NM 521

[Oilspot]

Well I figure the temp guage looks flawless so I'm  hoping the contacts just needed to be cleaned up. Figured I'd repaint the needles while I was in there and just give the whole unit a good cleanup. Sanded the white paint off the green globe things for a brighter cluster.

 The damn glass fractured when I was snapping the faceplate back on.... Shit!!! Talk about feeling disappointed in myself!!!! Luckily a local glass shop says they can cut me a new piece, same thickness no problem. 

Really hoping the temp guage works now!!!!

[Charlie69]

That is a nice cluster.  I use clear silicone between the chrome metal ring and the glass.  I run a bead around the bevel on the glass side of the chrome ring before clipping the ring back on.  Clip the ring on right after running the bead of silicone.  Do not worry about ant silicone the squeezes out as it cleans up real easy after it has set up over night.

 

If you need clusters or cluster parts pm me as have many cluster and parts.

[Oilspot]

1 minute ago, Charlie69 said:

That is a nice cluster.  I use clear silicone between the chrome metal ring and the glass.  I run a bead around the bevel on the glass side of the chrome ring before clipping the ring back on.  Clip the ring on right after running the bead of silicone.  Do not worry about ant silicone the squeezes out as it cleans up real easy after it has set up over night.

 

If you need clusters or cluster parts pm me as have many cluster and parts.

Thank you! I wish I'd taken a before and after, it was pretty dingy looking when I started. I like the silicone idea! Here in southern NM, if it doesn't have dust in it.... It just got here!!! 

I'm glad to know you've got "parts clusters". If the temp guage didn't come back to life I'll be on the hunt for one! I can't image driving the truck around without one.

[Charlie69]

I am having my brother Garret make some gaskets for between the metal and the plastic.  As soon as he gets these made I will post them for sale in the classifieds.  He will make them as close to original as possible.

 

By the way if you have to take you cluster apart again after using silicone the glass and the metal ring will stay together. Just pry the top clips off gently.

Edited September 10, 2021 by Charlie69

[mainer311]

Hmmm, I think you’ve inspired me to clean mine too. The inside of the glass is getting dirty.

[Oilspot]

1 minute ago, mainer311 said:

Hmmm, I think you’ve inspired me to clean mine too. The inside of the glass is getting dirty.

Be careful with the glass 🤣

I quick painted one of the wheels you hooked me up with and mounted a worn out tire to help figure out what size tire/ whitewall width I wanna run. 

Thank you again!!!!! Those modulars we're bummin' me out!!!

[Charlie69]

The closet size to the original bias ply tire is 195 /75 R14.

[datzenmike]

On 9/4/2021 at 8:34 PM, Oilspot said:

Best way to test the temp guage itself???

 It seems to be in great condition. Continuity in the board checks out. 

And if it is bad, does anybody have a good unit up for sale?

 

1 hour ago, Oilspot said:

 

Well I figure the temp guage looks flawless so I'm  hoping the contacts just needed to be cleaned up. 

 

You said there was power at the sender and grounding it did not cause a full deflection to HOT. If there is power, then there is continuity through the gauge. Like I said perhaps the needle is just stuck. Move it with a Q-tip.

[Oilspot]

2 minutes ago, datzenmike said:

 

 

You said there was power at the sender and grounding it did not cause a full deflection to HOT. If there is power, then there is continuity through the gauge. Like I said perhaps the needle is just stuck. Move it with a Q-tip.

Now that there's no glass that'll be super easy to try!!!

The cluster/ circuit board checked out perfect as far as continuity. I'm thinking the connection between the board and guage had oxidized/ needed to be cleaned. Maybe.....???? Hopefully!!!!!

[thisismatt]

Put some Noalox or similar on those joints, same with the bulb housing contacts

[mklotz70]

in reference to the factory tires.....here's a pic of the height of a factory bias ply tire.
http://www.bluehandsinc.com/misc-pics.html

 

[datzenmike]

Should be a 6:00 X 14 from that era or 175/70R14 which is 23.5" (ish) tall. How do we not agree on this??? 

 

https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp

[Charlie69]

You're Canadian!  LOL

[420n620]

55 minutes ago, Charlie69 said:

You're Canadian!  LOL

 

[Oilspot]

3 hours ago, datzenmike said:

Should be a 6:00 X 14 from that era or 175/70R14 which is 23.5" (ish) tall. How do we not agree on this??? 

 

https://www.tirerack.com/tires/tiretech/45_conversionchart.jsp

I agree 100%

, off the numbers a 6.00x14 should measure out around 23.5", no doubt about it.

Just measured the bias ply 6.00x14 I pulled off the spare. 25.5" diameter! 

Go figure!?

[datzenmike]

Damn, I based some wider tires based on 23.5" . The 6:00 X 14 being 175/70R14 must be wrong.

 

205/70R14 is close to 25.5"

[Charlie69]

The 720 ST rims come from the Nissan factory with 205/75R14s on them.

