Reply With QuoteYour carb is junk. Place your bid right here for a new one
Really though, I would look at the timming first. Then if it's good maybe an intake valve problem.
i have a 73 ford 460, i just had my holley rebuilt because i thought it was the cause of my flames shooting out of the carb. i bolted the rebuilt carb on and it still shoots flames out of the carb. i dont know if it is the timing or what. any help would be great!
Your carb is junk. Place your bid right here for a new one
Really though, I would look at the timming first. Then if it's good maybe an intake valve problem.
Flames out the carb = BACK FIRE = Timing.
Q.E.D.
Firing order messed up? Gotta have the wires on the right plugs. We're gonna check it out and set your timing.
The firing order is 15426378. Cylinder #1 is on the front left (passenger) side of the engine (facing the engine). The cylinders are numbered 1-4 left side front to back and 5-8 right side front to back. The cylinder numbers may be cast into the intake manifold where the each runner enters the head. The distributor rotor turns counterclockwise.
Now, time for the leap of faith. Take all of your plug wires off the distributor cap and the plugs. If you don't know how old they are, spring for a new set. Doesn't have to be anything fancy, you can get some colored wires if you want.
OK, now take off the distributor cap and rotor. Check the points gap by bumping the engine over until the contact wear point is exactly on a high point of the eight sided distributor cam. Doesn't matter which one. Put a .017 feeler gauge in the gap.
It should fit with just a bit of drag as it is inserted in the gap without opening the gap any further at all. If it isn't right, loosen the small screw holding down the points slightly and adjust the gap. There is a little slot that you can place a screwdriver in which will allow you to move the points in the small increments necessary to get the gap right. Once you have the gap adjusted properly, retighten the screw. Check the gap one more time to make sure it is correct. Reinstall the rotor.
Take out the cylinder #1 spark plug (left front cylinder, remember?), stick your thumb in the hole tightly, and have someone bump the engine over. When you feel pressure building in the cylinder, both valves are closed and #1 is coming up to what is called TDC, or top dead center. Look at the timing marks on the crank balancer. They should be getting close to being aligned. At this point, turn the crank in the same direction it was moving with a socket and breaker bar on the crank bolt until the pointer and the zero marks are exactly aligned. Reinstall the spark plug.
The rotor will now be pointing to the cylinder #1 wire position. Now drop the distributor cap on the distributor. If the center of the rotor tip is not pointing exactly at the center of a wire receptacle, loosen the distributor hold down bolt just enough so you can adjust it to that position. You'll have to take the cap off a few times and eyeball it to make sure they are lined up. Snug down the bolt so the distributor can be moved with a small effort, but not too loose. The wire receptacle that the rotor tip is pointed at is now the cylinder #1 receptacle.
Install the proper length plug wire in the #1 receptacle that the rotor is pointing to. Route the wire to cylinder #1 and put it on the spark plug. The next wire counterclockwise from #1 will be cylinder #5. Next is #4, then #2, and so on.
Once all of the wires are on correctly installed (check it twice) and the cap is clipped back on, move the distributor about 1/4" clockwise. This will approximate the initial timing setting of 8 degrees BTDC (before top dead center). Get some liquid paper correction fluid and put a little on the timing mark pointer and the 8 degree mark on the crank balancer (makes 'em easier to see in the sun).
Hook up your timing light. The clip on the light goes on the #1 cylinder plug wire, and the other two wires are connected to the battery. Put the coil wire on and start the engine (with the ass end of the boat in the water to provide engine cooling). The idle should be around 600 RPM. If it's not, adjust it.
Point the light at the timing marks. Your goal is to align the pointer and the 8 degree mark. If it is less than 8, move the distributor clockwise. If it is more than 8, counterclockwise. If the idle speed changes noticeably, readjust it to 600 RPM. Once you have the marks aligned, tighten the distributor bolt. Don't go nuts on it either, it doesn't need to be muscled.
Check the alignment and RPM one more time after you tighten the bolt. If the timing has changed, just loosen the bolt and do it again. You just have to be careful not to let the distributor turn while the bolt is being tightened.
Once this is done, shut off the engine and remove the timing light.
Put your cooler in the boat and launch it. Go out and have some fun. Easy, huh? Remember, 99% of the time when you see a jet boat farting and popping across the lake it's because these steps aren't properly followed. Get comfortable and proficient with this procedure and you can graduate on to more complicated stuff.
[ July 22, 2003, 02:51 PM: Message edited by: rrrr ]
Oh and uh take your rebuilt carb back to the shop and have that blown power valve replaced.
HOSS:
Oh and uh take your rebuilt carb back to the shop and have that blown power valve replaced.
Kerny, a backfire will rupture the diaphragm in the power valve. Have it checked out.
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