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Finally feel like I've got my carbs right

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RickB

RickB

Yoda
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After messing with them and messing with them I feel they are dialed in now.
3.5 turns out from all the way rich on each HIF4 and they are just right.
I couldn't believe I was getting so many miles on the tank of gas - it was just under 3/4 tank on the gauge at 126 miles.
So I filled it this morning. Took 3.6 gallons and no more.
That's 35 MPG with just normal driving, back and forth to Issaquah (about 30 miles round trip) all week and a couple trips to the grocery store.
The downside is I now have to connect the choke as it's a little cold blooded in the morning!
 
Congrats.

I've always been amused by people that brag that their SU equipped car starts right up without EVER having to use the choke.
 
No matter what I Put on or what I do, 27 MAX avergae (got 31 before) with 22 average: DCOE, DGV, dual SU's...you name it.
 
Yes Trevor, mine used to "start right up" no matter what.
Due to being very rich, like having the choke pulled.

I have a pretty heavy foot, there are some here who can testify to that.
These are 1.5 inch carbs and they are on a 1500 motor that's a Japanese copy of the A series British motor.
I've got about 9.5:1 compression and the engine really likes 92 octane pure gas.

The best I could get previously was 30 MPG around home, but I found the sweet spot and I still have plenty power just a bit cold on start up.
 
kellysguy said:
No matter what I Put on or what I do, 27 MAX avergae (got 31 before) with 22 average: DCOE, DGV, dual SU's...you name it.
Click to expand...

mine is about the same
 
Just checked my BE with 1275 and 3.9 rear and mileage was 35.5. My Datsun engined Midget regularly runs at 39 to 40 with a single HS6
 
Congrats! I had the carbs on my A15 Bugeye at the sweet spot once or twice, but then something else would go wrong and I'd have to fiddle with them again only to screw things up. I had it where I'd get 42MPG on the highway (hit 47 on one tank), but now I'm lucky to get 30MPG. In my defense I haven't really driven it much since the fender bender last February, so just driving it and adjusting things should make it better. I just moved down to Dallas and will be driving it down next week and plan on doing more driving this year. With the big altitude difference I will be adjusting the carbs anyway.....hopefully I can get them dialed in.
 
nomad said:
Just checked my BE with 1275 and 3.9 rear and mileage was 35.5. My Datsun engined Midget regularly runs at 39 to 40 with a single HS6
Click to expand...

Economy head?
 
Yes, Rick, I forgot to mention that I do have the good Japonese head. H 89. I'm building another with the same head as you have.

Kurt.
 
:fat: I sure like my throttle response and power range up to 7k... :fat:
 
My HS6 may be restricting me on top end power. An HS6 should only be good for feeding about 80hp. Picked up a 40DCOE and manifold for a A datsun engine for in the future. Gas mileage will be gone! BTW we just got a $0.25 hike over night!!

Kurt.
 
Where does the choke cable attach? I just got my single HIF 4 mounted on my 79 1500 and am not that familiar with it yet...

RickB said:
After messing with them and messing with them I feel they are dialed in now.
3.5 turns out from all the way rich on each HIF4 and they are just right.
I couldn't believe I was getting so many miles on the tank of gas - it was just under 3/4 tank on the gauge at 126 miles.
So I filled it this morning. Took 3.6 gallons and no more.
That's 35 MPG with just normal driving, back and forth to Issaquah (about 30 miles round trip) all week and a couple trips to the grocery store.
The downside is I now have to connect the choke as it's a little cold blooded in the morning!
Click to expand...
 
owensdad74 said:
Where does the choke cable attach? I just got my single HIF 4 mounted on my 79 1500 and am not that familiar with it yet...
Click to expand...

I was planning on attacking that this coming long weekend, but I have to admit to never connecting one on an HIF carb.
Maybe we will have to wander into the MGB portion of the forum and ask for help?
 
I just posted the question over there, I'll relay what I find.
 
Wow - thanks Trevor!
That was just posted yesterday, great timing!
 
Over on that post on the experience, I just added a scan of the HIF4 diagrams from the Haynes MGB manual. Couldn't attach it here - too big a file. Might help? But I could not find anything in two Haynes manuals on how to adjust the choke cable (or if it is necessary). I think someone told me that there should be a slight amount of slack, and that's how mine is now.
Harry
 
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