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woobiedmd
05-22-2011, 05:37 PM
I need some help! My 351 Ford was running great until I changed the spark plugs-put in same Autolite 24. Now it's hard to start, runs rough, and won't idle(dies). I pulled each spark plug wire individually to see if one plug was bad/cracked. The back two on each side don't seem to make a difference! If I pull the vacum line off the carb, the RPM's go up and it seems to run better. If I remove the flame arrestor and look down the Holley 4160, I see gas streaming into the back of the carb. What's going on- I'm driving myself nuts!

JimN
05-22-2011, 06:33 PM
I need some help! My 351 Ford was running great until I changed the spark plugs-put in same Autolite 24. Now it's hard to start, runs rough, and won't idle(dies). I pulled each spark plug wire individually to see if one plug was bad/cracked. The back two on each side don't seem to make a difference! If I pull the vacum line off the carb, the RPM's go up and it seems to run better. If I remove the flame arrestor and look down the Holley 4160, I see gas streaming into the back of the carb. What's going on- I'm driving myself nuts!

Check your firing order and your plug wires.

woobiedmd
05-22-2011, 07:16 PM
How do I check the firing order? I checked the resistance on 2 plug wires and they both said about 675 ohms. Is that OK or too high?

woobiedmd
05-22-2011, 08:31 PM
Looked it up and I do have the correct firing order. I'm not sure how to check the wires.

Skipper
05-22-2011, 09:08 PM
Just ensure that they are seated properly on the plugs and the distributor cap.

If the boat was running fine before you replaced the plugs and....
the plug wires are in the proper firing order....
then maybe one of the plug wires is not seated properly

JimN
05-22-2011, 09:30 PM
How do I check the firing order? I checked the resistance on 2 plug wires and they both said about 675 ohms. Is that OK or too high?

The firing order may be cast into the intake manifold. If the plug wires are old, they're due to be replaced, anyway. You may have continuity but that doesn't really matter to high voltage- a spark tester is what needs to be used, not an Ohmmeter.

woobiedmd
05-22-2011, 09:34 PM
I pulled each plug wire one at a time as the engine was running. Pulling 1,2,5,6 made a difference. Pulling 3,4,7,8 didn't make a difference in performance. I checked the resistance of the wires, 1:717 ohms 5:579
6:578
2:677
3:893 7:767
4:880 8:761
The coil to cap wire was 193 ohms. Are these values OK or not? What am I missing?

Table Rocker
05-22-2011, 11:24 PM
Pulling 1,2,5,6 made a difference. Pulling 3,4,7,8 didn't make a difference in performance.I am not familiar with your particular engine, but that looks like problems on one plane of a dual plane manifold. Are you seeing gas in both primaries? Check for vacuum leaks too.

Did you change your wires one at at time, if so you didn't mix anything up.

rjracin240
05-23-2011, 05:16 AM
I need some help! My 351 Ford was running great until I changed the spark plugs-put in same Autolite 24. . If I remove the flame arrestor and look down the Holley 4160, I see gas streaming into the back of the carb. What's going on- I'm driving myself nuts!

Tell us more about what you see with the gas streaming into back of carb. Are you getting a lot of black exhaust smoke. Does it run better at WOT (wide open throttle)?

woobiedmd
05-23-2011, 06:24 AM
I'm running it in the driveway hooked up to a hose. yes, it runs better at 2K than 800RPM. I wouldn't call it black smoke, but it smells heavily of gas.

JimN
05-23-2011, 09:42 AM
I'm running it in the driveway hooked up to a hose. yes, it runs better at 2K than 800RPM. I wouldn't call it black smoke, but it smells heavily of gas.

Pull the plugs on that bank and check for fouling. You may have a bad plug or a wire may have been damaged if they're old (you didn't say how old the wires are).

mayo93prostar
05-23-2011, 10:41 AM
you changed the plugs and presumeably made no other changes to the carb or the wires, cap, and rotor. Therefore, it sounds like you may have damaged a wire so you should replace the wires and if you are going to do that, you should change the cap and rotor too.

JimN
05-23-2011, 10:56 AM
I pulled each plug wire one at a time as the engine was running. Pulling 1,2,5,6 made a difference. Pulling 3,4,7,8 didn't make a difference in performance. I checked the resistance of the wires, 1:717 ohms 5:579
6:578
2:677
3:893 7:767
4:880 8:761
The coil to cap wire was 193 ohms. Are these values OK or not? What am I missing?

Did you remove the cap, to inspect the inside and the rotor? If so, make sure the cap seated properly on the distributor. You said pulling the #1 wire made a difference and 3,4,7 & 8 are on either side of that plug wire, which happens to be right at the hold-down. If the cap isn't seated properly, the rotor won't line up with the inserts in the cap, so you won't have spark to those cylinders.

