Jump to content
Ultimate Subaru Message Board
jonpaul03

My 78 BRAT project....

Recommended Posts

Does anyone have any experience with a Weber offroad carb on the BRATs? Do they typically dump fuel into the primary? Is there an exact way to route the vacuum lines considering the stock carb required more vacuum connections?

Share this post


Link to post
Share on other sites

Does anyone have any experience with a Weber offroad carb on the BRATs? Do they typically dump fuel into the primary? Is there an exact way to route the vacuum lines considering the stock carb required more vacuum connections?

I'm having trouble with my vacuum lines. I have no idea which one goes where and it is running like garbage. Wants to die as soon as I try to let the clutch out. Under heavy acceleration its happy, but anything less than that and it bogs and wants to die.

Share this post


Link to post
Share on other sites

It has been a while since I have posted on here. I was having issues with the electric choke on the Weber Carb since I last posted. I ended up replacing the electric choke with a manual choke and now I have control!!! The Weber seems to be operating properly now with the new choke and the placement of the vacuum hoses.

 

 

post-51275-0-74179800-1404572889_thumb.jpg

post-51275-0-10992000-1404572904_thumb.jpg

post-51275-0-49393500-1404572917_thumb.jpg

Share this post


Link to post
Share on other sites

Once the choke was figured out I decided to put the BRAT on ramped and block up the back... I pressure washed the hell outta it and scraped the stuff with edges. I rust-reformed it all and still in the process of undercoating it. I am gonna leave it on the ramps so we can fab an exhaust. Any recommendations on a muffler to replace the pre-muffler under the driveshaft? I think I am gonna run one new age muffler rather than a pre-muffler and a muffler. Ideas?

 

 

 

 

post-51275-0-63891600-1404594281_thumb.jpg

post-51275-0-55102500-1404594288_thumb.jpg

post-51275-0-75028400-1404594296_thumb.jpg

  • Like 1

Share this post


Link to post
Share on other sites

And.........I also replaced the gauges. I went with the BRAT gauges with a tachometer. I had to run a new wire to the coil, but it works flawlessly! Plus, they are way more sexy.

 

 

post-51275-0-40357600-1404595181_thumb.jpg

post-51275-0-65786600-1404595187_thumb.jpg

post-51275-0-05905300-1404595195_thumb.jpg

post-51275-0-34223600-1404595202_thumb.jpg

Share this post


Link to post
Share on other sites

I finished the exhaust this weekend! I decided to go with the FlowMaster HP-2 Series muffler. I also decided to take the tailpipe out of the driver side instead of running it under the CV and out the back.

 

 

 

 

post-51275-0-35240100-1407592530_thumb.jpg

post-51275-0-41303500-1407592537_thumb.jpg

post-51275-0-70664800-1407592543_thumb.jpg

post-51275-0-53841600-1407592549_thumb.jpg

post-51275-0-72528200-1407592634_thumb.jpg

Edited by jonpaul03

Share this post


Link to post
Share on other sites

Glad you got it worked out.. Nice build.  The electric choke on mine would do the same thingmy problem was I tapped power from the wrong thing so it never worked. Once I figured that out it ran like a champ. 

  I am not sure about the 78s but the pre muffler on the newer cars is a resonator which helps knock down some of the drone at higher rpm.  So how does it sould the flowmaster? got a clip?

 

Mike

Share this post


Link to post
Share on other sites

Thank you! I like having the control with the manual choke more than the electric choke. The Flowmaster definitely sounds more aggressive and a bit louder than stock, but overall it sounds pretty good.  The clip I have is with the BRAT sitting in the garage, so it echoes more. The sound in the clip isn't completely accurate.

Share this post


Link to post
Share on other sites

I had to fabricate an EGR tube and it cracked at the lower 90 degree angle going to the head. I either need to fab another one or delete the EGR all together....

Share this post


Link to post
Share on other sites

Has anyone seen 1st gen Brats sell recently? If so, how much were they going for?  I don't necessarily want to sell mine, but I am curious of what the market is like now.

Share this post


Link to post
Share on other sites

Hey guys! I have been away for a while and now that I am back I have something to ponder with yall. I have an issue with my BRAT and if yall have any advice or have experienced the issue I would love to hear it.

 

It all started shortly after my EGR tube failed and the accelerator pump on my Weber carb failed. I could not get the brat to start unless fuel was poured into the ccarb and it was ran with the choke fully engaged. So.....I will break it down by series of events to follow:

 

1. Replaced the EGR tube and accelerator pump on the Weber. (problem still persisted)

2. Replaced the original fuel pump with a new one from rockauto. (problem still persisted)

3. Rebuilt the Carb (problem still persisted)

4. Checked/cleaned the sparkplugs which were covered in carbon tar (problem still persisted)

5. Drained the gas tank and replaced fuel with fresh fuel +some stabil for removing moisture (problem still persisted)

6. Replaced all of the fuel hose under the hood with new hose and fuel filter (Problem still persisted)

 

I think I have pretty much eliminated a fuel issue. Any more thoughts on what might be the issue with my BRAT? Before the initial problems the BRAT was running great. It idled around 900 rpm and had very nice throttle response. It didnt smoke or run rich. I am looking for assistance trapping the gremlin! Any words of wisdom are greatly appreciated!!!!

