alright, I'm going with the 4k carb+ rebuild.

yeah i am going get 4k jets and a rebuild kit for it from cheapa auto spares.

Opps should have read the post better first I'm refering to the 3k carby's mech secondrys and flapper valve and not the 4k carbys as they are totally different beasts

 

If you have a good parts guy in Toyota, He should be able to track down jets from Japan.

You will end up paying about $12 per jet.

Drilling them out is a tricky job, quite often you will go from too lean, to too rich with the twist of a drill.

We are running 114 in a primary Venturi of 21mm and 181 in a secondry venturi of 25mm, If you can source a 3k with 25mm secondry venturis grap it.

The most common sec venturi is 24mm if you get one of those Jet secondry to 177.

These jet sizes are only ball park figures from my testing.

 

Becarful changing jets you don't miss the washer that goes under the jet. Miss that and you will have all sorts of mixture problems

 

Be careful when rebuilding carby there are two steel balls that have a habit of disappearing, One lives under the discharge weight of the accelerator pump circuit, the other lives under the spring of the accelerator pump, there different sizes so don't mix them up. If missed they can cause mixture problems as the air rushing through the venturi has a habit of sucking fuel out of the accelerator pump discharge nossel,( Noting most 3k carbs will do this miss the balls and it will be worse.)

 

Other things that may trip you up is the screws that connect the throttle body to the main body, one screw has a hole in it this acts as a vacume passage and needs to be installed in the hole closest to the float chamber.

 

Also beware some 3kc engines had a carby with a 19mm primary they are great for around town as offer a bit more down low, but are a piece of rubbish when expected to perform in the upper rev range.

 

Cheers

Andy

Edited March 13, 201115 yr by Andy43