Again, look on the intake manifold for the firing order- ir should be closer to the distributor than the other end of the engine and may be 13726548

woobiedmd
05-23-2011, 12:57 PM
Thanks Jim. I did not remove the distributor cap or rotor at all. I will check it tonite. Thanks for everyone's input! I appreciate it. I hope to soon put this behind me!

john jones
05-24-2011, 12:26 AM
Did it ever backfire before or after the plug change? Maybe its a bad powervalve on your Holley carb. I had this happen once, wouldn't idle, it would run good with higher rpm, smelled like raw fuel comming from the exhaust

chawk610
05-24-2011, 03:01 PM
The firing order should be on a metal tag just above the starter celenoid. Weird, this sounds like the firing order got messed up... or the timing. It has to have something to do with the plugs / wires... since that is all he messed with I would think.

JimN
05-24-2011, 03:51 PM
Thanks Jim. I did not remove the distributor cap or rotor at all. I will check it tonite. Thanks for everyone's input! I appreciate it. I hope to soon put this behind me!

You never responded to my comment about the age of the plug wires. How old are they?

woobiedmd
05-24-2011, 04:47 PM
I'm not sure of the age of the wires. I've had the boat for three years- no problem. The overlying issue I think is the fuel dripping into the carb. I spoke today to Vince at skidim. He said no fuel should be dripping. He feels the back cylinders are being flooded/fouled because of this. The fuel is from September. I'm going to top off the tank with some 93 octane and see if it helps. Any other suggestions? I'm starting to think it's a fuel, not spark issue because when I disconnect the spark plug wires to the bak four cylinders, it doesn't matter

JimN
05-24-2011, 08:13 PM
I'm not sure of the age of the wires. I've had the boat for three years- no problem. The overlying issue I think is the fuel dripping into the carb. I spoke today to Vince at skidim. He said no fuel should be dripping. He feels the back cylinders are being flooded/fouled because of this. The fuel is from September. I'm going to top off the tank with some 93 octane and see if it helps. Any other suggestions? I'm starting to think it's a fuel, not spark issue because when I disconnect the spark plug wires to the bak four cylinders, it doesn't matter

It would be better to remove some of the fuel and replace it with fresh gas. While you're at it, take a fuel sample first. That way, you won't be starting with really bad gas and diluting the crap. You'd be surprised by what can be found in a gas tank of a boat that was running well.

Did you check the back plugs yet? Pull them and see if they're fouled and if they are, put a tarp or blanket over the gunwales (a blanket that you don't care about) and crank it over with the lanyard off and the throttle wide open. The throttle beong wide open will clear the flooded cylinders and you don't want it to start.

The plug wires are more than 3 years old- we don't know their quality or condition and as I mentioned, a spark test should be done, using a spark intensity tool. It's not that expensive and it would be a good thing to have. If you have an AutoZone near you, see if they have one to loan.

woobiedmd
05-24-2011, 08:36 PM
Jim- I must have to forget to top off the tank befrore I winterized it. I just put 17 gallons of 93 Octane in it and I'm running it now in the driveway at 1200RPM. I still see gas pouring down the back 2 barrels. How long should I let it run and should I periodically run it up to 2K? Ialso put in some gumout carb/injector cleaner(even though it doesn't have fuel injectors) in the tank. Your thoughts?

JimN
05-24-2011, 08:45 PM
Jim- I must have to forget to top off the tank befrore I winterized it. I just put 17 gallons of 93 Octane in it and I'm running it now in the driveway at 1200RPM. I still see gas pouring down the back 2 barrels. How long should I let it run and should I periodically run it up to 2K? Ialso put in some gumout carb/injector cleaner(even though it doesn't have fuel injectors) in the tank. Your thoughts?

Sounds like it needs some carb work.

hoosier skier
05-24-2011, 10:55 PM
Had the same problem with my old Supra , the float on the carb was sticking . Water was in the fuel causing corrosion in the float chamber and the difference in specific gravity causes the float to ride higher . Flush the fuel tank with fresh gas and install a fuel separator with a bleed port to drain the water. Ethanol in todays fuel absorbs moisture at a high rate .

woobiedmd
05-25-2011, 10:37 AM
I have a filter/separator. Changed the filter last year. I took the back bowl off and adjusted the float. I will try it out tonite.

WilliM1940
05-25-2011, 11:16 AM
It sound like the needle valve is being held open either by junk or damage, or your float has sunk, if you know you never had this problem before. If it isn't junk in the needle try lowering the float, but it may be easier if the float is changing bouyancy to just replace it with a new one. Frankly it is overhaul time.

woobiedmd
05-25-2011, 11:21 AM
Sounds on target. Could I just back out the needle all the way and blow it out? I have the rebuild kit but it looks a little scary.

oxberger
05-25-2011, 11:33 AM
The rebuild may look intimidating, but it's not bad, just keep track of your steps and the parts you removed and replaced. I've done it twice and if I can do it anyone can. Good luck and let us know how it turns out.

thatsmrmastercraft
05-25-2011, 03:20 PM
Sounds on target. Could I just back out the needle all the way and blow it out? I have the rebuild kit but it looks a little scary.

