[Healeys] Carb Adjustment Help Requested - BJ8 MkIII
engl at accesscomm.ca
Mon Aug 14 13:00:29 MDT 2017
The photo may be misleading - the jet top is below the jet sleeve. This is with the jet adjusting screw fully off of the lobe (i.e. jet will not go any higher).
I checked the needle valves yesterday and they seemed good (looked almost brand new). I replaced them with Grose Jets anyway to be on the safe side.
From: Bob Spidell [mailto:bspidell at comcast.net]
Sent: August 14, 2017 12:39 PM
To: Bob England; healeys at autox.team.net
Subject: Re: [Healeys] Carb Adjustment Help Requested - BJ8 MkIII
Well, so much for my recollections. OTOH, I've seen conflicting info in different SU manuals. Have you checked your needle valves? A leaky one (or two) would mean extra fuel getting dumped in the carb(s).
The photo appears to show the jet top ABOVE the jet sleeve; I believe it should be a mm or two below.
On 8/14/2017 11:30 AM, Bob England wrote:
> Thanks Bob
> Attached PDF file is what I went by, but what you say makes sense. Lowering the needle will lean out the mixture (if I have my theory right), particularly with the jet sitting slightly lower than the diaphragm shaft when it is as high as it will go (see photo).
> When you say you'd try a smaller gap, are you thinking the "0.028" previously mentioned (i.e. between stock "0.025" and the larger "0.035" I had mentioned)?
> I really appreciate all the help I am getting from everyone on this question. Truly amazing. The PO, a very good friend (who I was too embarrassed to call on this as I figured I'd screwed up his car!) has offered some insight and I'll find out more from him this evening.
> -----Original Message-----
> From: Bob Spidell [mailto:bspidell at comcast.net]
> Sent: August 14, 2017 10:01 AM
> To: Bob England; healeys at autox.team.net
> Subject: Re: [Healeys] Carb Adjustment Help Requested - BJ8 MkIII
> Where did you set the needles in the vacuum pistons?
> BOTTOM GROOVE ON NEEDLE JUST ABOVE BOTTOM OF PISTON (SO YOU CAN'T SEE THE GROOVE).
> >>> I think this may be the problem. I don't have my SU books handy, but IIRC you should set the top of the groove level with the bottom of the piston. I remember doing just this and it made a difference, esp.
> at idle.
> ON THE JAGS, I SWITCHED TO A 35 GAP WITH THE SPORTS COIL OVER A 25 GAP AS THIS SEEMED TO BE THE RECOMMENDED APPROACH. DO YOU THINK A LARGER GAP WOULD HELP?
> >>> I'd try a little smaller gap, just to see. Also, if you have the original coil and it was working, I'd slap it back in.
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