Subaru EA81 Carburetor question.

[JimB]

Hi All,, I am Jim Bauder from Massachusetts and have been flying my Brock/Bensen for many years with the Subaru EA81.
I have been using a Carter 2 barrel carburetor which works very well. But I am interested in knowing if there is a better one
to use.. My EA81 is a direct drive with a Tennessee prop.
Any information would be greatly appreciated.. Thanks. Jim Bauder

 

[j4flyer]

Jim, if I remember correctly I was using a 1920 Holley on mine. I believe it was a single barrel. I did have a redrive. I believe the stratus engines used two separate altitude compensating motorcycle carbs. I liked the altitude compensation idea but, I didn’t like the added complexity of twin carbs.

 

[JimB]

Hi Thanks for your reply. I initially had a single holley carb on my EA81,, which is what I used on my Mac.. But was recommended to use a 2bbl carb for better efficiency .

 

[JimB]

Hi,,, I am looking to find the best carburetor for the EA81,, is there anyone out there that can help me..
Thanks,, Jim

 

[JimB]

Does anyone know how to get in touch with Don Burchard?

 

[okikuma]

Converting The Subaru EA81 Engine For Aircraft

A very professional auto conversion of the Subaru EA81 engine by one of the many fixed wing pilots happily racking up the hours. Don Bouchard talks with Don Hansen about how he converted an EA81 for his Karatoo.

www.buildagyrocopter.com

 

[JimB]

Thanks OKikuma this is a very interesting article . IT seems like the EA81 went through extensive modifying to get
high performance, so not sure the carburetor that was specified would be what I would use on my stock EA81.

 

[gyroplanes]

Hi Jim,
Got your voice mail and don't have anything to add. I own an EA81 conversion, on a stand (for sale, cheap). I also had an EA 81 on a gyro that I sold. Neither engine was flown and I sure don't know what they on them except that they were side draft single barrel.

 

[JimB]

Thanks Tom , my engine has been running great, since '96 , never a problem, but I am using a weber 2bbl carb,, which seems to be running a little rich.
I initially had a 2 bbl Motorcraft carb ( I think , recommended by Don Bouchard) which worked great. Might go back to that.
Jim B

 

[gyroplanes]

Doggone it! I was right near my EA81 an hour ago.... shoulda looked

 

[JimB]

Hi Tom,, I would be curious about your motor. Is it an EA81, is it a direct drive, does it have a prop hub,, does it have hydraulic lifters or
solid lifters and is there a carb on it.. etc.. I bought my motor from a junk yard in '95, installed on the gyro in'96,, been running ever since

 

[Kevin_Richey]

Jim: Admiring your simple, direct drive Bensen!
How is your prerotator powered off the Subie? It appears to be a straight shaft extending up to the ring gear...

 

[JimB]

Hi Kevin, there is a double pulley on the front of the engine,, I used a lower unit of a 3hp outboard motor as a right angle drive mounted above it driven by a belt when engaged by an tension arm. here are a few pics,,works very well.

 

[Rowdyflyer1903!]

Does anyone know how to get in touch with Don Burchard?

Yes, I will be seeing Boo tomorrow morning. 2024/12/15. I can ask what carb he uses. By the way he is 92 now and still quite active.

 

[JimB]

Hi, Thanks for the info,, i remember meeting him at Mentone and in Brookville. I remember being interested in the Subaru because of him,
and the work of Tony styles and Helicopter Ed . I have been running the Subaru ever since. I crowding 81 myself.
I also would be interest in any information about a prop hub for the Subaru,, since the one I have was from Tony Styles,,
thanks so much, Jim

 

[JimB]

I meant to say I happy to hear that Don Bouchard it still active and going strong,, He is definitely the pioneer in Subaru development for the gyrocopter. Because of him,, I have been running my EA81 since 1996 with no issues.

 

[Rowdyflyer1903!]

Don celebrated his 90th trip around the sun Dec 23rd. I spoke with him two days ago. Still laughing at my jokes. His wife fell and broke her right arm on Christmas Day, So Don is staying close to the nest.

 

[JimB]

Hi, thanks for the update... Happy birthday to Don. And I hope his wife recovers soon.

 

[Rowdyflyer1903!]

Hi, thanks for the update... Happy birthday to Don. And I hope his wife recovers soon.

Don just called and I finally remembered to ask about the carburetor type for the EA81 Subaru. To his best recollection it is a Weber two barrel with a 52 mm primary and a 34 mm secondary. This maybe reversed as the smaller one may be the primary and so on. I seem to remember him using a Ford also but this is certainly unreliable from my memory from a very distant conversation. Don said he will check his records. Bless him his wife fell and broke her arm. They are struggling with life a bit right now.