Engine spinning backward when killed?

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squaredeal91

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Best not to drill the Holley jets. Two reasons, the jets have a radius around the hole. When you drill them this is gone. Second, the jets may be coated for corrosion protection. Some jets were bronze, no coating.

Back in the day speed shops would have a large divided box with all the different sizes for the Holley's. You can still order what ever size you need now. Best part then was if you weren't happy with what you tried, and you did not goof them up, the shop would swap you for free, another size.
I bought a set of holley jets last year. It was a nice divided box. Was very helpful
 

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Believe I got the miss figured. Cranked it and went to pulling wires on the side the miss was on. Number 4 lit me up like they put me in a DC Old Sparkey! Throwed another old junk wire on there and she leveled out. I believe it's just to lean, Come to find out the main jets are for 70 degrees at sea level. I'm at 4300 feet so I need bigger holes. Now...to find those....or the right drill bit.
If it's jetted for sea level, it should be runnin fat at altitude. The higher up, the less air there is.
 

SirRobyn0

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Yes, Dieseling or after run is the correct term.

Find the miss first and you may well solve the dieseling problem at the same time.

Dieseling is caused by something lighting off the fuel after the key is off and the spark has stopped. Carbon can cause it. To much timing advance or to little can cause it. Higher idle speeds can attribute to it.

The standard procedure if a carb'd vehicle came in the shop doing this would be to track down the miss first. Then assuming the dieseling is still a problem, set the timing, set the idle speed and mixture.

Shakey, Does the idle speed need to be at 1,100RPM? I know if it's cammed it might need that high of an idle but lowering it a few hundred RPM might solve it.

What do you have for a distributor? Let me run this by you. If your running a race distributor with no vacuum advance can then if your setting the base timing by ear and getting close to 20 degrees (I'm picking a random number for an example), you kill the engine it's still at 25 degrees. If you had a base timing of 10 degrees and and a vacuum advance can hooked to manifold vacuum, then you'd kill the engine with still the same combined timing of 25, but when you kill the switch vacuum drops to 10 degrees, which effectively drops the idle speed.

So with that in mind you might try retarding the timing a little.

And to stop a troubled engine once and for all from dieseling is to install idle speed kicker, with the wire attached to switched voltage, so you can have the 1,000 RPM idle, but kill the ignition and the throttle blades close a bunch more.

Step one for me would be pulling all the plugs and running a compression test, then tune up parts, then troubleshoot the dieseling.

Hopefully something in there is helpful.
 

wanderinthru

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If it's jetted for sea level, it should be runnin fat at altitude. The higher up, the less air there is.
That'a what I believe as well, and it's true. I read the istructions so I could have misunderstood and am ignorant about this carb. It may be the higher the jet number the smaller the hole? Any idea anyone in Amarillo that may have a set of jets? Amarillo Offroad?
Do know when it's ran in the shop you cannot smell any gas? I mean none, spark plugs are getting grey/silver and just running pump regular gas. So???

@SirRobyn0, Running a regular ole HEI, with vacume advance. Like you said, need to get it tuned up, new plugs and wires, get the carb and timing tuned then see about the idle, will go ahead and pull it down thru all that and hopefully stop the backward spinning. Have it so high mainly for "just in case" times there may be alot going on inside this thing and the loose nut between the seat and steering wheel aint very smart.

Thanks guys, we will get it.
 

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That'a what I believe as well, and it's true. I read the istructions so I could have misunderstood and am ignorant about this carb. It may be the higher the jet number the smaller the hole? Any idea anyone in Amarillo that may have a set of jets? Amarillo Offroad?
Do know when it's ran in the shop you cannot smell any gas? I mean none, spark plugs are getting grey/silver and just running pump regular gas. So???
I'd say Amarillo Off Road would be your best bet for actually having them on hand. North Amarillo Auto Parts deals with a lot of Roundy Rounders too.
Haven't checked lately, but O'Reillys used to carry Holley jets.

Is it a Holly 4412?
 

wanderinthru

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I'd say Amarillo Off Road would be your best bet for actually having them on hand. North Amarillo Auto Parts deals with a lot of Roundy Rounders too.
Haven't checked lately, but O'Reillys used to carry Holley jets.

Is it a Holly 4412?
Yes sir. I need to find North Amarillo Auto Parts.
 

WFO

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Yes sir. I need to find North Amarillo Auto Parts.
6400 River Road. Take the Loop around to the North to River Road (1st light just past the Dumas Highway) then take a left.

You might call them first. 381-2288
 

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I once stalled a Russian T72 Tank going up a hill. When it started rolling backwards, I panicked and let the clutch out. Luckily, it fired right back up! To my dismay, smoke started pouring out the air cleaner and I now had 6 reverse gears and 1 forward. I shut it down, restarted it and all was back to normal. Later when I told to mechanics about it, they laughed and said yep, diesels can do that. True Story. And yes, I said Russian T72 Battle Tank, perk of my job.
 

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Excessive oil in cylinder and or late timing
 

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