Originally Posted by
geezer101
There are 2 main problems with the Mikuni carb - their CFM restriction and the anti pollution mechanisms. The Mikuni is a complicated carb to perform a full rebuild on if you are stripping it down to every last 'O' ring and seal. I have found that most rebuild kits need to be custom trimmed by hand as the main gaskets don't fit properly and overhang into the main venturis and internal vacuum galleries. The Mikuni also suffers from water choke mechanism failures which are really difficult to replace (the wax pellet housing corrode out + the inner seals fail if they are overheated/run without coolant and generally fail from age). Their primary function is low to mid range torque but on highway driving strangle the engine and are well, terrible for any kind of performance due to the pollution gear on them (this isn't just the carb but the exhaust gas recirculation into the intake as well) You can delete some of the EGR junk on the stock carb which will improve engine efficiency but you're still stuck with the biggest stumbling block of the Mikuni's CFM rate. The Weber 32/36 does a great job of fuel delivery as it can keep ahead of the demand for CFM that the 4 cylinder engines need across the rpm range (it will trade a small loss of low rpm torque for the improvement of power from about 1500 rpm onwards). They're easy to pull down and rebuild, the kits are cheap, the electric chokes eliminate coolant hoses and the problem with the wax pellet choke on the factory carb, and the 2.0 - 2.6 engines respond very well to these carbs with both power and fuel economy when they're tuned properly.