BJ8 CHOKE ADJUSTMENT

[WALTER]

Hello, my name is Walter. Because of my love for Healeys I have enjoyed reading this forum for quite some time. What a great group of people! I just acquired a BJ8 and would like to know how to adjust the choke cables. My books are useless. The choke does nothing to help start the car. The movement on the choke is greater than the movement available in the widget on the firewall. What do I do?

Thanks

 

[67BJ8]

Walter,
I am no Healey "expert", but choke adjustment is critical in getting a Healey to start. When you pull out the choke cable all of the way I believe that it injects some fuel into the engine.(That is the way that it was explained to me). you should have enough adjustment on the cable connection at the firewall to make the system operate successfuly. Maybe sombody like Dave Russell can give you a much better explanation. I am interested myself in getting a detailed description of how to properly adjust the choke.

Larry

 

[Dave Russell]

Walter,
Welcome to the forum.

Larry,
I don't think anyone is totally expert on things but collectively we can usually help.

I can't give exact dimensions but an idea of how things work. Maybe someone will have some good suggestions.

Your BJ8 should have a split choke cable & housing, one knob pulls two wires. The single to two wire transition is a splitting block at the firewall. The carb end of each wire housing is anchored to a bracket on a carb. The inner wires are attached to choke operating levers on the carbs. There is a clamp or stop near the end of each wire which sets the effective wire length.

The first part of the operating lever movement operates a fast idle cam only. As it moves further, it pulls the jet down to enrich the mixture.

To adjust;
With the choke knob pushed fully in, the wire end stops at the levers should be placed so that there is about 1/16" of free play before the stop (wire) begins to pull on the lever. (See problem below before proceeding) As you begin to pull the knob out the fast idle cam will engage. Further movement should actually lower the jet. There is a fast idle setting screw that bears on the cam & it should be set to give around 1200 rpm fast idle when the choke is pulled. There are several screws, don't turn the wrong ones. There are a slow running valve (idle mixture screw) a jet adjusting screw, & the fast idle screw.

One problem to watch for is that if the cables from splitter block to carbs have too much friction, when you push the knob back in, the outer part of the cables pops out of the splitter block instead of the wires & levers returning to the unchoke position. This drastically reduces the amount of choke wire travel & can result in poor running or the wire stops being set incorrectly.

One "fix' is to put coil compression springs around the wire ends so that one end pushes on the outer cable anchor point & the other pushes on the choke operating lever. I've heard of using a spring out of an old ball point pen. Others have found a way to more securely anchor the cable housings at the firewall end. Removing as much friction from the cables as possible helps.
D

 

[ThomP]

Having a Healey that does not have properly adjusted carburetters can greatly diminish the pleasure of owning/driving one of these vehicles. Unfortunately, this is also one of those areas where the "Complete Official" shop manual is really deficient for the BJ8 (IMHO anyway). Some time ago, I came across a supplement from British Leyland that was a great help in explaining the HD carb on the BJ8.

The BL part Number for this manual is AKD 4779, it is entitled: "Type HD Carburetter tuning, adjusting and servicing instructions". In three printed pages, this manual takes the "service person" through the entire process of setting up a pair of HD carbs. The illustrations match the carb. There is no guessing, because a type Hxx carb is used in the illustration instead of the HD. All of the illustrations are for a HD type carb.

This booklet contains instructions for tuning by ear. I have never been very good at this, so I use a "Gastester" (CO meter) in place of the ear method. I have also used the Colour Tune to adjust the carb, but the Gastester is best for me. If you would like a copy of this to help adjust your choke cables, email with a fax number and I'll fax the 3 tuning pages.

 

[Dave Russell]

Thanks Thom,
You are certainly correct.
The service sheet & several others are available here:
https://members.rogers.com/jnew/austinhealey/
D

 

[ThomP]

Good stuff, now bookmarked for future reference.

Thanks

 

[tahoe healey]

Dave, maybe you can clarify something for me. On section 8 of that HD carb manuel there is a note "on non-dustproofed carburetters, identified by a vent hole in the piston damper top, the oil level should be 1/2in AVOVE the top of the hollow pistion rod." I'd always thought it should be below the top of the piston rod.

 

[WALTER]

Thanks guys. I got it starting much better now. Part of the problem was the large bracket holding the (3)cables together, it didn't allow enough travel. I replaced it with a section of bussbar (those things inside electric panels you screw the grount wires to). Sorry purists, maybe I'll get the real part later.

Walter

 

[Dave Russell]

I have no idea what they were thinking about or if it is just an error. I hadn't read this before.

The actual oil level is not very critical. Too full & the excess will be pushed out & make a bit of a mess, but no other problem. Not enough oil will cause the damper to not work correctly.

The damper, part you insert into the cylinder, is actually a one way hydraulic valve. It provides resistance to give slow rise of the piston, but rapid closing.

Somewhere between a 1/2" low (below the actual cylinder top which is down inside the carb) & full is ok. A quick test - you can feel the hydraulic resistance when inserting the damper into the cylinder. If there is enough oil the damper will feel harder to push down into the carb than to pull up. (If too much oil, the excess will be pushed out, but it will work correctly) If you don't feel any difference in resistance, the oil level is too low or the damper valve is defective.
D

[ 04-19-2004: Message edited by: Dave Russell ]</p>

 

[waltesefalcon]

Welcome Walter. Its always nice to run into another Walter not many of us around. I drive a triumph so my methods may be a bit unrefined for you healey types. I just always fill my damper up till it is about 3/4 full then let it overflow so I am sure it will work. But like I said that is my lowbrow triumph method.

Cheers,

Walter

P.S. hope you enjoy the forum

 

[BobHorvath]

I don't know if your offer is still good for the fax re tuneing carbs by ear but I am interested. I am also interested in the complete manual. Do you know where I might buy one? bobh@claybornlab.com FAX 530 5875255 voice 530 587 4700
Bob

 

[tahoe healey]

Hi neighbor,
This re-print shows up on Ebay all the time and I think Moss has it available too.

 

[tahoe healey]

Re: BJ8 CHOKE ADJUSTMENT *DELETED*

Post deleted by tahoe healey

 

[anthony7777]

gents, just a word of caution, when insalling the "tag" end of the inner cable into the the cable ferul (looks like a small tube with a screw running into it to lock the cable) be very carefull not to over tighten, there not as stout as they look, dont ask me how i know.

 

[tahoe healey]

Bob, I drove my Healey to work today and I have a copy in the boot I will FAX it to you.
TH
Actually, I will put it in the mail if you will send me a private message with the address. My fax will not let me flip pages with out disconecting.