65 replies to this topic

[rodjr]

Hello all, 

Newbie to 521's and Datsun in general. I have been buying brand new compact trucks every few years for three decades and it is to the point now that it seems you can't buy just a TRUCK anymore. Power windows, extended cabs, automatic transmissions,  tv screens in the dash and bigger, bigger, bigger is just not for me.  I just wanted a SMALL truck. Even at my age i can muster the energy to crank the window all the way up by myself without getting winded, and i don't have to argue with the auto up/down about where i want the window positioned. I don't seem to experience the same aversion to the apparently major hassle of operating a clutch and gear selector that some do. I have no use for more than a total of 2 doors, and i have no idea what i am supposed to need or want an "extended cab" for.

 

So my new 1971 red 521 is in the garage. Picked it up last weekend, 115,000 orig miles, lot's good and some bad. 

The good: a.m radio works with the original speaker, dash is very good, runs nice, glass is great, grill and bumper nice, only one small dent. I would say 90% unmolested, stock hubcaps are perfect.

The bad: runs on when you shut it off, sloppy shifter (common as i understand it), somebody replaced the seat with a later seat and it is fixed with no sliders. Paint is faded and worn through to primer in places. Clutch not adjusted well, engages at the very top, no free play. Air cleaner is hacked, and window channels are done for.

 

I think i can handle figuring out the clutch as well as the shifter and i have already ordered bushings for that. I have not had time to look, but i am guessing the carb may have a cutoff that is not functioning, or too much timing causing the running on. I found some window channel on ebay.

 

I sure would like to find some original parts to rework for this truck, like the air cleaner, some seat sliders, a seat, and the tin piece that attaches to the manifold to get a functioning heat riser. The truck also came with a box of parts including a matchbox dizzy and i would like to find a factory T connector and coil to go with it.

If anyone knows of a good source for used parts for these i sure would be grateful, maybe a wrecking yard anywhere in the U.S. that is known to have one or two of these trucks on occasion or even that is Datsun specific? I have looked but google is not always better than first hand experience.

I would rather sink $30k into this 521 than a new thing they call a truck, at least the 521 will make me smile.

 

Tomorrow i am going to ditch my 2017 garbage barge of an overgrown small "truck" and pick up a basic commuter car and start working on my SMALL TRUCK.

 

[datzenmike]

Hi Rod, welcome to Ratsun.

 

Yes the tyranny of choice, too many things makes life more difficult instead of easier. I had a remote control side view mirror on my '70 Dart. Funny how my previous car, a '64 Dodge, mirror did not adjust without winding down the window, so once set, you tended to just leave it. So now I had a mirror that you could adjust from inside the car and I found every time I got in I would adjust it. In the morning you sat straighter so you adjust it, at night you're more tired and slouch, so you adjust it.....

 

Or it could just be that you long for an earlier time when things were simple. Like a Datsun. There wasn't much to them so less to go wrong. If you couldn't fix them you at least knew what was wrong with them.

 

 

We have a lot of 520/521 owners here so you'll have lots of people like yourself. Hell I owned a 6 year old '71 521 back in the '70s. Had it for 8-9 years.

 

Run on or dieseling.

The 521 didn't have an idle cut solenoid because it really didnm't need one, unlike the larger and later L20B engine that did have them. (perhaps an L20B has been swapped in???) Some things that might contribute to run on are...

 

Incorrect make of spark plugs and wrong make. Always use NGK plugs. I would guess B6ES but maybe someone else can say for sure.

Running over rich. Choke stuck on. Carburetor flooding or float set too high.

Too low an octane gas, or crappy cheap gas. Try a brand name.

Idle speed set too high

Idle mixture set too rich

 

Clutch.

It may be low on fluid.

It may have air trapped in it and need to be bled to get it out.

The clutch pedal should move about 1/16" with thumb pressure before there is firm resistance.

 

I used a coffee can and metalized hose the get the 'heat riser' working. Used wire to hold it in place. It worked until I could find one from a wrecking yard. No one makes them. It's a must have to prevent carb icing in cold damp weather.

 

If looking search our CLASSIFIEDS here...  http://community.rat...sort_order=desc  ... or post a want ad.

[bananahamuck]

I would comment but i see no pics to back up this outlandish claim of being in possession of a "521" as you put it.

 

 

 

[rodjr]

Ya, have not had a chance to get pics yet, brought it home in the dark and worked late all week. I will try to get a couple this weekend, then attempt to figure out how to post them here.

 

I have learned the name of the original owner which was inside the intact service booklet. The truck was purchased new within 30 miles of my house and has not a spec of dangerous rust anywhere including the floors. Some surface rust in the bed but nothing you could poke a hole in without a real hammer and a cold chisel. 

[flatcat19]

Waiting on pics.


The key to finding 521 parts is patience. I've been waiting for the same part from two different people for a while now...the hold up? Like yourself...lack of pics.

Kidding. Welcome to Ratsun.

[mrbigtanker]

Welcome aboard. Pictures are awesome. We love pictures.

[DanielC]

General 521 info.

The bolts on the body are SAE.  Measured in inches, fine thread.  The engine and transmission uses metric fasteners.  The brakes are NOT self adjusting, you have to adjust them, every oil change. 

