carb problems

[68bay]

ive got a 1600 twin port engine in my van

what i want to now is whats the diffrence between a 34 pict 3 and 31 pict 3 as i thought my van is supposed to have a 34 pict 3 but i have a 31 pict 3 can i use this instead

thanks steve

 

[bac2ba6]

You can use SOME 30PICT/1 carburettors on a 1600cc engine. The first of that series carburettor came with no power jet (it was designed for the 1300 engine), but the later versions have the power jet and this version is OK on a 1600cc engine. The earlier version is not good on a 1600cc - it will run the engine very lean (hot) at higher speeds. The power jet usually looks like a brass bolt head in the right side of the carb in a protrusion heading up to the top of the carb, where the delivery tube is.

The 31PICT/3 can be used on a 1600 and the main difference is the jet and throat size so you may have to run it a bit richer as you dont want to run it too lean as this will cook your engine you can buy bigger main jets for them for around £4 odd

The 34PICT/3 carburettors have a larger 26mm venturi, which allows the 1600cc dual-port engine to breath better for increased horsepower. These carburettors have more complex fuel metering which allows the carburettor to run a little leaner for emissions reasons. These leaner settings also make the engine harder to tune as it ages (the VW engine really likes to run a little rich), and so sometimes changes to the fuel jets are needed. Two replacement 34PICT/3 carburettors that are available the Bocar and the Pierburg. The new Bocar carburettors almost always have very lean jetting which may need alteration.

Personally if you can get one i would for the 34PICT/3

hope thats enough info