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62BT7 TriCarb Mixture Adjustment

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H

Hondo Hernandez

Senior Member
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Mixture was so rich that plugs fouled and engine failed to start. Cleaned plugs and we're running again; however, exhaust shows very rich. What is recommended procedure for properly setting mixture? Is running the adjust nut to the top max lean or max rich?
 
Hello HH,

the nut to the top is maximum lean.

The base setting is two full turns down from full up (jet tube flush with the bridge) You should not need to adjust very far from that setting. Just check that the needles are correctly set in the piston, the shoulder should be flush with the bottom face of the piston.

Alec
 
HI H.H, Just follow Piman's instructions and you will have your carbs set up in a nick of time.---Keoke /ubbthreads/images/graemlins/yesnod.gif
 
Thanks 7777.........there are a few differences in the HD and HS, which I have, but I think I can make the translation. Can't wait for Sat AM so i can get started on this and get 'er on the road.
 
Thanks Piman This is a big help. Someone yesterday told me to check that the jet raised and lowered when choke was set and released. If it stays in choke mode, which is down I think, then too rich mixture would be a problem. I've never checked this. Never the less, i do need to adjust the mix nut as you say. Thanks again.
 
Hello H.H.,
they really are very simple and do not need constant adjustment either. Keep the pistons and dampers clean inside (using a solvent cleaner, not abrasive)
Once the mixture is set, balance the airflow, which you can do with a tube to judge the 'hiss' so that all sound equal or use an airflow meter and you are set.

Alec
 
[ QUOTE ]
Hello H.H.,
they really are very simple and do not need constant adjustment either. Keep the pistons and dampers clean inside (using a solvent cleaner, not abrasive)
Once the mixture is set, balance the airflow, which you can do with a tube to judge the 'hiss' so that all sound equal or use an airflow meter and you are set.

Alec

[/ QUOTE ]

If the tri-carb is anything like the BJ8 it is an absolute pain removing the filters to do the airflow balancing, and then you are reliant on the filters airflow being identical to keep the balance when they are re-fitted.

I found it VERY easy to set up by inserting identical lengths of thin brazing rod into the dash-pot having removed the oil damper pistons, and bend the rods to point to each other. As the throttle is opened (gently) the sliders will rise, and should go up in unison keeping the rod ends at the same height. If the setting is out on one carb it will not follow the others. This way the air filter stays on and you are using the 'feedback loop' of the SU carb design to equate to airflow.

AWEM
 
all this neg stuff about tri carbs is a bummer,it aint that hard,by the way the most kick a-- runnin healey i ever owned was a tri.aside from mikoni carbs, this is what i feel is the best set up,o.k. gregw eat me up alive,remember $ equation! /ubbthreads/images/graemlins/smirk.gif
 
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Thanks AWEM this sounds like a great way to see that flow is balanced. Hondo

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Quevo Yo!-You can buy a tool like that which is very inexpensive from most of the LBC suppliers they are very handy to have on Hand.---Keoke
 
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Thanks AWEM this sounds like a great way to see that flow is balanced. Hondo

[/ QUOTE ]

Quevo Yo!-You can buy a tool like that which is very inexpensive from most of the LBC suppliers they are very handy to have on Hand.---Keoke

[/ QUOTE ]

I was trying to buy some last year here in the UK but no one had any. The thin brazing rod works just as well and if you kink the end that goes into the damper cylinder so it grips the wall it is an absolute doddle to use as the slight friction lets you set the other ends 'in register' before you start the engine. Make sure each rod is identical in length so that their weight is the same so that they should rise in unison when the carbs are balanced

Andrew
 
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o.k. gregw eat me up alive,remember $ equation! /ubbthreads/images/graemlins/smirk.gif

[/ QUOTE ]
I've got 5 gallons of barbeque sauce and 45 bags of charcoal on order. Should be here next week…
mad0090.gif
 
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