[mklotz70]

Oilspot and I measured actual tires......your chart was made by someone.  The info I dug up supports the dimensions Oilspot and I have....ours are actually a bit small.  I found two sites that list the 6.00-14-8PR LT tires.  The 521 manual shows that the rears are the 8PR(8ply rating) and the fronts are only 6PR.  Both sites list their tires of this size at 680mm overall diameter......which is 26.77" (26 3/4").  Tire Rack's site shows the 6.00-14 from 1965-1970 converts to 175/65R14.  The line below that shows this size in previous years and gives different "current" sizes.  6" is only 152mm.....so the 175 listings are already wider, but at 70% sidewall height(times 2 plus the 14" rim only comes to 600mm....or 23.6").  A 175/80R14 would come in about 25", so maybe a 185/80R14 would be the closest....if they even make them.  

 

***I just created a page on my site with this info to make it easier to find/reference later.

http://www.bluehandsinc.com/misc-pics.html

 

Edited September 12, 2021 by mklotz70

[datzenmike]

  Seeing is believing Mike. Most of my  speedometer gear calculations were done by percentage not tire size.  But this does give one pause. Three inches difference is huge!!!

[Oilspot]

after spending hours tackling different areas of the truck that need attention, I return to the engine. Last time i ran it, it ran fairly well with a slight to moderate hesitation off idle. So i figure I'd tackle that since it's getting closer to being on the road. Well crap, now it won't run worth a shit. A little poking around and I figure out that the accelerator pump isn't spraying a little stream o' fuel down the barrel. Guessing something made it past the fuel filter. 

 

Carbs off, and coming at least partially apart. 

 

Here's a straight forward question. What's the overall view on these units? I see a lot of people are switching to a weber. Is that because the stock units are garbage, or are they just harder to fix/ tune/ etc? That was a common move on the air cooled vw's 20 or so years ago. Time showed that the weber (for a stock configuration) was a worse carb for the engine and that taking the time to work the bugs out of a stock carb was the best move. Turns out the designers of the OG units actually knew what they were doing. 

 

And if they are a worthwhile, well designed carb. Does anybody have any better documentation on how to tune/ adjust them? At this point the only info on this carb is the semi unclear exploded view that came with the rebuild kit. 

[datzenmike]

The stock Hitachi is an excellent carburetor and other than performance is better in every way than the Weber. Hell the Weber doesn't even fit! Most of the hype is from comparing apples to oranges with the apple being a worn out, dirty or badly adjuster Hitachi and the orange being a brand new Weber. The Hitachi is very complex compared to the Weber so more can go wrong.

 

Dirt is the most common problem with all carburetors. Then a worn out accelerator pump... there really isn't much to actually wear out inside a carburetor. Next is out of adjustment or previous owners messing with the settings or loosing parts re-building them.

[mainer311]

The original accelerator pump plunger in a stock Hitachi is made out of leather and lasts a long time.  The rebuilt kit comes with a Viton plunger which will last a while, but is inferior. Either way it doesn’t matter, since original parts can’t be found for it.

 

The check springs and balls get crudded up too, and new ones should be in the kit. Way back, I rebuilt my Hitachi and the only things that really needed replacing were the gaskets and the accelerator pump. The other 4 million parts were fine.

[datzenmike]

I gor 4 or 5 leather pumps at a Canby one year. Agree the leather is more compliant than the plastic. Heard years ago that the leather is made from kangaroo skin which is impervious to gasoline. This was in the early '60s so???

 

I've rebuilt many Hitachis and never needed a gasket. They all peeled right off and were reusable. 

 

The front bottom screw that holds the base to the actual body is hollow to send manifold vacuum to the power valve. Unfortunately it is the same size as the rear bottom screw and the can mistakenly be swapped. The power valve forces a rich condition under full throttle increasing performance.

[Oilspot]

31 minutes ago, datzenmike said:

The stock Hitachi is an excellent carburetor and other than performance is better in every way than the Weber. Hell the Weber doesn't even fit! Most of the hype is from comparing apples to oranges with the apple being a worn out, dirty or badly adjuster Hitachi and the orange being a brand new Weber. The Hitachi is very complex compared to the Weber so more can go wrong.

 

Dirt is the most common problem with all carburetors. Then a worn out accelerator pump... there really isn't much to actually wear out inside a carburetor. Next is out of adjustment or previous owners messing with the settings or loosing parts re-building them.

Thank you for confirming that I'm not working with a turd!!!!! It is a complex carb, that's for sure. Looking back on the rebuild, I'm wondering if I got the accelerator pump "sprayer" little u-turn arm cleared out completely, i'm thinking I didn't because the burst of fuel when activating the accelerator pump was okay, but far from spectacular! 

 

Is the "second" barrel a vacuum secondary with very little mechanical activation? It barely opens when I pull the throttle linkage. I noticed this after I pulled the carb. My brain was a little foggy trying to work on it this morning. The damn neighbors crackhead brother was at my door trying to "borrow" $5 around 11pm last night. Needless to say I didn't sleep very well. I went back to sleep this morning for a little bit. Not really sure If i'll get back to it this afternoon. Late summer heat wave and It was in the damn high 90's yesterday and supposed to be again today as well as all this week. 

 

Edited September 12, 2021 by Oilspot

[Charlie69]

Mike always love the wording you use to describe a Hitachi anchor!!!  LOL

 

The best words I can use in a sentence containing a Hitachi carburetors are expensive parts (providing you can find them) and frustration.

Edited September 12, 2021 by Charlie69