Very bad fuel economy

[Mohamed Azmy]

In have Datsun b310 with A15 engine and I'm getting 11km/l only and that happened after rebuilding the engine and the carburettor then I changed the main jet to 90mm and 120mm and still getting the same result and I got new NGK spark plugs and I changed all electric parts to new ones if anyone can help that will be great 👍 

[datzenmike]

25.6 MPG (US gallon) is not that good. I would expect much closer to 30

 

 

Is the choke remaining on after the engine is warmed up??? Take the top off the air filter and look. The flap should be straight up and down when engine warm.

 

Has the ignition timing been checked? You'll have to find out what to set it at.

 

Have you set the valve clearances? You'll have to find out what to set it at.

[Mohamed Azmy]

The choke is disconnected and I checked if it opens it isn't, I don't know Valve clearance the mechanic did it twice and the same result, I will redo the ignition timing again but I don't think because of it 

[datzenmike]

You said the choke was checked and isn't open????

 

This is open...

 

 

This is closed...

 

 

 

The choke must be fully open.

 

Ignition timing is critical to get the most out of your engine power.

 

How you drive is also directly connected to fuel economy. Just remember that it takes fuel to move your vehicle so every time you use your brakes you lose the fuel used to get you up to that speed. Avoid braking as much as possible (this takes a lot of practice) by going slower and leaving space between you and the vehicle in front. Anticipate stops ahead and slow gradually. Try to avoid complete stops. Accelerate slower and take your time. Empty vehicle of anything not really needed when driving. ALL weight has to be accelerated up to speed using up more fuel. Avoid short trips when the engine is not fully warmed up but don't waste time warming the engine. As soon as you start it, start driving. Keep tires fully inflated to the recommended pressure. Low pressure tires use more fuel to turn than firm ones. If you are not, keep a mileage log. This will remind you of the above tips and encourage economical driving. Anyone can gain 10% better economy by doing the above.

[Mohamed Azmy]

I mean that is open 🤣 🤣 

 

I don't think that the problem with way of driving as before doing the all the work it was making at least 14 km/L so I will check the Ignition timing again and try it