EA81 help and setup preference?

Discussion in 'Subaru' started by fusionfab, Aug 10, 2014.

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  1. Aug 10, 2014 #1

    fusionfab

    fusionfab

    fusionfab

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    Hey Everyone, hoping to get some input from those who have experience with the EA81.
    I recently (a couple months ago) purchased a fresh rebuilt EA81 with redrive all receipts included. It has the original manifold but the upgraded 2 barrel weber on it. Now I just purchased an Avid MKIV already equipped with an EA81 this week that was having engine issues. I ran outta time today and will be back at it in a couple days but I've run the engine for a bit today and noticed that it idles decent but doesn't want to rev up to potential, when it does I'm getting popping on the left side. All cylinders tested between 112-120 psi. Of note, this engine is equipped with twin BING carbs, anf further the previous owner just purchased this entire engine package from a company who claims to have rebuilt everything. However he believes differently and I will not name the company it came from as its only hearsay to me.

    After running the engine for a few minutes I noticed the right side to be heating up normally and the right side not so much. One side egt warming up, other side not. So I'm assuming either both left side cylinders or just one is not firing. I didn't have an extra hand today to check for spark so will get that done. But would like to hear if anyone has had similar issues like this that was a result of these carbs or had anything to do with synchronization?

    My second question, would anyone suggest I install the the other engine with the 2 barrel? Or Install it and using the twin BINGS?
     
  2. Aug 10, 2014 #2

    Hot Wings

    Hot Wings

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    I'm no Subaru expert but I have seen more than a few of these that showed good cranking compression but in fact had some pretty bad exhaust valve leaks. If you can to a leak down compression test it will give you a lot more diagnostic information.
     
  3. Aug 11, 2014 #3

    fusionfab

    fusionfab

    fusionfab

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    Ok thank you. I will look at doing that today. I've taken apart the carbs and throttle control and the carb are absolutely filthy with gunk buildup as well as cracked and broken seals, additionally the one carb had the mixture screw in all the way...and tight. The throttle cables and linkages was not setup nicely, twin cables going through the firewall and attaching to the pivot tube and they weren't pulling evenly and slipping back. So I'll completely rebuild the carbs, redo the throttle linkage, do the leak down test and go from there.
    Thanks
     
  4. Aug 11, 2014 #4

    akwrencher

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    Sounds like you found the smoking gun. Doesn't take much to screw up a carb. Let us know how it runs with rebuilt ones :)
     
  5. Aug 12, 2014 #5

    Hot Wings

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    Does indeed. If the carb repair fixes the problem the leak down might only be needed for peace of mind.
     
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  6. Aug 12, 2014 #6

    fusionfab

    fusionfab

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    I also forgot to mention that the choke control for these were disconnected and just strictly using the primer. So the chokes were positioned to be on the springs in the closed position and I recall when removing the one the spring wasn't hooked up and the choke, I believe was partially open.
    i will be doing the test strictly just for a piece of mind. I'd like to at least eliminate every issue and also just no the current state of each.
    But once I get the carbs rebuilt I'll let ya's know.
    Any advice on which throttle setup to go with? The rotax dual pull? A dual to single puller block?
     
  7. Jan 12, 2015 #7

    akwrencher

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    Any update on how things went?
     
  8. Apr 28, 2016 #8

    fusionfab

    fusionfab

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    akwrencher
    Just seeing this now, sorry about that.
    I got the carbs all rebuilt and they were a disaster inside and out full of gunk and clogged right up. Got them sparkling clean all rebuilt. I had them installed and redid the throttle linkage to a dual to single pull so both carbs can remain in sync. I ran it briefly without fine tuning the sync and the engine appeared to run much smoother and more powerful. Still lots of fine tuning to do which bring me to another thread that I'm starting now.
     

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