″ wrench to unbolt the coupling that held the two lines together. The midsection of the brake line ran the length of the frame, just inside the main frame member on the passenger’s side of the car.

The middle section was held to the frame by several clips, which could be bent down to free the line, and terminated at the beginning of the rear section of the brake line.

I removed the mid-section from the rear section of the brake line where they met through a bracket welded to the frame. To remove the coupling that held the mid-section to the rear section I used a 3/4″ wrench to hold the coupling and a 7/16″ wrench to loosen it.

The middle section went through the frame in some very narrow spaces between the main frame front-to-back member and the X brace. The gap between these was so small that it was impossible to pull the middle brake line section out due to the size of the couplings on either end of the line. So I resorted to cutting the middle section in order to pull it free. I will be fabricating a new middle section of brake line at a minimum.

The other end of the rear section connected to a soft line that fed brake fluid down to a splitter mounted on the differential. I freed the front of the rear section from the frame bracket by removing the clip that held the coupling to the bracket. The rear end of the rear section I had removed from the soft line several weeks earlier, in preparation for removing the body from the frame (in retrospect that was not necessary at that time).

With the front and rear of the rear brake line section free I just pulled it through the grommet in the frame to get that section of line off the frame.

I then removed the top of the soft brake line (the one that the rear section of hard line was previously connected to) by removing the clip and bracket that held it to small metal bracket welded to the frame. These pieces I just removed by prying with a screwdriver.

This enabled me to remove the top section of the soft (rubber) rear brake line.

The bottom of the soft line connected into a splitter that fed brake fluid to the drum brakes on either of the rear wheels. I disconnected both of the outbound hard lines from the two sides of the splitter, using a 7/16″ wrench.

Next I removed the bolt that mounted the splitter into the differential, using a 1/2″ socket.

The hard lines that went to each of the brake cylinders on the rear wheels were held in place with some more clips.

Those lines then connected to the rear brakes via some 7/16″ couplings, which I left connected for the time being.

I will leave those remaining hard brake lines in place on the rear axle, which I will remove all in one piece.

Fuel Lines, Removal

This morning I removed the hard fuel lines from the frame. I need to strip the frame down in order to clean it up and paint it.

There were two fuel lines that run from the gas tank up to the right side of the engine bay, where soft lines run over towards the carburetors. The smaller (in diameter) of the two lines is the fuel supply line and the fatter one is the fuel return line. Each of the two lines were in two sections, a short section in the front that ran up into the engine bay and a longer straight section that ran back along the frame and curved over and connected to the fuel tank at the rear of the car.

I began by removing the soft line from the front end of the fuel supply line. There was a whole assembly with a fuel filter and fuel pressure adjustment gauge that I removed.

Below is a shot of the front sections of the fuel lines. I first removed the front portion of the fuel supply line. The front and rear sections of fuel line were coupled together. To loosen the couplings I used a 1/2″ wrench to hold the center section of the coupling and a 9/16″ wrench to loosen the coupling itself.

With the fuel supply front section freed up, I disconnected the front section of the fuel return line in the same manner. The flue return line was located just below the fuel supply line. I used a 1/2″ wrench again on the middle section of the coupling, and a 5/8″ wrench on the coupling collar.

This allowed me to remove those front sections of fuel line and start working on removing the rear sections. There was some fuel left in the lines which began to pour out when I started tipping the lines. I caught it in a cup–more fuel for the lawn mower!

The straight sections of the fuel lines were held to the frame by several tabs, which I bent down to free up the lines using a flat-head screwdriver. Above the rear wheels there was a lot of grit built up on the frame over the fuel lines.

You can see where the fuel lines curve around and meet the fuel tank behind the rear axle.

With all of the frame tabs loosened I then pulled the fuel lines back towards the rear of the car, removing them from the frame. I had to work the portions that attach to the gas tank over towards the outside of the frame in order to pull the lines off the frame. There was enough flexibility in the lines to work them off the frame in one piece.

New Hood

I bought this new old hood on ebay last week and it arrived today. It is from a 1970 roadster, but I’m told that it should fit my 1968 though the latching mechanism is slightly different.

My hood is in decent condition, but has a couple of issues. First, there is some damage from rust on the front right lip of the hood. Second, the car was fitted with hoodpins when I got it. I am definitely going to remove the hoodpins, which are not original, which would entail patching the silver dollar-sized holes in each upper corner of the hood. Third, the hood doesn’t fit quite right and is difficult to open because the top edge meets tightly up against the cowl. And fourth, my hood has the holes for the lettering that spells out “D A T S U N” patched over, while this one has the holes so I can re-mount that original logo on the car.

So I bought this hood for just shy of $100 shipped figuring the repair work to my old hood would be in that neighborhood anyway. If this one fits better it will be a bargain. We’ll see.

The new hood is in very good condition. It has some surface rust but is quite solid. No visible dings or dents on the top surface. It does have a bit of a deformation in the upper passenger-side corner, probably damage incurred during shipment. That should be easy enough to straighten out.

If the new hood doesn’t work out I can always repair and use the old one.

The Set-Up

I thought I’d take some time tonight to demonstrate exactly how I’m doing this restoration project within the confines of a (smallish) suburban two-car garage at the same time I maintain (relative) domestic tranquility.

The key to the whole operation is Mark Sedlack’s body stand, or more precisely, the wheels I’ve added to it. That enables me to monopolize only one half of the garage during the week and leave the other half open for parking. During the weekend we move all of the cars into the driveway so that I can use the whole garage for the project.

This is how the set-up looks for the most part during the week.

To work on the car I first roll the frame into the driveway, the roll the body stand over to the right and then roll the frame back into the left bay of the garage.

Then, at the end of the weekend, I simply roll the frame out into the driveway once again and then push the body stand back over into the left bay of the garage.

And then I push the frame back under the body stand, opening up the right bay of the garage for parking again.

I works pretty well and the loads are light enough for me to move the wheeled pieces around by myself.

Carb Bodies Return

Well my carburetor bodies didn’t stay in Vegas very long. Keith Williams e-mailed me Saturday to say he had received the bodies and already worked on them. He sent them back and I received them today. They look great and the throttle shafts no have no play in them whatsoever. He also sold me a pair of new throttle return springs, which are NLA from Nissan, for a couple of bucks.

I need to get my act together and get some of the bracket pieces plated so I can rebuild these carbs.