spark plugs, wires, and coil. failed smog

[Chance]

so I just failed smog she's running real rich. never thought to check plugs since I bought it but the plugs are fouled out black and previous owner was using cheap autolite plugs. so I wanted to see if y'all knew part numbers for ngk or ngk iridium plugs and wires, maybe a good distributor cap. I know Mike doesn't like messing around with new coils since most are Chinese trash but it doesn't feel right replacing everything and not that so is there a good coil I can replace it with? also never tuned a carb before so if y'all could help out on that so I can get this thing from running so rich it would be much appreciated, its got a weber on there right now. 

[datzenmike]

Where's the ground strap on the plug in the picture?????? Looks like it broke off in the cylinder!!!! Miss firing plug with throw the HC levels through the roof.

 

Forget Iridium plugs this ain't no Corvette. Get NGK B6ES for the '73 gap 0.028"-0.031"

 

If the engine runs, then the coil is WORKING!!!!

 

 

Running rich is most likely the choke is not shutting off. When warm, take the top off the air filter and look. The choke flap should be fully vertical not closed or horizontal. Is it????

 

With engine running look at sight glass on front of carburetor. Is the fuel level at the half way mark????? Yes???

 

 

 

 

The idle speed CO and HC can be adjusted but no sense if the choke is the cause.

[banzai510(hainz)]

Mike the ground strap part might be on there. just a optical Illusion. If there is no strap its a Outbourd 2 stroke plug.

 

autolite plugs are not bad just the tread pitch is just not exactly right. They seem to get stuck in there trying to pull them out later.

use NGK or NipponDenso

 

Re[laceing the plugs and points and setting them correctly will help. Swapping coils that were working I really dont think is going to help.

 

Having a Mech that can dial this in with yu will be best if you can adjust the carb and timing while watching the emission meter to get it to pass

 

where do you live to still have to go thru emissions?

[Chance]

the ground strap is there just the angle of the picture, optical illusion like Hainz said haha. ill take a look at the choke and report back, Mike what if I wanna treat the ol' Datsun to some iridiums haha. Hainz I live in Nevada 

[banzai510(hainz)]

Emissions in Nevada??????????????Your kidding Me?  Beside Las Vegas does anybody really live there.

 

Just buy the cheap NGK copper plugs

 

Hope they are using 1973 emssion standards not 2024

Edited June 29 by banzai510(hainz)

[Chance]

Vegas is a dump haha and the limits seem 2024ish, car needs to be a '68 or older to be exempt which is crazy 

[Chance]

she's wide open, but there's a leak on the carb (see picture) on the right  what is this? also im not seeing any sight glass on this carb mike

Edited June 29 by Chance

[datzenmike]

38 minutes ago, Chance said:

the ground strap is there just the angle of the picture, optical illusion like Hainz said haha. ill take a look at the choke and report back, Mike what if I wanna treat the ol' Datsun to some iridiums haha. Hainz I live in Nevada 

 

You are wasting your time with iridium plugs, more so, you are wasting your money. It won't run one bit different.

 

 

4 hours ago, Chance said:

 

Well point it out. Because I see nothing.

temp-Image-O91-Wad.avif

[datzenmike]

4 minutes ago, Chance said:

she's wide open, but there's a leak on the carb (see picture) on the right  what is this? also im not seeing any sight glass on this carb mike

 

Well naturally you don't have a stock carburetor. He helps to mention these things. I don't 'do' Webers never worked on them so hope that it's the shitty plugs that were in it.

[Chance]

here's another pic mike of the plug.

[datzenmike]

There it is!!!

 

Spark plugs are self cleaning but they have widely different heat ranges. If too cold deposits will not burn odd. Get the correct NGK with a 6 heat range.

[Chance]

2 minutes ago, datzenmike said:

 

Well naturally you don't have a stock carburetor. He helps to mention these things. I don't 'do' Webers never worked on them so hope that it's the shitty plugs that were in it.

well I dontt think 620's came with a weber stock on them.

[datzenmike]

That's right so worth mentioning here.

[Chance]

8 minutes ago, datzenmike said:

That's right so worth mentioning here.

I did at the end of my original post

[datzenmike]

Pardon me!

