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SU HS2 carbs and fuel/float level

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Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
Hi Adrian. I saw this. Slightly different carb but similar concept I suppose. I was hoping John would address jet tube height and possible effects in variances, but he doesn't in this video. So my questions still remain...

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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
There isn't any adjustment to the height of the bearing that I know of. I don't think it would make much difference. The fuel comes out the jet not the bearing.

I would strip the carbs and make sure it was all put together properly... and with the proper parts.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

NOHOME P P
O, ON, Canada   CAN
1967 MG MGB GT "Maggie (GT From Hell)"
The jet carrier has always been flush to the bridge in my experience. Wonder why you have a low one?

Any chance the circled washer is missing?



Pete



Edited 1 time(s). Last edit at 2018-04-12 03:42 PM by NOHOME.

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Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
Interesting. I was reading up on these, and I always thought they were adjustable and the "nut" pinched the tube into place once you had it positioned. But it looks from the exploded view like it should snug up with the tightening of the nut...

I may have to disassemble and have a look, provided it unscrews. (I've read that they are sometimes impossible to remove...)

NOHOME P P
O, ON, Canada   CAN
1967 MG MGB GT "Maggie (GT From Hell)"
picture added above.

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
The circled washer wouldn't alter the height... unless it was put in the wrong place.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
I guess the question is, is it worth stripping down if it doesn't affect the mixture? Haha

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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
For all the time it would take to strip the carbs and make sure everything was right... I'd have it done already. smileys with beer

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
Haha. I already did that. Rebuild kit, new springs, jets and all. Not sure how I missed rhe low jet tube...but I didn't pull them off. Just everything else.

So i wonder if diassembly is worth that last bit. A dilemma!

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dlrhine Avatar
dlrhine Dave Rhine
South, Carolina, USA   USA
Peer
What driveability issues are you having?



If it ain't broke, I'll fix it 'til it is! winking smiley

Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
Hi Dave. Nothing horrible. I can't seem to get the mixture to be the same at speed and at idle. It's very driveable and feels great through the gears and cruising, but my idle is splashy, like it's rich...But if I lean it out to smooth the idle I'm too lean at speed.

Maybe I'm being too particular about it, but if I can get it better than it is, I'd like to try!

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
You should be at 12:1 or so at idle and 15 or 16:1 at light cruising speed. 12:1 at full throttle, full load.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

Poundingsand Avatar
Poundingsand Silver Member Peer Ebbighausen
Los Angeles, CA, USA   USA
Is there a consumer device I can purchase to measure that? I'd be interested.

EDIT: To clarify, not a gauge and sensor, but a unit with a tub stuck in the tailpipe...sounds like something I'd find plenty of use for...



Edited 1 time(s). Last edit at 2018-04-13 06:36 PM by Poundingsand.

hoggie Avatar
hoggie Mike Hogan
Oklahoma City, OK, USA   USA
One thing I noticed when adjusting the fuel mixture is the influence that one carb mixture setting affected the other. So I experimented to find a method more consistent. I found the a better method was to adjust both carbs at the same time. So I would start with the choke idle screws backed off with both carbs 12 flats down and the idle throttle set the same by listing to the air sounds with a stethoscope tube. Then when I slightly lifted the pistons and found one to speed up and the other to slow down, I would tighten the faster side by one flat to weaken and loosen the slow side one flat to enrich. The goal was to have both carbs respond the same to slightly lifting the pistons. Once I had them both acting the same, then I would enrich or lean both at the same time one flat at a time until the speed just slightly increased. Of course during the adjustments you do have to rev the engine occasionally and recheck the idle speed sounds to verify both are moving the same amount of air. Then after I was satisfied with the mixture, I would pull the choke out to the point just before the choke started pulling the jets down and using a stethoscope, adjust the choke idle screws the same for both carbs to obtain a 1500 fast idle. That seemed to work for me better than my previous attempts trying to adjust one carb at a time.

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, NS, Canada   CAN
In reply to # 3716251 by Poundingsand Is there a consumer device I can purchase to measure that? I'd be interested.

EDIT: To clarify, not a gauge and sensor, but a unit with a tub stuck in the tailpipe...sounds like something I'd find plenty of use for...

The ones with a tube up the exhaust pipe have a sensor at the end of the tube and it's connected to a gauge. Mine is made by AEM but I installed the sensor in the exhaust pipe just below the Y connector... instead of on a tube up the tailpipe.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

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