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Drove Bugsy home this AM

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Jim_Gruber

Jim_Gruber

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Finally got a chance to pick up Bugsy this AM between Rain Showers and Conference Calls I found a 45 minute dry window. Monsoons predicted the rest of the day. When I got home after a 5-7 mile spirited romp I pulled into garage and turned him off. Engine proceeded to diesel and run on for more than it should. Timing instructions provided by Mickey Pleasant were for 16-20 degrees BTDC. Engine has a fast Road Cam I believe. I need to do a little more driving and testing, again I had a very limited window this AM, thinking dial back the timing a click or two? And what does that translate to. Turn the Vernier dial Clockwise or Counter Clockwise?


And yes it was as good as I hoped driving him home!
 
Guys any thoughts on my dieseling / run on issue.
 
Since your engine is new (no carbon buildup), it’s likely either octane too low or idle to high. Changing the timimg won’t matter since this occurs when the ignition is off.

Idle too high high gives the engine more momentum to keep going and leaves the throttle open more.

Do you have vacuum advance hooked up on your dizzy?
 
I had a similar problem with a car, and it was due to the carbs being too rich and the butterflies not closing completely.
 
until then, while vehicle stopped and still running, set the park brake, stick it in gear, place right foot hard on brake pedal, rapid order, shut off ignition and let out clutch.
 
Idle is about 1,500 rpm. I have not messed with anything yet. Will start there. And will check to make sure no air leak. Needed to customize washers on intake manifold / LCB Header asthey are different heights. Could be a leak there. But Oh does Bugsy ever feel so Spirtely :smile:
 
1500 is high cold idle. WAY to high. Depending on cam, carbs, I would look for 700-800. Remember, idle numbers in the book were ideal based upon everything brand new factory.
 
Agree of too high and I need to see if I can get it down. Again could have a gasket leak possibly. Fettling, more fettling needed.
 
Vacuum leak is one. Too tight a throttle linkage is another (cable, right? when off, can you wiggle the exposed cable without moving the shafts?) How did you sync the carbs? If you really did...or didn't...and one butterfly is partially open.....butterflies not set correctly in the shafts and hitting the bore before they fully close.....then we get into mixture, pistons. But check the mechanicals first.
 
One issue is choke return springs are not OEM. Ordered new. That’s my first place to start.
 
If I push things to where they should be RPM’s dripbto 1199
 
Jim_Gruber said:
If I push things to where they should be RPM’s dripbto 1199
Click to expand...
Not sure I understand. Linkage or butterflies?
Either one, you seem to have a mechanical issue with linkage or butterflies.

How much slack is there in the inner cable? Can you pull it out of the outer cable near the linkage end? Do this to insure (and eliminate) the cable is not too tight.

Then, don't you have idle linkage off the choke?
Might want to disconnect the arm to make sure that is not affecting it.

In fact, do we know the choke is fully disengaged when the knob is in?
Check that cable, too, at the carb end.

Once you have eliminated throttle cable and choke cables from the equation, unless the linkage is hitting something, it's down to the carbs themselves. Idle stop screws on both? Both backed out? If they are both clear of the dog, and the butterflies won't close, then it's down to butterflies.

If the carbs aren't even close to being synced, one butterfly could actually be open enough to cause this. When I do a preliminary cold setup, I lift the pistons and look at the butterflies in wide-open condition, set the shafts so they both are. Gets you close. Then tweak from there. Not the book procedure, but a quick step I started doing long ago.
 
I need to get the correct Choke and Throttle Return springs on. That's the biggest issue right now. If I push the linkage back, RPM will drop to about 1,00 RPM. I'll let you know once I get correct Springs on there.
 
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