Hello Folks, I'm new to the Mazda Forum, I have a 1992 B2200 extended Cab, manual tranny, with an aftermarket Weber carb. I purchased this about 6 weeks ago from the original owner, it has 28,000 original miles on it!!!.Overall it is in very nice condition and I plan/hope to keep it in nice shape. My questions to you folks are:
Before I do my first tune up on this, are there recommend brands for plugs, condenser, etc? Any particular brands to stay away from? How about oil brands and filters? Any recommended preventive maintenance that should be done more often than recommended in the manual?
Finally, I get 22mpg with almost exclusive 55 mph driving, and suggestions as to how to increase millage? Thanks in advance, Ed

 

Carbureted! Wow!
better mileage = different jets, smaller of course. May get hesitation as a result. Some tweaking to accelerator pump circuit maybe?

Quote i found: "
One of the things I do is change the main jets on the carb. I go down at least one size. This works due to fuel being thinner today. Smaller jets restrict the fuel flow. Be sure to check the spark plugs for a too lean mixture. Don't just change the jets and not check as this can lead to a hole in a piston."

AND: Contrary to popular belief, the main jets are designed to control the air/fuel ratio of the cruise circuit, not wide open throttle. This covers an RPM range from around 2000 – 2500 and up, starting up as the transfer slot begins to fade out. Again, test in steady state by holding a steady throttle position. Record the air/fuel ratio in 500 RPM increments starting at 2000 RPM, and work upward until you feel comfortable. Shoot for an air/fuel ratio of 14.7:1 (lambda 1.00) by changing main jets. Leaning the engine out further increases NOx emissions and temperatures, without producing much better results. At WOT, shoot for an air/fuel ratio of around 12.5:1 (lambda .85) for naturally aspirated engines.

Accelerator Pump

Now that we have tuned in the idle, transfer slot, main jets, PVCRs, and power valve, we can focus our attention on transient fueling. On double-pumper carbs, the secondary linkage should be disconnected again, while the primary accelerator pump is tuned by changing pump cam position, pump cam, and squirter size. Target a transient air/fuel ratio that is slightly richer than your current target air/fuel ratio. For part throttle, this might be around 13.8:1 (lambda .94). At full throttle, try to maintain your target WOT ratio of 12.5:1 (lambda .85) without any momentary lean spikes. With the primary pump now tuned, hook up the secondaries and repeat the procedure for the back.

Most from: Carb Tuning Tips: Improving Mileage, Performance, And Drivability | Chevy Hardcore

For weber specific carburetors, type the following as a web search: weber carburetor tuning.

Interesting Video:


I had a very similar vehicle: 1987 Nissan P/u, 2 spark plugs per cylinder!? It holds lots of speakers, especially when you remove back seats! 142 Db on the meter 20 years ago! I had 2 different set-ups. The 6x9's with the 12" subs were both Cerwin Vega!

 

Ok, good information, how about brands of plugs and tune up parts to stay away from? or Brands that you do recommend?

 

Nice truck and good advise buy Noggin.
You do know that the Mazda Pick-up trucks are identical with the Ford Ranger. Tehre is a good forum for the Ford Ranger: the rangerstation.

As far as parts go try to stay as close to original as you can. Avoid funky stuff like splitfire and E3. NGK makes the Mastercraft plugs. Keep in mind you get the best spark from copper, but they don't last. You get the longest lasting plugs with platinum but the spark is relatively weak and you get a happy medium with iridium, good spark good durability but high price. For wires I use BWD.

When buying parts stay away from the cheapest stuff. It's cheap for a reason and costs you more in the long run. Unfortunately it is not as simple as mentioning a particular brand. With each item some research is required.

I am not 100% sure if your particular engine is the Ford Lima engine. If it is the Lima and has 2 plugs per cylinder then you can do the following: from factory the second plug fires into the exhaust stroke. By rerouting the wires you can make it a true double ignition with both plugs firing at the same time. It is explained in the ranger station somewhere. This guy reported an improvement in fuel consumption, torque and power.
Avoid ethanol blended fuels.

 

WRONG - This is true for USA Mazda trucks 1994 and newer.

1993 and earlier Mazda trucks are Japanese made.

I've driven essentially that same truck (1988 B2200 Cab Plus 5-speed with Weber) for 19.5 years now. Mine has AC and I added aftermarket cruise control in 2003 and an aftermarket tach about 8 years ago.

Tune up is change oil and filters. Gear oil and differential oil like every 40 to 50K miles. I use NGK spark plugs, still have original spark wires, alternator, etc. I use Valvoline motor oil.

When you each high mileage, ignition switch electricals and clutch hydraulics will become weak spots. If you ever develop a cooling system leak or hotter running, don't ignore, as overheating can cause head gasket issues. At about 150K miles smoke typically becomes visible, bad oil control ring, so try to change oil every 3K miles.

Nice truck. More traffic and technical on Mazdatrucking.com and on MazdaBScene.com, and I go there more.