tractor spitting/sputtering question

on our IH 444 gas (in family since new in 1969, was grandpas) it spits and sputters pretty much all the time. the carb & fuel system has been gone thru and most/all of the ignition has as well.

I was wondering if i have a bit of a Cam issue. would worn cam lobes cause spitting and sputtering?

the tach doesn't work (hasn't in years) and it has a gazzilion hours on it as grandpa used if for everything (active dairy farm for 20 years of the tractor's life) but he wasn't a mechanic and was a bit frugal (bordering on cheap) so things didn't get the attention they probably should have including the oil changes. plus before he went into the nursing home it sat quite a bit and used rather rarely and my FIL and Uncle inlaw didn't give it any maintenance either so it could have been a bit sludged up and maybe the cam wasn't getting oil?

no strange noises or knocking. oil pressure light only and it goes off right away once fired up.

THanks

Just because something has been "gone through" does not mean it's fixed. This is not an insult to you or your capabilities. Mistakes happen. Things are missed. It might be worth one more trip through the carburetor.

Also, "most" of the ignition system? What hasn't been changed?

Have you done a compression check?

Could it be a hard miss? Have you tried pulling one spark plug wire off at a time to see if it makes any difference in how it runs?

Remove the distributor cap and spray with WD40 to get rid of any moisture. Dry thoroughly.

Turn the main mixture adjustment on the carburetor out 1/4 turn at a time and see if it helps. If not, put back where it was.

A worn (flat lobe) on a cam will cause a rhythmic (as opposed to a random) backfire through the carb, less at idle, worse the more the throttle is open.

But, you say it's been neglected, so good chance the valve lash has not been properly set. That needs to be checked if it hasn't already. While the cover is off, inspect the valve train carefully for broken springs, bent pushrods, and you can visually see that each valve is opening equally. If heavily carboned, clean it up, but be careful not to dislodge carbon and let it fall into the crankcase. Scrape and vacuum it out, don't try to blow it out. If the gas tank has to come off, dump and rinse it out with some E85 gas.

Once the valves are set, run a compression test. Look for differences between cylinders, 10% is a good number to shoot for.

I would then revisit the ignition system, especially if it ever backfires out the exhaust (symptom of raw gas getting in the exhaust). All ignition components are now aftermarket and questionable quality. Very common to get bad or mis boxed parts new out of the box. Condensers are especially troublesome, if you have an old one, try it, it may be better than a new one. Check the distributor shaft for side play, any wear in the shaft bushings and the points will not stay set.

Take a fuel sample from the carb drain plug. If contaminated, so is the inside of the carb and the tank (unless you already cleaned it). Usually, the carb can be eased apart and cleaned without having to buy gaskets or parts. While apart check the float level, and check for fuel inside the pontoons, shake and listen.

For best results, do these things one at a time. You don't want to multiply problems or not know what fixed it. A shop manual would be a valuable investment!

Well u just confirmed it needs a valve adjustment and a compression check. Once u do that confirm back on your results. Check your valve clearance on each cyl. On TDC and even record it. If there is a tight valve that will be god and no good. Also watch your valves opening while cranking the engine over. If one is hardly opening and you have a large clearance that is a worn cam lob. A major tune up always includes valve adjustment and a compression check. Just replacing plugs or points your still in the dark. Just like going to the doctor when u have a sputter or miss. They check your heart and do blood checks. Just throwing a bottle of pills at you and saying try these is no guarantee you will run better. You have to get to the heart of the problem.

Suggest you try doing a intake vacuum test reading . Normal is 18 to 21 in hg with steady gage needle . might have intake leakage ,valves , carburetor , timing , intake gaskets leak, carburetor gasket leak. Carburetor shaft wear. lots things .

Does it ever clear up if you run it hard, for a while? My 2424 is very similar, and it has always been extremely cold-blooded, even after a carb rebuild. I have to run it with the choke part way out for probably 15-20 minutes or it will stall under load. Once it warms up though, its fine the rest of the day. Its been like this since I bought it in 1988.

It is somewhat better in the winter if I plug in the block heater for a few hours.

Tim

If he has an MS carb, the pontoons are phenolic and you cannot shake to determine if they are okay. They do become gas water logged and require replacement but should not be his problem.

Did ignition gone through include a condenser? and was that in the attempt to fix the poor operation? Jim

Thanks for the replies

Lots of things to check on.

Now I just need a round to it

Thanks.