[EDM620]

I think you might have referred to the baling wire wrapped from the hose clamp to carb body. That indicates to me that the fuel hose is too large ID (Inside Diameter) to properly fit the fuel inlet barb on the carb. An attempt to make a seal that way is basically unsafe. Undo the hose clamp and see if the fit is loose. Look for a reason - hose stretched? Hose barb damaged? Hose clamp itself NFG? Non-fuel rated hose used? You might need to get a new length of proper sized fuel hose and new clamps to solve that.

[Chance]

4 hours ago, EDM620 said:

I think you might have referred to the baling wire wrapped from the hose clamp to carb body. That indicates to me that the fuel hose is too large ID (Inside Diameter) to properly fit the fuel inlet barb on the carb. An attempt to make a seal that way is basically unsafe. Undo the hose clamp and see if the fit is loose. Look for a reason - hose stretched? Hose barb damaged? Hose clamp itself NFG? Non-fuel rated hose used? You might need to get a new length of proper sized fuel hose and new clamps to solve that.

was wondering why it was there as well I'll check it out. accelerator pump is leaking so I think im just gonna rebuild it, who knows how long its been in there. 

[datzenmike]

There's not much to wear out on a carburetor, all it does is mix air and gas, accelerator pumps mostly get all the wear. Gaskets if taken care of can usually be re-used. Most often the adjustments have been messed with and need to be set back to stock. Dirt or deposits clogging jets are a big cause of it not running properly.

[Chance]

3 hours ago, datzenmike said:

There's not much to wear out on a carburetor, all it does is mix air and gas, accelerator pumps mostly get all the wear. Gaskets if taken care of can usually be re-used. Most often the adjustments have been messed with and need to be set back to stock. Dirt or deposits clogging jets are a big cause of it not running properly.

the redline kit is only about $30, so just for the piece of mind on the long trip I'm gonna give it a refresh. but I agree I think the adjustments are off and that's whats causing the real rich running. 

[banzai510(hainz)]

are these emission on a drive wheel as one is driving or just at idle with a tester in the exhaust.

 

I go to a resonable mechanic and play with the idle mixture and timing of the dist to get this to pass.

I had 44mm Mikunis and they passed using 1969 emissions specs(lucky this was very short lived in Washington)

 

If truck running fine just lean it out then turn the carb back to best running.  Yes your plugs are black but not worring where I would panic

Edited June 30 by banzai510(hainz)

[MachineMan]

6 minutes ago, banzai510(hainz) said:

are these emission on a drive wheel as one is driving or just at idle with a tester in the exhaust.

 

I go to a resonable mechanic and play with the idle mixture and timing of the dist to get this to pass.

I had 44mm Mikunis and they passed using 1969 emissions specs(lucky this was very short lived in Washington)

 

If truck running fine just lean it out then turn the carb back to best running.  Yes your plugs are black but not worring where I would panic

 Both idle and the in ground roller.

 

I'm in California and always have had older cars.

If your car is running well what we would do was make an appointment.

Install fresh spark plugs, get up on the freeway and do some driving.

Show up on on time and let them do their thing, usually no problem.

 

Old cars with old carburetors can have issues with wear at the butterfly shaft.

I have seen, and had to make replacements for, bushing that were so "oval" air was rushing in.

When there are no bushings, just the carb body it's self, life gets complicated.

But I have repaired that headache more than once.

Most recently a 1978 Toyota forklift with bushings that were ovaled and bell mouthed beyond belief.

 

A little over 24 working hours to remove it, rebuild it complete, including making replacement parts,

plus modding it to make it more simple, then install it and adjust it.

The rebuild kit was very hard to find, and cost $94.00

My invoice to them, was a favor and a gift at $1,200.  

[datzenmike]

9 hours ago, Chance said:

the redline kit is only about $30, so just for the piece of mind on the long trip I'm gonna give it a refresh. but I agree I think the adjustments are off and that's whats causing the real rich running. 

 

Also make sure on a carbureted vehicle that the engine is fully warmed up all the way.

[RLJ]

I thought they stopped sniffer tests on the roller in California. 

[MachineMan]

1 hour ago, RLJ said:

I thought they stopped sniffer tests on the roller in California. 

 

I think they still do it on older cars, the ones that don't have the fancy plug under the hood.

[datzenmike]

Isn't that how VW got their diesels to pass emissions? There is no emissions test, the test is to ask the vehicle if the emissions system is working. The emissions systems tells the tester all's well. For VW the test mode was rigged to answer good.