Pull the bowl one more time and remove the float and look at the needle and seat for an obstruction.

woobiedmd
05-25-2011, 06:55 PM
I just did it and no luck! Lots of gas pouring into the back 2 barrels. I put a call into national carburators for a rebuild for less than $300. It won't get here until next week so no boating for me this weekend.:(

thatsmrmastercraft
05-26-2011, 01:12 AM
If gas continues to pour into your carb at idle, either your float is sunk or way out of adjustment or there is a problem with the needle and seat not sealing. Not too late to pick up a float and needle and seat locally and try to save the weekend. Are you sure the float level is set correctly?

woobiedmd
05-26-2011, 08:50 AM
I believe so. I spoke to Vince at Skidim, he told me to remove the bowl, turn it upside down and make the float parallel to the bottom. What I did notice was the cardboard gasket was dissolving/crumbling like wet paper. I believe it got sucked in/clogged something. I ordered a rebuilt Holley from National Carb for $230.00. It won't get here until next week but I feel confident that that will make the difference.Tell me about gas in the oil.

JimN
05-26-2011, 09:33 AM
I believe so. I spoke to Vince at Skidim, he told me to remove the bowl, turn it upside down and make the float parallel to the bottom. What I did notice was the cardboard gasket was dissolving/crumbling like wet paper. I believe it got sucked in/clogged something. I ordered a rebuilt Holley from National Carb for $230.00. It won't get here until next week but I feel confident that that will make the difference.Tell me about gas in the oil.

You don't want to run it with gas in the oil. The oil will break down and its ability to lubricate under load will be nil. Oil needs to maintain a film that stays between the surfaces in contact and when the gas dilutes the oil, this film can't be thick enough to do any good. The gas may clear out some gunk that's in there but if you run it with gas in the oil, you'll wear a lot of parts that shouldn't wear. Think cam, lifters, cam, bearings, etc. Also, any small leaks will become large leaks and some gaskets may break loose.

WilliM1940
05-26-2011, 12:19 PM
That mangy gasket and sinking float I really think is an ethanol problem. It eats plastic, and the coating off the nitrophyl float. I have to overhaul once every two years. With ethanol percent slated to increase in gas, the problem is not going to go away even with your new carb. You might as well learn how to overhaul. I doubt if the gasket material let go into the bowl. At the end of the season, dump the fuel out of the carb at layup. Replace the bowl contents with avgas or kerosene, just dump it before the next season.

TLR67
05-26-2011, 02:49 PM
There is a Filter in your Fuel Pump as well... Make sure you check that too...

woobiedmd
05-30-2011, 08:31 AM
I know about the screen going into the carb and the filter on the water/fuel separator prior to the fuel pump- I've never heard of a filter in the actual fuel pump-what gives?

rjracin240
05-30-2011, 08:42 AM
I just did it and no luck! Lots of gas pouring into the back 2 barrels. I put a call into national carburators for a rebuild for less than $300. It won't get here until next week so no boating for me this weekend.:(

Hope you dont get the carb I returned to them, cause it did not run worth a crap on my 88 190.

Been down your path earlier this year. If you bolt your new carb on and it dies instantly when going for the holeshot you got my old carb, send it back and buy a new one.

Advance Auto when you go online had the best deal I could find for a new Holley 4160.

Jerseydave
05-30-2011, 09:21 AM
Hope you get it running good with that new carb.
I've had a lot of power valves go bad on my holley equipped truck in the past.
It does the same thing, drips gas right down the inside of the carb while at idle.

BTW, where do you ski? I'm on the Delaware river in Florence NJ. (I sent you a PM)

woobiedmd
05-30-2011, 05:30 PM
I'm out of Chalfont- near Doylestown. We usually go down to the Bohemia river(upper Chesapeake). I would need your guidance to hit the Delaware- 3 years in a row-bent nonrepairable props, I just installed a depth finder. Now I will know how deep the water is when I hit my next log!

rjracin240
06-01-2011, 09:21 PM
Just curious to know how yor progress is going towards getting your boat up and running?

woobiedmd
06-02-2011, 08:06 PM
Thanks for checking. Still waiting for a rebuilt 4160 from National Carb. Ordered last Thursday, was supposed to ship out yesterday, now shipping "early next week". The guy said the marine section is swamped. I don't mind waiting as long as quality doesn't suffer. I'll keep my fingers crossed and will post with results.

kjohnson
06-03-2011, 01:22 PM
I agree. I had the same problem on an older boat and the float was sticking and causing the engine to flood. Sounds more like a carb problem than a wiring problem.

woobiedmd
06-14-2011, 09:47 PM
Great News! My rebuilt carb from National arrived today (after 2.5 weeks). Bolted it on after dinner and the boat fired up great! No dripping gas into the carb! I changed my oil to get rid of the gas(thanks Jim)! A minor adjustment to the idle setting but she sounded great! Thanks to everyone for your help! Teamtalk has helped tremendously in learning about/repairing MC's.