Running Rich, Fuel Injection to Carburators Options

[BENBRO02]

I finally got my 914 on the road but switched to carbs to save money. The car runs rich. I have heard that the stock cam is not the perfect profile for carbs and also that the car needs to be run slightly rich to keep the engine temperature down. I have never adjusted a carb before and was wondering if I should try to lean the mixture myself or if this is better left to an expert. I recall that if an engine runs lean bad things can happen to pistons and valves.

[McMark]

The cam will work fine, but is pretty mild. So a different cam, in the same engine, would make more power. But the stock cam is not a problem.

You need the following to find success:
1. A GOOD linkage (CSP Bellcrank Linkage). None of the cross-bar linkages are good.
2. All four throats must be synchronized correctly, both at idle and off-idle.
3. The venturi must be sized correctly which depends on which carbs you have and the size of the engine.
4. The idle/main/air jets must all be sized correctly.
5. The floats must be set correctly.
6. The accelerator pumps must have matching delivery rates.
7. The ignition timing must be correct (123Ignition Bluetooth Tunable Distributor).

If your mechanic doesn't talk about ALL of these things, he may not be the right person for the job. Correctly tuned, the carbs should give nice smooth engine performance. I see a lot of carb engines come through my door, and a lot of those were worked on by other shops that didn't really know what they were doing.

Carbs are becoming a bit of a lost art for mechanics. I've spent an absurd about of time learning and understanding how they work and how to tune them. Any 'normal' repair shop isn't going to invest that kind of time for a small percentage of their customers.

The ideal answer is to learn how to do things yourself -- at least the basics. Carbs take pretty regular tweaking and tuning. They're NOT set it up once and you're done. So you either need a shop that knows what they're doing, or you need to start learning.

I cover a few aspects in this video.

https://www.youtube.com/watch?v=ZS3oNSwkUPk