I have owned my 67 250s for about 6 months now and drove it from Michigan to South Carolina and until recently have had no problems with the carbs besides making normal adjustments every few months. Recently, i was out driving one afternoon and the carbs started acting up....wanted to stall when accellerating from a stand still, was eractic a cruising speed and was backfireing. I couldnt go above 55-60mph, i normal can cruise at around 75 just fine. My mechanic took a look and replaced rotar,cap, and wires and check all plugs and came to the conclusion it was an air leak. He wants me to do a 1500 weber conversion, does this sound right? I think its an air leak as well, as when i place my hand over the front carb the engine shows no change. Is there an easier less expensive fix...i thought maybe changing the gaskets, any ideas?? Thanks.

 

Get a new mechanic. Then rebuild the carb and re-install with new gaskets.

 

Is there any other common places besides the gasket that would cause a leak? Also, do you know of any place i could send the carb out to be rebuilt? Im in the air force and im stationed in rural south carolina....to say the least, there isnt much to choose from for mechanics that i would trust to rebuild...my current mechanic didnt want anything to do with them and "the only person he knew who had luck redoing the zenith mercedes carbs died 10 years ago" haha, thanks

 

You have a few options with your classic car, and the type of repair you do isup to you and depends on your plans for the car. There is certainly nothing wrong with webers; they are straight foward in design,very good carburetors, andalot of people in the US and Europeknow how to tune them.

If you are looking for an originalrestoration, I bet RBM of Atlanta could get your authentic carb identical to the one on the vehicle OR an exact overhaul kit that would snap on without a single modification. Authentic parts are pricey, but they fit together so well,and work so well, that I have never regretted buying an authentic part.

Honestly, it is difficult to find the "one" single component failure on a car when everything is old. Some parts fail intermittantly, and only act up when cold or under acceleration etc. Of course you have to check all the simple things like hoses and gaskets first before you begin replacing major components. But if the repair begins to go into overtime, you may find yourself, like me and others, replacing a few things, due to a wrong guess, process of elimination, or for peace of mind, just to get itback on the road quickly.Sometimes it is as simple a split hose or a pinched wire and that would be great.

What is the condition of the engine compartment? Is it clean, or does it look very old and corroded? If it is in need of restoration, I wouldnt replace the hoses one at a time everytime one blows, but rather get rid of "ALL" the stiff cracked old hoses before they cause any more problems, then maybe you can have a sense of reliabilty, instead of waiting on the next hose to blow.

In my personal experience, if the carb looks oldbeat and corrodedon the outside, the inside is probably no better. Old school mechanics would spray starter fluid on suspect leak points to find leaks. If there was no leak, the fluid would just evaporate. If there WAS aleak at the point of spray, it would be sucked into the engine by intake vacuum and cause the engine to rev up. It was a quick way to find a leak without disassembling anything. Ithowever it could be very dangerous if the fluidignited.

In my personal experience, heres what goes wrong with carbs:

Air leak, air leak, air leak, wipes out the entire fuel/air ratio. A broken gasket, a loose hose, or a hose merely split at the clamp, broken actuators, missing rubber caps, or worn throttle bushings, will make the car run badly.

RUST: The inside of the fuel tank can rust and clog the tank screen, fuel filter, jam or tear fuel pumps, rust float assembly, clog lines or thescreen in the carb, or the jets themselvescausing fuel starvation or poor spray pattern.

Aluminum corrosion and more white oxidation inside the carb body, clogs or corrodesfuel openings which need to be precise, can cause fuel leaks, fuel odor,engine fire,improper fuel mix, or general bad performance. This is why if the carb looks bad, it is very tempting to just replace the dumb thing.