rebuilding the EA82 Hitachi

[JonOfScio]

Tomorrow I'll have the time and parts to rebuild our carb on the '87 as it seems to be leaking from the accelerator pump, and possibly elsewhere. the secondary doesn't seem to kick in, and I have vacuum leaks to diagnose, so I'll be making up a vacuum wiring diagram to go along with the digicam pictures.

 

Now for the question. There is three main parts, the top, the metering block, and the bottom. The bottom part of the carburetor, which doesn't seem to pertain (I haven't taken it apart to confirm anything yet, but the last time I did take an EA81 or 82 2bll hitachi) doesn't seem to have anything to do with the metering of the a/f ratio... I was thinking about polishing the ports in it (NOT enlarging them), along with enlarging the ports on the plastic thermothingy spacer to match the carb, and polishing the carb section of the intake manifold. I will be replacing the intake manifold gaskets as well.

 

Anybody think it is worth the time? possibly a worse side effect? anybody done something similar? or should I just stick to cleaning and rebuilding the unit? should I do the mechanical secondary mod? would it be worse on gas mileage? any tips on anything else? I already took off the aircleaner and fixed four leaks...

[NorthWet]

Polishing the throttle plate segment probably won't get you anything. Matching the gasket, etc might be worth something. Changing the vacuum actuated secondary to manually actuated will hurt mileage and power.

[subarunuts]

Couple things on EA82 Hitachi's. The secondary vacuum actuators fail, and the choke spring's wear at the point where they actuate the choke plate - most of the ones I have seen in the JY the end is already broken off, and the spring will no longer engage the lever at all. Sometimes you'll get lucky and find a car where it has already been replaced, or a car that was garaged or from a warm climate. The upper body gaskets get knarly, and occasionally you'll run into one where the throttle base is sloppy - it's cast iron, and the shafts are brass. It's easier to get a new throttle base from the JY than to replace the shafts. I think roo-builders sells bases tho. The accelerator pump and seal come with any kit, and I have found that the float and float needle need to be carefully checked to make sure there's no binding - wear on the needle can cause this. Also note there are two tabs on the float - one for max travel in each direction. Can't let it go too far down or it will stick in the open position.

[JonOfScio]

When the carb is out, I'll turn the throttle open all the way, and attach a vacuum line to the actuators, and suck to see if they move. Will I have enough vacuum to it to move it if it should be in good condition?

 

I'll make sure to check all of the shafts and various parts that move for wear and sloppage. I'll be taking step by step pics for people who also wish to rebuild their carbs... I've already done a couple EA81 hitachis and taken apart an EA82, which is very similar. (of what I can remember)