[Healeys] Missing under Load

[J. Armour]

Have you check carb 'balance' ?     The air flow thro each should be the
same but if for some reason the throttle shafts have moved relative to each
other you can get miss firing. With throttle on rear SU not opening the same
as thbe front it will in effect be running lean.

Joe

>> 
>> I believe it is a lack of fuel to the rear carb.  The miss/backfire is always
>> from the rear carb and down stream in the exhaust pipe serving the rear
>> cylinders.  I have used a Colortune to try and tune the carbs.  It works fine
>> on the front carb but I can¹t even get a yellow color or see anything in the
>> viewer except when it backfires.  I haven¹t found the fuel choke point.  I¹ve
>> taken the floats apart and found some crud and cleaned them out.  I¹ve
>> removed the jet from the rear carb and cleaned a very small amount of crud
>> from it¹s base.  I¹ve set the float bowls at 5/16²  and the needles work
>> fine.  Fuel flows freely from the front carb.  The only remaining point I can
>> think of is the passage between the float chamber and the jet.  I intend to
>> take the carbs off again tomorrow and clean/clean/clean.
>> 
>> Just so you know I have:
>> 
>> 1. new points, condenser and rotor
>> 2. new ignition cap, wires caps and plugs
>> 3. drained the fuel tank and replaced with fresh fuel
>> 4. tried a different coil - no help
>> 5. set the timing
>> 6. set the tappets
>> 7. checked the needles - they are standard UH
>> 8. verified the needles are seated properly and fall freely
>> 9. removed fuel filter
>> 10. changed fuel lines with new
>> 11. did a compression test - 149, 142, 142, 138, 142, 139 psi front to back
>> 12. there is no oil in the coolant
>> 
>> Thank you so much in advance for whatever light you can shed on this.
>> 
>> 
>> Price Lindsay
>> 67 BJ8
>> 



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