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Some carb advice please.

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C

Coastalman

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My BJ8 rear carb is leaking fuel directly under the carb body. One of my technical savy friends, via email, said the jet diaphram is probably the cause. Today I started to take the carburetors off the car. I got as far as taking the air filters off and the choke cables loose then looked at all the connections and figured I better ask the forum members what next. I have never taken Healey SU carbs off and apart and do not know what the sequence is to get everything apart without making a mess of it. The linkage looks quite complex. Please give me some guidance.
Also, is there a vendor someone might recommend who can rebuild the carbs. While I have them off I might as well have everything done correctly.
Thanks,
Charlie
1966 BJ8
 
HI, there are no glands in these carbs you have experienced a diaphram failure.It is readily replaced by removing the carb snd access is via the bottom screws.--Keoke
 
Both carbs have to come off together because of the linkage between throttle shafts. There are 4 studs on each--the bottom ones are a bear to reach--except the rearmost--but can be done (I go after them from under the front carb--use either a stubby or ratcheting 1/2" wrench, I can't remember which works best but there is precious little room to turn the wrench). The throttle linkage is complex, but the joints are the 'ball-and-socket' type; they can be disconnected by popping the 'ears' back on the spring clips and pulling the ball out of the socket (break the one closest to the carbs). Disconnect the vacuum advance line from the rear carb and, of course, the fuel line (you can leave the short hose between the carbs since they'll be coming off together).

Once you have the 8 nuts off the studs, and the (common) throttle linkage and vacuum advance disconnected pull both carbs straight out--the old gaskets on the insulator blocks may resist some, but can be coaxed off.

Moss Motors, BCS, etc. have rebuild kits. The 'major' kits usually include throttle shafts, the 'minor' kits don't. If there is no significant side play in the throttle shafts you should be able to get by with new jets/diaphragms and, possibly, new float valves if you like. If there is a lot of slop in the throttle shafts you can try just a new nylon bush but you may need either new or oversize throttle shafts and/or bushes. Joe Curto is a highly-recommended rebuilder--I've never used him, sorry, don't have a URL handy--or Apple Hydraulics can re-bush the throttle shafts.

SU carbs are quite simple once you understand their operating principle ('variable venturi'). Grab a book, read up and go for it, or ship them off to Joe if you prefer.
 
Thanks Keoke and Bob,
The info that they come off together really helps. I don't want to take more apart than I have to. I will check on side play. Up to now, the fuel system has been working very well. I will read up on SUs and hope I can do the repair myself. If not, I am glad there is a resouce for the rebuild.
If anyone else has any tips, they will be very welcome.
Charlie
 
If your idle was steady and 600-800RPM your throttle shafts are probably OK. I would replace both jets/diaphragms while they're out; they may have been affected by the new 'gasolines.'
 
Hi Charlie,

After you get them fixed, buy ethanol free gas whenever possible.
There are two places in Oriental that sell it.
Here is the web site to use to locate ethanol free gas stations in the US and Canada...

https://pure-gas.org/

Ed
 
Great pictures Andrea. Thanks!

Ed, the only place selling ethanol free gas here is the marina. They tack an extra 40 cents a gallon on their price and I would have to fill gas cans from the dock pump and transport them to my car. I will just have to put additive in the tank each time I fill up.

Charlie
 
FWIW, here's my experience with my BJ8 over 30 years and 110K miles of ownership.

When I bought the car, there was a vague gas smell in the boot. Eventually, I got around to replacing the tank; would have been 20+ years ago. We coated the inside of the tank with Bill Hirsh gas tank sealant. Gas smell gone.

A long time back--again probably close to 20 years--IIRC I had a jet diaphragm crack so I installed new ones.

About 15 years or so ago I replaced the flexible lines at the carbs.

I live in California and drive all over the western US, Canada and Mexico (once--getting stopped by machine gun-toting Federales was 'interesting'). California, as you may know, has experimented with all kinds of gasoline formulations over the years. I just assume that whatever gas I buy has at least some ethanol in it, and who knows what else (MTBE, patchouli oil, ?).

I do not run a fuel filter. I've been through several fuel pumps, but those were problems with the pumps' electronics. The solid-state SU I installed several years ago has performed flawlessly (but I still carry a spare with points).

I have never had a problem with any fuel I've ever burned. None. I bought ethanol-free gas at a Shell station in Burns, OR last year; there was no discernible change in the car's performance, idle, etc. I don't dump anything in the gas tank except gas.

Just a data point, in case anyone is interested. Of course, YMMV.
 
Bob, I have also run California gas with no problem. It no longer has MTBE (it tended to leak out of the station tanks and is hard to clean up), but it does have ethanol.
 
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