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78 brat carburetor woes


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Long story..... but now I can't get the car running. I have no idea even what type of carb I have.... nor how to tune it.

 

2 weeks ago... the car ran "ok".

 

Failed emissions...... badly. Burns VERY rich

 

Ran some 44k through it to clean out the fuel system... dumped some alcohol in it to "hopefully" get it through emissions... it did MUCH better.... but still failed.

 

Filled it up with mid-grade gas.... and it started running horribly for a week now.

 

Finally today.... I get to actually take it apart and try to get it to burn a little a little cleaner.... and thats when the REAL problems started.

 

Now.... it fires up for a second and then dies off.... not even pumping the gas will keep it running. In fact, if I even touch the gas, it won't run at all.

 

The linkage to the primary air valve works horribly... the valve is stuck on full open. I did manage to tweak the linkage arm a bit to get it close further and only open when the accelerator is pressed. worked great for awhile.... but then when the car warmed up, I cant get it running.

 

I reset the distributor back where it has always been... fully clockwise... thats the way it's been since I bought it.

 

Oh..... and theres no fuel coming out of the secondary.... at all.... it's shiny clean in fact.... and the linkage to the secondary (closest to the cab) is completely flopping in the wind... not hooked up to anything.

 

I can only find 1 adjustment screw..... Just one. I "think" it's an idle screw on the front side... but I'm not sure... I can't find anything else anywhere. How am I supposed to adjust the mixture on this thing? It has always burned SUPER rich

 

I'm throughly pissed... and tired of this car. can anyone point me in the right direction? I'm ready to just buy a new carburetor. Does anyone have any resources or links?

 

Pics.... what is it?

 

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IMAG0093.jpg

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I got it running... but only if I hold my finger on the air valve... and hold it closed.

 

Once I let go... It opens, and the car stalls.

 

the idle is crazy high.... and the idle screw is all the way out.

 

..... and the entire linkage mechanism for my secondaries is completely missing..... and it's not flowing any gas anyway.

 

I'd say I need a new carb.

 

Suggestions on where to buy one?

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Do you *have* to go through emissions with a stock carb? Can it be a Weber? They will pass a tail-pipe sniffer when setup correctly (with a good 3-way catalyst installed).

 

If I were you - I would figure a way to hide a Weber DGV or a Holley 5200 (Weber copy- cheap on ebay) under the stock air filter and get it running with that. Your Hitachi looks like a nightmare and quite frankly the emissions police requirements are pretty loose usually and there's plenty of room for a brand-new, tuned up Weber to slide by. It might not do as well as the stock carb but typically from what I've seen even 10x what a perfectly running stock carb puts out will still pass.

 

Check rockauto.com for a replacement stock carb - I'm pretty sure you won't like the price and I'm not at all confident that will totally fix your problems. There are so many accesory systems to the Hitachi's that it might not totally be the carbs fault. The whole engine bay is over 30 years old afterall.....

 

GD

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No.. I'm sure I can get a weber through.... don't want to spend the $ on one though.. nor do I want to deal with any "conversion" issues either.

 

This car is rediculously slow.... so a couple more hp isn't worth it to me.

 

Just the stocker is fine. I've found a new (rebuilt), flow tested, lifetime warrantee carb for about $190.

 

Better deal somewhere else?

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There aren't any conversion issues - it's a pretty straight swap. Bolt on the carb, hookup a few vacuum lines (like 2) and the PCV. That's pretty much it on the EA71's. Adjust the choke and the idle speed/mixture - which is simple.

 

Last Weber I did for $190 - good used carb, rebuild kit (they are simple), adaptor plate, couple jets, and a new electric choke and air filter.

 

Problem with the stock carb is all those hoses and ancillery systems that may be the problem rather than the carb - thermo-vacuum valves, anti-afterburn valves, hoses, etc. That's a nightmare and getting it to run right will be a challenge - plus you would be very surprised at how much performance you get from the Weber. It's not the HP - it's the progressive linkage and increased low-end torque that you want. Personally I can't bear to drive the stock carbs - I won't own one with a stock carb anymore.

 

GD

Edited by GeneralDisorder
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Thanks all. I'm familiar on the advanatges of weber carbs... I use to run dual webers on one of my old 914s. The other one had dual dellortos... and I missed the webers.

 

The best price I've found on a weber was nearly $400.

 

The best price I've found on an OEM was $190. - flow tested, pre adjusted, with a lifetime warrantee.

 

I understand it's pretty complex system... but everything else seems to be in good working order and working correctly, including the PCV, fuel system, and vacuum lines. The carb, the jetting (or lack thereof) and the linkages (or lack thereof) seem to be the problem. I figure it will be a good start to KNOW it's done right, and then I can nickel-and-dime little things afterward as they pop up..

 

Instead... it looks like the PO had the POS carb set to actually run on only the primaries, with the settings completely..... well....... "wacked"

 

So I'm going to start from scratch. For $190 it's worth it to me.

 

Regarding the Weber, I can maybe squeeze a couple more HP out of it.... which will put me at..... maybe 70hp? LOL

 

I drive a 385hp car on a daily basis... just about anything is going to be "slow" by comparison.. and the extra couple hp just isn't worth it to me.

 

Having never known about the complete LACK of the secondary portion of a carburetor until just yesterday... I'm certain that the Brat isn't nearly as "slow" as I thought..... so any improvement will seem much better than it actually is.... so I'm excited about it.

 

Any suggestions on a beter place to buy an OEM carb for better than $190?

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As GD said the Weber is probably your best bet, but if you are set on replacing it with another Hitachi you should get one for an '84. They are similar to your original but better...relatively speaking of course.

 

I agree with one minor difference - I actually prefer the '83 Hitachi. The differences are small but the '83 version has a better (IMO) choke setup. But I despise them all for their vacuum secondaries and tiny barrels.

 

GD

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If you get an '83 Hitachi it will bolt up and you can strip it down to just about the same config as a Weber. That's the route I would go. I even converted the last one I ran over to a manual choke. It actually ran quite good for what it was - you can also wrap a bit of wire around part of the linkage to cause the secondary to open progressively.

 

GD

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...So I'm going to start from scratch. For $190 it's worth it to me....

...Any suggestions on a beter place to buy an OEM carb for better than $190?

 

You're Searchin' for a New or a Rebuilt one, isn't it? ... but did you Consider the Option to Obtain a Used (Weber) one in a Junk Yard and Rebuilt it? it will be Cheaper.

Also the Weber Doesn't add too much HP, but a Greater Low-end Torque and Acceleration.

Kind Regards.

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