I often get choke operation questions, so here is a video to help all SU carb newcomers. I made this video because people sometime have trouble starting their Bugeye, especially when it’s cold. Proper choke operation is crucial, otherwise it’s easy to drain your battery before the car will start.
When pulling the choke on an SU carb equipped car, it’s important to pull it out far enough to enrich the mixture. The first inch or so of travel is for high idle and the second inch or so lowers the jets to enriched the mixture. Pull too hard you’ll break the mechanism. Don’t pull enough and you won’t enrich the mixture sufficiently for cold start. Thus I propose you have a helper pull the choke while you watch, and learn the way your particular choke assembly operates. Each one is a bit different and once you are familiar, it’s quite simple.
Once your car starts, leave the choke out too long and you’ll hear the engine sound lumpy with a “whop, whop, whop” sound that means you are over-rich, and it’s time to ease the choke back in. In fact, you want to get the choke off as soon as possible.
Mechanical fuel pumps complicate this process and unless you are building a concours car, we recommend an electrical pump kit (see below). The original pumps had a priming lever so you could manually prime your carbs after your Bugeye sat for a while. New mechanical pumps don’t have that primer, so you can crank seemingly endlessly to develop a prime on a cold morning, especially if the car sat for more than a week. The electrical pump immediately primes your carbs so you can start a cold Bugeye much faster, even if your battery is less than 100%.
The other big issue with mechanical pumps has to do with diaphragm failure, which we often see, which can result in fuel pouring out of the pump not too far from a hot exhaust. Moreover, mechanical pump failure can lead to filling your sump with fuel, and trashing your oil and bearings, since the pump is block mounted. And they can also allow engine oil to leak too if the gasket is no good.
Our fuel pump kit eliminates these ills, and has everything you need to mount the pump and go electric. We use a solid state pump without points and have never had one fail on the cars we prepare. We recommend mounting it at the back of the car on the passenger side bulkhead. This puts the pump out of the way and close to the tank.
To do this, we use a threaded insert that allows you to secure the pump to this hollow cavity. You simply drill two holes and fill them with the threaded inserts we provide. You then screw in the rubber buffers in our kit, and mount the pump on the rubber mounts. This quiets the pump and isolates any vibration. You then splice into your fuel line with the two short lengths of rubber hose and clamps.
Under the hood, you remove your fuel pump from the block and affix the blanking plate (included) to seal up the sump of your engine. You can then cut the fitting off the fuel line and attach a rubber line from your metal fuel line directly to the carburetor. We run switched power to the fuel pump so it comes on with the key. Our pump works with positive or negative ground.
To install the Rivet Nuts with this kit you will need a Rivet Nut Tool, you can get one included with your kit by selecting it in the drop down before ordering.