EA81 Hitachi carb baseline or what is wrong?

[RatCamper]

G'day.
I've got a bit of an issue with an EA81 of unknown history. It's running really, really rich. To be honest I've never dealt with a Hitachi progressive but I am familiar with other carbs including Weber progressives.

when testing it ran out of fuel. As the float bowl was emptying, just before the engine died the revs picked up and the engine smoothed out. It's also blowing a lot of smoke, and badly fouling plugs.

I wound the idle mixture screw down until it hit the stop. When it did bottom out there was a tiny, barely perceptible pick up in revs and smoothing of the motor. still sounded like an old tractor though.

Does anyone know the baseline settings for throttle plate and mixture screws? Gregory's doesn't seem to have that. If I can't get this carb working right is there a good reason I can't get an adapter plate and put a Weber on it?

Thanks in advance.

[TOONGA]

hello ratcamper and welcome to the board the hitachi carby is a fickle monster at best and it sounds from what you are describing like it has an air leak or two. you can re kit them and run them again but having done it myself to quite a few of them putting a 32/36 weber is a way better option

the only reason you couldn't put a weber on it is the cost of a new / recon weber if you have one and an adaptor plate it is a very simple swap

there is a guide here as well if you need it

http://www.subarubrat.com/Retrofitting% ... V%2032.htm

TOONGA

[steptoe]

notice with lawn mower as it runs out of fuel with no load revs up as it leans out - similar.

Power valve may be gunked up. Run fuel cleaner or carby cleaner or rekit it.

[RatCamper]

Great info. Thanks!
I already have a Holley licensed Weber with the dual ring venturi. It is in very good condition, or at least it should be. I spent a couple of months fighting with that monster before I got it under control. Its current jetting should be pretty spot on for the EA81.

I found myself doubting the over rich diagnosis at times, but the idle mix screw doing nothing, and the stench hanging on my clothes for a day pretty much says it all.

I'll see what i can do with the Hitachi for now. The Weber would be a nice option but finding a compatible air cleaner is a bit of an issue. I also need to keep the PCV setup intact for blue slip.

The other problem I have with the Weber is the adapter. The only one I've been able to find is on eBay, and this particular one requires drilling out a couple of the stud holes on the manifold to the position / diameter of the Weber studs. I'd like something a little more easily reversible.
I'm not looking for any kind of performance increase, just a bit of reliability.

It occurred to me that I never said what this motor is in. A VW camper. If I ever get my mitts on an early 80s Subie this is all good to know too.
The Weber is from the 1800 motor I took out. So if the jetting isn't spot on it should be very close. Both motors have similar configuration, capacity and power output. The only difference really is the runners I had on the VW were one per cylinder and the same size as the ports. If you are wondering, it's not necessarily a good thing. The setup on the EA81 would be better for low end torque, cold weather running and would have a lot less fuel drop out.

[RatCamper]

I just went and gave it another good look over and let it run for a while.
There is a vacuum line which seems to be on the same circuit as the vac diaphragm on the carb, for the power valve I presume?
Anyway the line has a stepdown adapter in the end of it, then nothing. Plugging the tiny outlet with my finger made it bog further. Pulling it out completely, allowing a heap of unmetered air in pretty much eliminated the smoke and upped the revs a bit, as to be expected. I don't know what that used to be connected to.
Where the throttle base plate was set it was doing nothing. Nothing for over a turn either way. This thing is really messed up.
I also cleaned a whole heap of carbon out when I attacked it with the carb cleaner.

edit: the vac line is on the same circuit as the coasting bypass valve I think.

[TOONGA]

can you take a few photos of your setup so I can compare them to my set up that way I can tell you where and if the vaccum lines are needed.

as well what year car did the engine come out of any idea that will help as well

TOONGA

[RatCamper]

Sure thing. Sorry I was a bit wrong about the vac lines. I retraced. I was right about the decel valve, not the other bit.





Notice in the last one the open end hose and the plugged one.

[RatCamper]

Forgot the big picture:

I'm not finished yet. Cleanup comes last. I want to get it working right first.

[TOONGA]

Sure thing. Sorry I was a bit wrong about the vac lines. I retraced. I was right about the decel valve, not the other bit.





Notice in the last one the open end hose and the plugged one.

lol love the tag for the photos general_failure the line that is open should be capped or hooked to a vacuum switch for the cooling assembly on an EA81 car

the other hose goes to the carbon canister for the carby vent I take it you are using the Subaru air cleaner and from what I see your Pcv valve is still connected up the two lines near the distributor that look like they feed the vacuum advance are they hooked up and is the end capped ?

is it possible to take a photo of the engine showing the whole carby?

sorry to be a pain

TOONGA

[RatCamper]

As near as I can tell the PCV system is complete. As for whether it is working, no idea. Yeah the air cleaner is stock Subaru. The only lines I can see amiss are those two.

What sort of shot do you want of the carburettor? Which angle etc.

You aren't being a pain at all! I'm unfamiliar with some of the finer details of this motor and am seeking help. You are kindly helping me and for that you need information from me.

[TOONGA]

an overhead shot with out the air cleaner so I can see all the lines to the carby from the manifold etc, as for the pcv valve ! if you take the top plastic fitting off the rubber hose and put your finger over the hose it should create vacuum if not 2.unscrew it and give it a shake if it rattles it works if not either replace it with one that works or clean it and it should work again.

and not a problem with the help

TOONGA

[RatCamper]

Didn't realise it was on page two. Oops.

