IH 454 backfiring though the carburator.

txpoweranger · Feb 5, 2018

My 454 runs fine at low idle and it runs fine at high
idle as soon as I put it under load it backfires
through the carburator, everything is new plugs wires
everything.

old · Feb 5, 2018

Running to lean will cause that as will timing being off a bit or the advance weights in the distributor sticking and not working as it should

DENNIS MIN · Feb 5, 2018

txpwoer,

Sound like a lean condition. Check your carb,

D.

mmfan55 · Feb 5, 2018

I agree with fuel or timing issue.

txpoweranger · Feb 5, 2018

I've checked the timing and it is good and the points are electronic.

sotxbill · Feb 5, 2018

main jet partially plugged making it run lean???

old · Feb 5, 2018

Ah but it is hard to tell if the advance in the distributor is really working unless you can watch if move and or know for sure the weights are not stuck or springs broken. As for electronic that in it self could be the problem and it is going bad

txpoweranger · Feb 5, 2018

Brand new electronic.

txpoweranger · Feb 5, 2018

Brand New electronic.

Patch700 · Feb 5, 2018

What you are describing is something that is common when a lobe starts to go flat on the cam... If it?s getting a good flow of fuel and the timing is good I would remove valve cover and take a look what the rockers are doing while the engine is being rolled over.. IE: are all the rockers moving the same amount? If one or two are not moving as much as the others either a rocker has come out of adjustment or the cams lobe is wiped on that cylinder.

old · Feb 5, 2018

Only thing now days that brand new means is you stand a 50/50 chance it will even work the first time let alone for 10 years. Me I will NEVER replace points in a tractor with electronic ignition matter of fact I have thrown a number of the electronic ignition away and put back in the points system. I have tractor that have not had the distributor touched in over 5 year and sit parked all winter but fire up just fine in the spring

Steve@Advance · Feb 5, 2018

If the backfire is random, or during acceleration, could be too lean.

Try a partial choke, see if that improves it. If so check the fuel supply to the carb, pull the drain plug, should get a steady stream.

If main is adjustable try backing it out 1/4 turn or so.

Check for vacuum leaks.

Could also be retarded timing, advance not working, weak spark. Check each wire at the plug for 1/4" spark.

If the popping is rhythmic, as in a steady backfire every other revolution, gets worse with load and RPM, check for valve problems. Flat cam. bent pushrod, broke spring.

rustred · Feb 5, 2018

if you are backfiring through the carb it is a cam or valve problem.
check the compression and have a look at valve lift. maybe burnt intake valve.
is the distributer cap new?? you may have a carbon track in it.
is that points or electonic system?
a compression check is always required when diagnosing an engine . so very seldom people on here say yes i checked compression and have the results. record the readings for each cyl. crank for 5 good puff's with throttle open and good battery. and report results.

rustyfarmall · Feb 5, 2018

(quoted from post at 16:30:21 02/05/18) Brand new electronic.

I would be very suspicious of that new electronic ignition. Change it back to the points and condensor and see what happens.

Dave from Texas · Feb 6, 2018

I had the same problem and stupid me had the timing order correct for a clock wise rotation but a Ferguson is counter clock wise.

buickanddeere · Feb 6, 2018

. Valve lash or a weak valve spring

txpoweranger · Feb 11, 2018

Found the trouble, the holes in the discharge nozzle were plugged up, runs just fine now.

IH 454 backfiring though the carburator.

txpoweranger

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old

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DENNIS MIN

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mmfan55

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txpoweranger

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sotxbill

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old

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txpoweranger

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Patch700

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old

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Dave from Texas

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