IH 200 Very Underpowered

[ih-200]

So... I have a 1974 IH 200 truck with a IH 304 V8 engine and a manual transmission. It starts and runs real good at idle, but when starting out in gear/shifting, its so underpowered and sometimes even tries to stall out. It has a Holley 2bbl carb and a points ignition. I've been told that this is the nature of the Holley 2bbl carb and that mine was ok and didnt require a rebuild. I was looking on SSS at some carburetors and am not real familiar with them, if I "upgrade" to a different two bbl carb, which one should I get, or which one is "best" that will fit without any or much modification? I don't want to spend a ton on it, or I'd just put in a bigger engine. Any other tips or advice is welcome. Thanks

[scoutboy74]

You may have developed a vacuum leak which is most problematic when the engine is under load. Suggest you connect a vacuum gauge to measure manifold vacuum. When was the last time this engine had a full tuneup? Spark plugs, plug wires, points and condenser (if so equipped) are all items that require periodic replacement. Has the ignition timing been checked recently? That's also something that needs adjustment whenever any other ignition components are replaced.
Carbs do require periodic maintenance, especially with exposure to ethanol blended fuels that our all seeing, all knowing, gummint in their infinite greed and stupidity have forced us to consume at sky high prices. There are several types of Holley carbs. You should attempt to ID which model you have. There are numbers on the front face of the airhorn. Post those up here and/or include some pics with your air filter housing removed. A Holley carb that has been thoroughly cleaned, kitted with quality service parts, and properly tuned is just as capable of delivering reliable performance as any other brand.

[Robert Bishop]

It is possible that your accelerator pump is out of adjustment, causing your off idle stumble. Also possible is that one of your main jets is partially obstructed from debris inside the float bowl or maybe your carburetor has had the wrong size main jets installed. These are just a few things (of many) to consider that could cause the symptoms you have.

Robert