How do you know your 308's carbs are out-of-tune?

I'd suspect plugs first, bro......

The low miles "around town" tends to let them accumulate fouling deposits.

Try a few high speed blasts and see if it improves any......maybe with some fuel cleaner, then change to fresh plugs.

290 out to Chappell Hill, south thru Racoon Bend, west past Bluebonnet Farms to Bellville and stop in Cat Springs for dinner!

 

Always do carbs last. Electrical first: plugs, wires, timing. Make sure the coil (s) are still strong; they do wear out over time. If all that checks out, then you look at the carbs. Rebuilt and tuned Webers should last longer than a year, although OLD Webers may be developing wear in the shafts or something causing air leaks.

Ken

 

hey greg. where did you get your carbs done, and how much did it cost? was thinking about getting my done. I tried adjusting the idle myself and probably did more harm than good, so I thought I'd have a professional do it, or at least someone who knows what they're doing it.

 

Rick, mine were WAY off when I first got the car as they had not noticed a manifold leak!

I'd trust Pinnacle Motorsports, or Vintage to do it here in town........

 

Gotta agree with Bubba here. See if running your car at high revs for a few miles burn off any carbon deposits on your plugs. These engines like high RPMs. Check your mixture and those other things Ken mentioned. As you mentioned, your synchronized Webers should stay that way for a long time.

Barry

 

Trust Barry!!!!.......he's a doctor you know.........

 

I still rely on you guys, Tex, to keep my car right. That's why there are different "specialties" out there.

I learned a lot from one of my techs after my major service last year. I asked him to take the car out on the "proving circuit" we have out here near Classic Coach. He has an early '78 carbed GTS. He really checked the car out. When we got back to the shop, he switched the car off and it made that little "thump" back there somewhere. Then he said, "try to drive it that way frequently." Good advice.

 

When you get your mechanic to tune them up properly then index your gas mileage by driving 100 miles the same way. You'd then be able to tell if your mileage goes way down if your carbs are out of tune. Seriously, other posts have address the carbs going out of tune issue and the main concensus is don't play with the carb settings (without an LM-1 air/fuel mixture setting tool) or expert experience mechanic since they rarely go out of tune without wear of the jets or linkage or gasket leaks.

 

It's good advice, Greg. I followed that bit of advice my tech gave me a year and a half ago. The car needs to be driven that way. So, listen to Bubba and drive it as it was designed to be driven.

Barry

 

I had the same issue about a year ago. When I would shut the engine off, there was always a backfire. I paid a mechanic for three hours of time to sync the carbs. After that, the backfire went away and the acceleration was awesome!

 

The only reason that Webers should go 'off-tune' is wear in the various metal bits that make up a Weber, e.g. throttle shaft wear, butterfly plate contact point, fit, etc. This wil not happen in 1700 miles or one year. Something else is going on.

 

Trust Big Tex!!!!.......he's Bubba you know.........

 

*blushing*

No, you forget I came into the game as a DRIVER.......if you can't fix it with MORE THROTTLE or a fire extinguisher, I'm pretty much clueless!

ROTFLMAO!

Merry Christmas, Dr. Barry......Accounting has learned I failed to take the alloted Vacation Days, and are leading me towards the front door now.....

I tried to tell them to put the money in a paper sack......

For all the "bad press" the carb cars get, I'll take that over a darn computer any day, computers RARELY work any better, when I hit them with a wrench!

 

And a very Merry Christmas and a Happy and Healthy New Year to you, Bubba.

...and to you all!

Barry

 

I don't think so, Bubba.

Anyway, I'm glad that all has worked out well with Greg's engine "problems." These cars are just not happy at low RPMs.

Bubba, have you had the chance to drive a fiberglass GTB?

 

Heck, I don't drive my STEEL ones anymore! We stacked them out back with the old broken appliances........

I don't know of any glass examples here in Houston, and I'm afraid my kart racing manuvers have MADE my reputation around here!

Do you think the difference is noticable, from the 'seat of the pants'??? I have long heard of the "300#"s of weight difference.......but I've long suspected that was strictly derived from dialing in the cams to Euro Version advance specifications....

And you know Valeria and I can make up that 300#s EASY against some other owners here!

 

I'm not sure of the total weight saving, Bubba. I have the OEM thermal reactor muffler sitting in my garage. I must weigh about 130 pounds. The ANSA on my car now weighs about 35 pounds. I've heard the fiberglass body saves about 200 pounds. So that's about 295 pounds right there. As you mentioned, these early GTBs have the Euro cams. My car has the US bumpers and a full sized spare tire. The two ar pumps are still there, but offline.

I never drove a steel GTB, but have driven GTSs, both carbed and QVs, and yes, there is a noticeable "seat of the pants" difference. Even one of my techs, who owns a carbed GTS, noticed the difference. I'm sure it's due to both the weight savings and the cams.

Barry