Guttless M
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Guttless M
My 77 1/2 ton 2-wheeler (351M) starts fine and seems to have plenty of power in park, but as soon as she's in gear all torque is gone. It will spit and sputter and backfire like mad as soon as you give it any load. It sat for a while before I bought it from the 2nd owner and had some old gas in it, but this is rediculess. I did put fresh gas in it when I bought it. It has new plugs, a carb kit, fuel filter, and a new fuel pump. Ignition problem? What should I check next; any ideas? Please help.
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From: Sugar Grove Pa
I used to think my 351M was gutless too until I got the bugs worked out. In my case it was old gas/rust in the tank. I removed the tank, and replaced the sending unit. While I had the sending unit out, I dropped a length of chain in it and rattled it around, then flushed out the tank. Took lots of crud out.
then I replaced all the rubber fuel lines, they have a tendancy to collapse when they are old.
In your case I would also take a look at the coil and plug wires.
And if it is rust in the tank don't be afraid to replace the fuel filter weekly until it clears
then I replaced all the rubber fuel lines, they have a tendancy to collapse when they are old.
In your case I would also take a look at the coil and plug wires.
And if it is rust in the tank don't be afraid to replace the fuel filter weekly until it clears
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Joined: Nov 2006
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From: Simi Valley, CA
Ford fuel tank senders have a plastic mesh filter screen that slides over the end of the pickup tube (exc in-cab fuel senders). By now, it's prolly either collapsed or plugged up.
If replacing the filter, you should also change the float, it's prolly on its last legs, too.
These parts are available from Ford, NAPA, prolly others.
D1AZ-9A011-A .. Filter Screen- 3/8" If buying from a parts store, make SURE you get this size, there another that's 5/16"..it won't fit.
C0AF-9276-A .. Fuel Sender Gasket
C0AZ-9202-B .. Fuel Sender Float
If replacing the filter, you should also change the float, it's prolly on its last legs, too.
These parts are available from Ford, NAPA, prolly others.
D1AZ-9A011-A .. Filter Screen- 3/8" If buying from a parts store, make SURE you get this size, there another that's 5/16"..it won't fit.
C0AF-9276-A .. Fuel Sender Gasket
C0AZ-9202-B .. Fuel Sender Float
Last edited by NumberDummy; Dec 5, 2007 at 11:40 AM.
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Hey, thanks for the info guys. I think I'll start at the tank then, and if that don't help-onto timing.
Backfiring was more-so thru the carb. Cap, rotor, and wires don't look all that bad; but looks can be decieving.
Backfiring was more-so thru the carb. Cap, rotor, and wires don't look all that bad; but looks can be decieving.
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backfiring through the carb the first thing I'd look at would be timing.. overlean mixture, (including bad fuel pump, clogged filter, compressed lines, etc) misadjusted carb, flooding, etc can all cause backfiring but that's usually through the exhaust in my limited experience.
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Originally Posted by ErrorS
backfiring through the carb the first thing I'd look at would be timing.. overlean mixture, (including bad fuel pump, clogged filter, compressed lines, etc) misadjusted carb, flooding, etc can all cause backfiring but that's usually through the exhaust in my limited experience.
Yep, most of the time if your backfring up thru the carb it's timing. So I'd start with the dizzy. You can check the slop in the timing chain by popping off the dizzy cap and turn the crank pulley back and forth to see how much play their is between the rotor moving.
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I would check timing first. Also if you just rebuilt the card I would check for vacuum leaks around the carb. Also check to make sure the throttle valve is operating.
Last edited by 460in503; Dec 5, 2007 at 03:40 PM.
