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Starting help?

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jerseyjoe

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Working on a 1967 BJ8 that is fighting me to cold start. Here is the quick story.. plugs new and gapped, points gapped, vacuum advance to the distributer working, fuel pump works well, the SUs have new float valves, and cleaned. I have adjusted the slow idle as per instructions, ....it starts right up on starting fluid, runs very rough cold, evens backfires thru the carbs until it warms up...then it will even out. The next day...it will start up ok. Wait a week, the problems continues......what am I missing???? I am sure it is the SUs
Joe
 
Joe - you don't say if the chokes are working to their full extent. This sounds like RDKeysor, in a previous post, who's choke linkage isn't depressing the jets sufficiently.
See if you can pull the levers up more, causing the car to start easier. If that's the case suggest you look at your choke linkage and choke cable housing flexing - IMHO they're kind of a flimsy design.


If the choke linkage operation is OK, maybe the main needles are too lean. Dave Nock of Brit Car Specialists recommends going to the richer main needles if you're using high-ethanol gas.
As an experiment, you could raise the needles in the pistons to make the car richer overall. Look in the Moss catalog, HD8 carbs for needle numbers.

Addendum: measured one of my HD8 jets - running position, down .067"; fully choked, down .138" - this is the full extent of the lever as rotated on the carb itself. Your choke linkage should approximate this.

Addendum 2: could this be aggravated by summer gas still in your tank? - it's less volatile than winter gas.
 
mixture is to weak
 
Yes it sounds too lean. I would take off the dashpots and pistons to see if the fuel level at rest is just below the jet ( blow down into the jet to see if fuel bounces back up) if not check and adjust the floats. I'd definitely not rule out points and condenser either as partially to blame. The tendency is to adjust the carbs on the lean side for a smooth idle in the summer but you'll need to enrich in colder temps as a matter of course. Make sure you have a thermostat so the engine heats to the proper temp to adjust running mixture. The Healey engine is very cold blooded in the North , eh?
Kevin
 
Brinkerhoff said:
Yes it sounds too lean. I would take off the dashpots and pistons to see if the fuel level at rest is just below the jet ( blow down into the jet to see if fuel bounces back up) if not check and adjust the floats. I'd definitely not rule out points and condenser either as partially to blame. The tendency is to adjust the carbs on the lean side for a smooth idle in the summer but you'll need to enrich in colder temps as a matter of course. Make sure you have a thermostat so the engine heats to the proper temp to adjust running mixture. The Healey engine is very cold blooded in the North , eh?
Kevin
Click to expand...
Hi Kevin , I couldn't agree with you more on the fuel mixture being to lean. I always enrich the carbs on my 65 for the winter. S U carbs can drive you crazy, but when you get them right, its a great ride.
Bobby R
 
thank you all for your input. I have removed the pots from the SUs and raised the jet until is it flush with the carb base. I secured the chokes better and plan to turn in the jet screw 2 turns to try and see if this makes a difference.
I will let you know the results soon
 
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