Share this post


Link to post
Share on other sites

It sounds like the carb to me. I have the weber also and she idles high, even with the idle screw backed all the way out. I think that is has

has to be the carb. My Brat ran like a swiss watch. Then I had problems found out the diaphram in the dist. went bad. Replace it and upgraded to the

Weber and she has never ran like she did. Still runs awesome when your foot is set, but even with a fresh built ea81, she still doesn't

run as smooth as she has before.

Just my 2 cents.

I would think it was the carb but you said you rebuilt the carb. I did the same with mine but I keep thinking it is a carb problem for me

or I have a vacuum leak.

Share this post


Link to post
Share on other sites

The weber looked great when I tore her apart. I checked the vacuum hoses and they look good. My weber didnt idle great until the valves, timing, and fuel/air/idle screw were adjusted good, but after I replaced the accelerator pump and EGR tube it hasnt ran good. I am almost thinking its a timing issue or distributor issue...... not sure though

Share this post


Link to post
Share on other sites

Mine drives me mad. It isn't like there is all these vacuum lines or something. It is pretty basically. My ea81 has maybe 7000 miles on her

and she drives great other than she idles high and lacks the real power that all want in an Ea.

Share this post


Link to post
Share on other sites

Mine just wont idle without the choke fully engaged. It ran perfect before I replaced the EGR tube and accelerator pump.... doesnt make sense. 

Share this post


Link to post
Share on other sites

I need a sanity check!!! Testing a fuel pump by direct connecting it to the battery (with it still hooked up to the fuel lines) should still pump right? I have tested many unhooked this way, but never while installed. Mine clicks once and doesnt pump....clicks again after a few seconds, and then will click again when applied to the battery. It will not do anything between clicks while touching the leads to the battery... Am I going insane, or should it just pump when I apply the leads to the battery????

Share this post


Link to post
Share on other sites

Hopefully someone responds to this..... Has anyone eliminated the reserve tank and overflow limiter located on the right side/bed of their BRAT? IDK why it is necessary. And.....I have completed a master rebuild on the carb x2, replaced fuel lines, checked under the hood vacuum, replaced plugs, and replaced the fuel pump....still wont run.  

Share this post


Link to post
Share on other sites

Once the choke was figured out I decided to put the BRAT on ramped and block up the back... I pressure washed the hell outta it and scraped the stuff with edges. I rust-reformed it all and still in the process of undercoating it. I am gonna leave it on the ramps so we can fab an exhaust. Any recommendations on a muffler to replace the pre-muffler under the driveshaft? I think I am gonna run one new age muffler rather than a pre-muffler and a muffler. Ideas?

Awesome job on BRAT so far. I admire it. Was wondering where you got your dashmat from?

Share this post


Link to post
Share on other sites

Thank you! Now if only I can get it to run again.... The dashmat came with the BRAT when I purchased it. I am not sure where it originally came from. 

Share this post


Link to post
Share on other sites

Hopefully someone responds to this..... Has anyone eliminated the reserve tank and overflow limiter located on the right side/bed of their BRAT? IDK why it is necessary. And.....I have completed a master rebuild on the carb x2, replaced fuel lines, checked under the hood vacuum, replaced plugs, and replaced the fuel pump....still wont run.  

 

 
 

I have a diagram from my 78 Brat owners manual and It looks like there are two reserve tanks.  Also from what I have found is that there are quite a few different fuel setups for each year.  California models, High Altitude, 4wd, 2wd, and any combination in between.  Small differences like added check valves and completely different routing of the vacuum lines.  Autozone has a lot of literature on their website and some good diagrams.  You have to look closely to notice some of the differences.

 

https://www.autozone.com/repairguides/Subaru-ff-1-1300-1400-1600-1800-Brat-1970-1984-Repair-Guide/Vacuum-Diagrams/Vacuum-Diagrams/_/P-0900c15280065a54

Edited by Weebles

Share this post


Link to post
Share on other sites

Thank you! These diagrams are helpful, but I'm not sure how beneficial they will be for the issue I am having. My 78' ran perfectly before the EGR tube and accelerator pump went bad. I replaced both and now she wont run unless choke fully engaged. So...I did a master rebuild on the carb, replaced fuel pump and lines, checked vacuum lines, and flushed the tank. Still wont run without choke fully engaged. (Thats after getting it to start with pouring fuel into the carb)

Share this post


Link to post
Share on other sites

So..... I have continuity between all associated components and I still do not get power to my fuel pump. I have replaced the Voltage Regulator and pump itself. The generator tested good and I replaced the points/condenser. Battery is good and all fuses replaced as well. I currently have 2 pumps hooked up to test different grounds and still nothing. I bypassed the fuel tank and ran the fuel line to a gas can....still nothing. Any ideas??????

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×