This is one of the questions I got via email: what is the difference between the Hitchcock set and just replacing the TB with a carb. I had some idea but double checked with AI. Now Gemini (goolge AI) produced 100% nonsense. I knew enough to see that immediately. However Opus 4.7 was spot on which I find refreshing because this is such a niche theme. here is what it had to say:
This is a really interesting question that gets to the heart of why the Hitchcocks kit exists. Here's the key distinction:
The BS4 Himalayan is fuel injected — it doesn't have a carburettor at all
The 2018–2021 (Euro 4 / BS4) Himalayan uses an Electronic Fuel Injection (EFI) system with a throttle body, not a carburettor. The "throttle body" is simply the air-metering component of that EFI system — it contains no jets, no needle, no float bowl, and relies entirely on the ECU and injector to deliver fuel.
Simply bolting on a carb in place of the throttle body won't work
The standard ignition timing on the BS4 Himalayan is managed by the ECU, which reads inputs from sensors including the Throttle Position Sensor (TPS). If you just swapped the throttle body for a regular carburettor, the ECU would lose its TPS signal and the ignition system would either not function correctly or not run at all.
What the Hitchcocks kit actually does
The Hitchcocks carburettor conversion kit includes all the components required to convert the 411 Himalayan away from fuel injection to a CV (Constant Velocity) carburettor, delivering similar performance to the stock EFI system but with the benefit of simplicity and the ability to fine-tune jetting yourself to suit the engine or any future modifications.
The critical difference, as noted by owners who've researched it, is that you do NOT get a standard OEM carb — you get one with an adapted TPS (Throttle Position Sensor) built in. This is needed to keep working with the ECU-governed ignition system. The carb in the kit has been specifically modified so it still sends a valid TPS signal to the ECU to keep the ignition timing functioning correctly.
All components are bolt-on items and the modification is completely reversible. The kit comes jetted to suit the standard 411 Himalayan, with a 125 main jet and 20 pilot jet for a stock bike, and alternative jets are available.
It only fits the 2018–2021 fuel injection models where the standard ECU is located under the seat.
In summary: A plain throttle body swap for a carb would leave your ignition system blind and the bike either running very badly or not at all. The Hitchcocks kit solves this by supplying a carb pre-fitted with a TPS, making it a genuine plug-and-play conversion rather than a bodge.
This is a really interesting question that gets to the heart of why the Hitchcocks kit exists. Here's the key distinction:
The BS4 Himalayan is fuel injected — it doesn't have a carburettor at all
The 2018–2021 (Euro 4 / BS4) Himalayan uses an Electronic Fuel Injection (EFI) system with a throttle body, not a carburettor. The "throttle body" is simply the air-metering component of that EFI system — it contains no jets, no needle, no float bowl, and relies entirely on the ECU and injector to deliver fuel.
Simply bolting on a carb in place of the throttle body won't work
The standard ignition timing on the BS4 Himalayan is managed by the ECU, which reads inputs from sensors including the Throttle Position Sensor (TPS). If you just swapped the throttle body for a regular carburettor, the ECU would lose its TPS signal and the ignition system would either not function correctly or not run at all.
What the Hitchcocks kit actually does
The Hitchcocks carburettor conversion kit includes all the components required to convert the 411 Himalayan away from fuel injection to a CV (Constant Velocity) carburettor, delivering similar performance to the stock EFI system but with the benefit of simplicity and the ability to fine-tune jetting yourself to suit the engine or any future modifications.
The critical difference, as noted by owners who've researched it, is that you do NOT get a standard OEM carb — you get one with an adapted TPS (Throttle Position Sensor) built in. This is needed to keep working with the ECU-governed ignition system. The carb in the kit has been specifically modified so it still sends a valid TPS signal to the ECU to keep the ignition timing functioning correctly.
All components are bolt-on items and the modification is completely reversible. The kit comes jetted to suit the standard 411 Himalayan, with a 125 main jet and 20 pilot jet for a stock bike, and alternative jets are available.
It only fits the 2018–2021 fuel injection models where the standard ECU is located under the seat.
In summary: A plain throttle body swap for a carb would leave your ignition system blind and the bike either running very badly or not at all. The Hitchcocks kit solves this by supplying a carb pre-fitted with a TPS, making it a genuine plug-and-play conversion rather than a bodge.