Plug the vac line with a bolt for now. Here's a top shot of the carb. Best I could do.



That blocked line from before, it just seems to come from the manifold under the carb.

Forgot to say before, I have no idea what model this motor came from. I don't know and I doubt the last owner knew either.

[TOONGA]

it is from an early 80's subaru as far as i can tell and everything seems to be in place 3 last questions

is the dizzy points or electronic what is the engine timed to and does the vacuum advance work on the dizzy?


edit // what pressure does your fuel pump push?

if it is over 5-6 psi then you need a regulator or a return line to the tank

TOONGA

[RatCamper]

it is from an early 80's subaru as far as i can tell and everything seems to be in place 3 last questions

is the dizzy points or electronic what is the engine timed to and does the vacuum advance work on the dizzy?


edit // what pressure does your fuel pump push?

if it is over 5-6 psi then you need a regulator or a return line to the tank

TOONGA

I haven't checked points or electric. I assume points because both tachs work fine on it, and a GT40 would have killed an electronic ignition a long time ago. I will check though.

I'll have to check the vac advance. Never occurred to me. At least that's easy.

I don't know what the engine is timed to. I have to figure it out as I don't have a stock flywheel or flywheel housing. There is a mark on the crankshaft pulley but I don't know what it means yet. I hope it is for 8deg btdc.

The fuel pump pushes over 8PSI, as a result it has a Holley regulator set to a touch over 2PSI. Over pressure is not the issue.

You've given me more work. That's a good thing. More possibilities. Thanks!

[TOONGA]

not a problem

Ive not mentioned valve timing or checking the compression until now either

but it could be worth doing both

TOONGA

[RatCamper]

I must have messed up a reply yesterday. Do you mean valve timing or clearance? I mean I know clearance affects duration, but if there is something like an an adjustable cam gear that I don't know about I think I'll go hide somewhere.

I'm not going to bother with compression until I've done the valve clearances. And I'm not doing them until I have a pair of fresh rocker cover gaskets sitting next to me.
I'm sure everything needs adjustment but all this reeks of an internal carb issue. Possibly bad needle valve, float turned to sink, or ???
Hopefully I'll be able to get some of this stuff knocked over in the next few days as time allows.

Question What is the difference between carbs on the EA81 and it's smaller brothers? I just want to know while looking for an adapter plate. I was offered one for an EA71 I think it was, but have no idea if it would fit.

[steptoe]

Funny how this looks like a typical EA81 that has never seen a bath Don't mnd me, I pull engines out to give them a good old clean with wire brush, scraper, degreaser and wax and grease remover, fit new seals and sump gasket so I can see things better - just anal I suppose.

Adjustable cam gear - I wish. Nope, the cam gear meshes with crank gear at the rear of the block on these babies. A comp test is a good indicator before and after valve clearance adjust at same op temp.

Thinking maybe you have not inspected the insides of the dizzy cap? A cap and rotor are pretty cheap and renewal before they let you down is good idea.Easiest and fastest tune up to try.

Know nothing of 1600 EA71 carbs. Have once fitted a 1300 carb to a 1400 and changed it from a torquey no rev motor to a revving like a 1300 with the torque of the 1400!

If it fits it could be worth a try !

[TOONGA]

sorry I say valve timing, apparently I should say valve clearances the reason I say valve timing is because that is what it was called when I was taught about the timing of engines. circa 1492

with out the proper clearances the valves open and close at the wrong time either too early or too late or in some cases not at all.

and while some people diss-miss this as rubbish you can time an overhead valve engine (adjustable pushrod motor) from the distributor all you want but if the clearances (valve timing) are wrong then the engine will run like a bucket of fecal matter

not having a dig at you Rat Camper just being my pedantic self this morning

as for the ea71 carby remember that there are many different carbys that were used by subaru on these motors. hitachi, nikki and solex being the major brands and I have seen at least 4 diferent hitachi carbys as well there are 2 different sized manifolds one with a small baseplate pre unleaded and one with a larger base plate unleaded

TOONGA

[RatCamper]

Believe it or not, that motor is post cleaning. It was caked in mud, gravel sand and who knows what else from top to bottom. I have never seen such a filthy motor (besides the old EA Falcon. The muck was all that was holding the fluids in). I hit it with the compressor degreaser, a scrubbing brush and a toothbrush. After all that I just pretty much said "Stuff it. I'll take it for a pressure wash when it's registered."

Points ignition. The cap is in good condition with minimal crud buildup, which I eliminated. The rotor is good, and the points look surprisingly fresh. As for gap, didn't check that because I ran out of time. The vac advance is working.

I'll get stuck into the valve clearances when I have a bit of free time.
It wouldn't surprise me if other things were out of spec, but there's bad running and there's this. Smoke and fouled plugs are usually fuel system ...although saying that the tach is hiccuping a little so the points need investigation. That will wait until I put the strobe on to figure out what the timing mark on the crankshaft pulley represents.

Incidentally, was I wrong about the carburettor make?

[TOONGA]

RatCamper sorry if I was abrupt this morning I had grumpyitis from the 39 degree day we are having in WA (it is probably way hotter in Perth)

the carby is definitely a hitachi I would recognise one of those little horrors anywhere
don't just assume the points are ok they may look great but the surfaces could be flogged/ burnt out. replace the condenser as well (Im assuming the dizzy has one) and make sure the timing hovers around 6-8 degrees and make sure you re-time it once you set the clearances on the valves

TOONGA