The running on probably can be fixed by doing a tune up on the engine.  Tune up includes adjusting the valves, .010 intake, .012 exhaust, engine hot, setting the ignition timing, Timing is 10 degrees BTDC, and then setting idle speed and mixture..  I recommend you set the idle mixture with a vacuum gauge, and a tachometer that reads low RPM.  Disconnect the distributor vacuum hose, plug the line.  Tune for best idle at 750 RPM, and then turn in the idle mixture screw to drop the RPM to 700.  This must be done on a hot engine.

If you have not had a 521/L16 on the freeway before the engine is going to sound like it running way too high RPM, 60 MPH is about 4,000 RPM.  that is fine, it will run there all day long, and be happy.

 

The transmission does not have external linkage.  There is a rod that slides forward and aft, and it rotates slightly.  The rod has a finger on it that goes into a fork in the 1-2, 3-4, and reverse shift rails.  Most of the slop is on the end of the finger, where it goes into the forks on the shift rails.  You can shim the external parts just under the shifter boot, but not a lot.

 

The seat will be difficult, you need a narrow seat to fit in  a narrow cab.

 

On a stock 521 the slave cylinder has an adjustment.  It also has a spring to pull the clutch fork and throwout bearing away from the pressure plate.  There needs to be some freeplay, about 1/16 of an inch before the throwout bearing makes contact with the pressure plate.

 

The heat riser for the exhaust manifold is not likely to be found.   Sheet metal, that gets too hot to keep paint rusts, and after 46 years in the north west, most used one are also not usable.

[rodjr]

Yes, i am most concerned about finding a rebuild-able seat. Hopefully i can find a truck getting parted out, i would gladly pay freight for a correct seat and sliders.

On the heat riser, what i REALLY need is a good pic and a few dimensions, i work as a purchaser in a small sheet metal shop and have access to a brand new fiber laser as well as cnc press brakes so i can make that sucker (out of stainless), just want it close enough to look like it might have been original.

 

I am sure the clutch and run on are just time spent dialing it in. I do hope i can find a decent stock air cleaner assembly soon.

[datzenmike]

You want this heat shield...

 

[wayno]

The run on is easy to fix, when you come to a stop, put it in gear, turn the key off and let out the clutch at the same time, before you know it you will not even notice doing it, I don't even know I do it myself anymore, it's automatic/done subconsciously.

 

Where is Camano Island WA?

[thisismatt]

Yes, i am most concerned about finding a rebuild-able seat. Hopefully i can find a truck getting parted out, i would gladly pay freight for a correct seat and sliders.
On the heat riser, what i REALLY need is a good pic and a few dimensions, i work as a purchaser in a small sheet metal shop and have access to a brand new fiber laser as well as cnc press brakes so i can make that sucker (out of stainless), just want it close enough to look like it might have been original.

I am sure the clutch and run on are just time spent dialing it in. I do hope i can find a decent stock air cleaner assembly soon.

What you should really make are the heater defrost ducts that connect to the underside of the dash. They are thin plastic and tend to break off at the mounting points.

[thisismatt]

Waiting on pics.


The key to finding 521 parts is patience. I've been waiting for the same part from two different people for a while now...the hold up? Like yourself...lack of pics.

Kidding. Welcome to Ratsun.

What part?

[rodjr]

You want this heat shield...

 

 

Thanks! that is very helpful, i can definitely get in the ballpark with that. If i get one done that looks good, i will make a couple extra.

Heat riser in the works soon, clutch, run on, and pics for Sunday afternoon.  

 

Killing it with the clutch works, but will drive me crazy, if it does not work the way it was designed to work i will never be happy with it. I am the guy who will spend time and money to find a correct thermal vacuum switch to make an egr work properly with a quadrajet because without the egr, you don't get proper vacuum to the metering rods at cruise. Call it o.c.d. if you want, but i like to make things "right" so to speak. 

 

I will take a look at the defrost ducts when i get time.

 

I have to say, i have participated in a few forums in the past, and have never gotten this kind of welcome, you guy's are alright!

[thisismatt]

Watch out, we can turn on you in an instant

[flatcat19]

What part?

Hahahaha....

Heater ducts for under the dash...because the mounting tabs have broken off.

Seriously.




Want to make something cool for 521 owners?
Parcel trays and glove box inserts. As well as defrost ducts.

[kelowg]

Welcome abroad. Ppl here really know their datsuns. Facebook page not so much. Pics posting here bit a pain,but with pics we r able to help out much easier. Parts,ebay but some thing r overprice(rare, not always truely rare)  but luck for u,ur on west coast. Parts all around. now u have datsun,you well see datsuns everywhere.

[datzenmike]

 A good going over, checking  idle speed and mixture, ignition timing, plug number, float lever should fix the run on.

 

 

Look behind your dip stick handle at the top edge of the block, just below the head. There's a flat rectangular boss with the engine size stamped on it. Should say.... L 16

[gene knight]

welcome to ratsun

[mikec4193]

Hey RodJr

 

Welcome to the crazy world of Datsun trucks...I had to sell mine last year as I could not wrap my head around the lack of aftermarket parts...I was use to old AD style trucks and Willys Jeeps too...then I jumped into the Datsun world after being away from them since the late late 1980's...I was in for a rude awakening with the lack of parts....patience I guess is the key.....

 

Sounds like you gotta handle on it tho...

 

MikeC

[rodjr]

Ok, got the run on sorted, idle too high. There is something going on with the cable or carb though, it likes to hold up a bit and i have to blip it to get a drop to proper idle. I will get it fully sorted soon, the upcoming holiday is sucking up alot of what would normally be free time.

Engine # matches tag on firewall. Only real dent, passenger rear corner.

 

Pics: