801 runs rough when timed

[FarmerBlair]

Hi,

I've been struggling with my 881 gas (6volt) in trying to get run smoothly and hoping someone here has suggestions. It didn't want to start a week ago after having sat for a couple months. It had started to run a little rough and harder to start when last used it.

-- Replaced points and plugs (AL437). Spark plugs were sooty black.
-- Replaced the rotor.

After that, engine started right up, but ran very rough.

-- using timing light, adjusted timing to 4 degrees and 24 degrees at idle and high rpm.

It still ran very rough after that. So I tried adjusting the timing by ear: rotating distributor till it smoothed out. Got it to run much smoother (still sounds off), but now it is way off on the timing. I think pretty far advanced (distributor turned counterclockwise). You can't see the timing marks on the flywheel because it is so far off.

-- adjusting the carb, but that didn't help.
-- removed the air tube between the air cleaner and carb to make sure air constriction wasn't an issue.

I noticed when I shut down the engine for a few minutes, then start it up again, it blows black smoke out the exhaust for the first second or two.

-- closed down the main fuel adjust on the carb (about 2 turns open), but it made no difference on rough running or black smoke.
-- double checked that the rotor lined up with the #1 post on the distributor when #1 cylinder is in compression stroke. Looked ok.

I'm running out of ideas why it is running rough and runs much worse when I have the timing correctly set (via timing light). Runs better (not great) when far advanced. The distributor mechanical advance seemed to be working as the timing marks shift from 4-degrees to about 24-degrees when increasing from idle to max rpm. Could there still be a distributor problem? Crossed my mind the governor could be out of adjustment for some reason, but I wouldn't have thought that would make the engine run rough like it is.

I do have a problem with the generator not charging the battery. After replacing voltage regulator a couple times, I gave up on that and just put a charger on the battery to maintain the battery at the end of the day. Been doing this since last year. I doubt that is related, but thought I'd mention it just in case.

Thanks

 

[Hemmjo]

I struggled to get my 860 running good one spring. Did all of the normal stuff you have done. Turned out the bushing inside the distributor was worn, allowing the shaft to wobble, which affects when the points open, which is what really controls timing.

Take the cap and rotor off. Turn the crank, I used a socket on the crank nut, so the points are just almost ready to open. Then try to wiggle the shaft to see if the bushing lets it move the shaft enough to open the points at the wrong time. IF the bushing or the shaft are worn the cylinders may be firing at different degrees of advance.

Just a possibility. After 65 years, mine wore out.

Put some marks on your flywheel with a Sharpie. Use your timing light to see if all of the cylinders fire at the right spot. 1 and 4 fire at the same spot, 2 and 3 are supposed to fire 180 from that spot.

Lots of frustrating issues are timing related. Worn parts mess with timing.

 

[FarmerBlair]

Thanks Hemmjo. Good ideas. I'll check it out.

 

[Tim PloughNman Daley RIP]

OCT 08-2023
Firing Order right? Find out true root cause problems and solve, don't just guess and give up when results are not solved. Did you replace the points? You were half
way thru a tune-up so is your wiring correct and firing order 1,2,4,3 CW? Don't assume because you have a 6V battery the system is wired correctly for the 6V/POS GRN
setup. Replacing VR's is mistake #1. Battery should be connected to a float charger (Battery Tender Jr.) whenever not running so it maintains a full charge. Just
connecting a trickle charger when you want to start is wrong. What does your CHARGE INDICATOR read at start up? Lamp should come on at first power. Perform a Fuel Flow
Test first with a cold engine. If drain plug passes, leave Carb alone and move on, it ain't a fuel issue. Don't make any carb adjustments until you verify wiring is
correct. Doing multiple things without knowing if old part is defective or not is illogical. You are just grasping at straws at this point. DO: Fuel Test first.
Disconnect battery, get to a shop and tested under load. Go thru entire wiring system verifying continuity and correct wiring per schematic. When buying new parts you
must verify you are getting the correct part numbers. Never assume and never go by what a dealer tells you. Stop replacing components willy-nilly. Start there.

DOES YOUR 881 DASH LOOK LIKE THIS:

DO YOU HAVE THESE MANUALS:

Tim Daley (MI)

 

[Lynn Patrick]

Remember - new parts does not necessarily mean good parts! For instance, I will no longer use your brand of plugs after too many experiences like yours! I use nothing but NGK's & have had 2 of those also bad out of the box.

 

[FarmerBlair]

Hello Tim,

Thanks for the reply. In answer to some of your points below. These are all things I did before my first post (I left out a few from the initial list because I know my post gets too long):

-- yes, I replaced and gapped the points;
-- yes, wiring is correct (plugs 1,2,4,3 CW)
-- the tractor used to run fine, and charge the battery. I never changed the wiring so I assume it is properly wired. I checked for loose, frayed wires and I think it's ok.
-- the trickle charger is setup on the tractor only when not using the tractor. I don't use a charger to help start the tractor. It is disconnected at that point.
-- charge lamp on dash of tractor comes on when turning on the ignition key. But it stays on when the tractor is running indicating that the battery is not charging via generator. I verified this with a voltmeter at the battery when running. I don't know enough about electronics to delve much deeper than that other than to test the generator. It was working briefly at some point last year, but now there is a whine noise coming from the generator, so maybe there is an issue with it. I had tried polarizing multiple times but no joy.
-- I did a fuel flow check on the carb by removing the plug. Fuel flow was good... came running out the opening. It was only after that that I considered checking carb adjustment.
-- the only parts I replaced were what looked worn, like the points. The rotor also had some wear, so I replaced that. And the plugs were heavily carbon fouled. These were extra new parts I had laying around from working on other tractors that I knew I would eventually need.
-- I know there are issues with new parts. I left the existing capacitor in the distributor when replacing points since I hear new ones are often bad. I do have one or two new ones around and maybe I should just replace it to test if could be the problem.
-- I always verify new parts by researching the parts diagrams on New Holland parts store... including anything I hear about or purchase from this website. I don't purchase willy-nilly or take advice from a dealer without doing my own checking to be sure.
-- I have and used the various manuals you portrayed in your pics, including the more detailed shop manual not shown. Most of those manuals don't necessarily go into diagnostic details (i.e. troubleshooting)... except for the SOS which is pretty good in my shop manual, though I found an error there for band adjustment.
-- Yes, my dash looks like the pic you posted.
-- I did not check in detail the wiring or the continuity of each of the wires. Right or wrong, that's not one of the first things I personally do since I know I'm somewhat inept on electrical issues and prefer to rule out the things I can more easily figure out first. When I replaced the voltage regulator a year or two ago, it worked and the battery charged, but that only lasted a short time before it quit again. Probably true there is something bad with the wiring related to battery charging and thought about replacing it all with a new harness at some point when time permits. When I looked in the past, I didn't come across an exact harness for an 881, but maybe any 801 harness would work.
-- I don't think I've grasped at straws as yet, and I don't want to go there.... which is why I check with people here hoping their accumulated experience on this forum could help.

 

[showcrop]

(quoted from post at 09:43:33 10/08/23)
Hello Tim,

Thanks for the reply. In answer to some of your points below. These are all things I did before my first post (I left out a few from the initial list because I know my post gets too long):

-- yes, I replaced and gapped the points;
-- yes, wiring is correct (plugs 1,2,4,3 CW)
-- the tractor used to run fine, and charge the battery. I never changed the wiring so I assume it is properly wired. I checked for loose, frayed wires and I think it's ok.
-- the trickle charger is setup on the tractor only when not using the tractor. I don't use a charger to help start the tractor. It is disconnected at that point.
-- charge lamp on dash of tractor comes on when turning on the ignition key. But it stays on when the tractor is running indicating that the battery is not charging via generator. I verified this with a voltmeter at the battery when running. I don't know enough about electronics to delve much deeper than that other than to test the generator. It was working briefly at some point last year, but now there is a whine noise coming from the generator, so maybe there is an issue with it. I had tried polarizing multiple times but no joy.
-- I did a fuel flow check on the carb by removing the plug. Fuel flow was good... came running out the opening. It was only after that that I considered checking carb adjustment.
-- the only parts I replaced were what looked worn, like the points. The rotor also had some wear, so I replaced that. And the plugs were heavily carbon fouled. These were extra new parts I had laying around from working on other tractors that I knew I would eventually need.
-- I know there are issues with new parts. I left the existing capacitor in the distributor when replacing points since I hear new ones are often bad. I do have one or two new ones around and maybe I should just replace it to test if could be the problem.
-- I always verify new parts by researching the parts diagrams on New Holland parts store... including anything I hear about or purchase from this website. I don't purchase willy-nilly or take advice from a dealer without doing my own checking to be sure.
-- I have and used the various manuals you portrayed in your pics, including the more detailed shop manual not shown. Most of those manuals don't necessarily go into diagnostic details (i.e. troubleshooting)... except for the SOS which is pretty good in my shop manual, though I found an error there for band adjustment.
-- Yes, my dash looks like the pic you posted.
-- I did not check in detail the wiring or the continuity of each of the wires. Right or wrong, that's not one of the first things I personally do since I know I'm somewhat inept on electrical issues and prefer to rule out the things I can more easily figure out first. When I replaced the voltage regulator a year or two ago, it worked and the battery charged, but that only lasted a short time before it quit again. Probably true there is something bad with the wiring related to battery charging and thought about replacing it all with a new harness at some point when time permits. When I looked in the past, I didn't come across an exact harness for an 881, but maybe any 801 harness would work.
-- I don't think I've grasped at straws as yet, and I don't want to go there.... which is why I check with people here hoping their accumulated experience on this forum could help.

What does " Fuel flow was good... came running out the opening." mean to you? Ran out for a half second or a minute?

 

[FarmerBlair]

Hi Showcrop,

I had a feeling someone would ask that! My bad for lack of detail. I measured the flow rate to get a more accurate estimate. After shutting off the fuel valve at the tank, I drained the carb bowl by removing the plug at the bottom of the carb. I then opened up the fuel valve and measured the fuel flow. I placed the measuring container (pictured) under the carb and measured the time to collect some arbitrary volume. In this case, it took 12.4 seconds for 3 oz of fuel to enter the cup. This is a single sampling, so no stats, but I think it gives a rough idea of fuel flow rate. Hopefully this is a good enough or expected flow rate? I was assuming it was ok (my bad) but could be wrong. Is it about what it should be? i didn't consult one of the manuals for this data, if it exists there (I don't recall ever seeing such info), but at least it's flowing.

 

[Sean in PA]

I'm not an expert on those '01 series, but I think I remember others saying that it should fill a pint container in 30 seconds. If yours stayed at the rate that you measured it, it wouldn't fill quite half that in 30 seconds, so it seems a little slow. Anyone out there with a better memory or better numbers please feel free to jump in and correct me.

 

[FarmerBlair]

(quoted from post at 18:19:04 10/08/23) I'm not an expert on those '01 series, but I think I remember others saying that it should fill a pint container in 30 seconds. If yours stayed at the rate that you measured it, it wouldn't fill quite half that in 30 seconds, so it seems a little slow. Anyone out there with a better memory or better numbers please feel free to jump in and correct me.

Thinking now that I didn't open the fuel valve under the tank all the way open when measuring the flow rate. I opened it maybe 3/4 of a turn. I'll try again tomorrow except with the valve screwed open all the way and see if the flow rate is any better. When actually running the tractor, I normally have the fuel valve all the way open.

 

[Eman85]

It never hurts to start at the very beginning when troubleshooting an older piece of equipment. I would first check the compression at each cylinder.

 

[JMOR]

(quoted from post at 20:09:54 10/08/23) Hi Showcrop,

I had a feeling someone would ask that! My bad for lack of detail. I measured the flow rate to get a more accurate estimate. After shutting off the fuel valve at the tank, I drained the carb bowl by removing the plug at the bottom of the carb. I then opened up the fuel valve and measured the fuel flow. I placed the measuring container (pictured) under the carb and measured the time to collect some arbitrary volume. In this case, it took 12.4 seconds for 3 oz of fuel to enter the cup. This is a single sampling, so no stats, but I think it gives a rough idea of fuel flow rate. Hopefully this is a good enough or expected flow rate? I was assuming it was ok (my bad) but could be wrong. Is it about what it should be? i didn't consult one of the manuals for this data, if it exists there (I don't recall ever seeing such info), but at least it's flowing.

ou are in good shape with that flow rate. Rough running is not a symptom of mis-timed engine. That usually shows as overheating or low power, but still runs smoothly.

 

[FarmerBlair]

Thanks JMOR. I didn't make a lot of sense to me that a lower than max fuel flow rate would cause rough running engine. But then I'm not a mechanic.

I measured again the fuel flow rate today, because I realized I did not have the fuel shutoff valve under the tank open all the way (only about 3/4 turn). This time I got only 2 oz in 12 seconds time. I got the same result twice. Kinda strange it is slower all the way open than when I had the shutoff valve more closed.

Now that you mention about overheating, I have had an issue with this tractor getting hot when using it to brush hog, till, etc. I've tried blowing out any chaff from the radiator, checking fluids, etc. Nothing has improved this. I have to stop putting a load on it after maybe 30 minutes of using it to let it cool down when it hits about 220F. Could this be related to the present problem?

Tonight I tried swapping out the condenser. It made no difference. I also tested what would happen if I disconnect each spark plug separately while it is running at a fast idle. When I unplugged cylinder #4, the misfiring/blubbering stopped. When unplugging any other cylinder, the engine ran very poorly and sounded like it would stutter to a stall (but didn't). While just the #4 plug was disconnected I also tried to adjust the timing to see if it would make any difference. It still would run much slower and rougher when adjusting to the proper 4-degrees BTDC. It sounds best when I am closer to 15-degrees BTDC. This is the same thing that I've been seeing, except now with the #4 spark plug disconnected there was no misfiring noise (I'm assuming that is what is happening). Later I can try to create a 3-4 second video and post it so you can hear it.

 

[FarmerBlair]

(quoted from post at 17:17:25 10/07/23)


Hemmjo, I checked out the shaft in the distributor and no wiggle whatsoever! Thanks for the suggestion.

 

[JMOR]

(quoted from post at 19:47:09 10/09/23) Thanks JMOR. I didn't make a lot of sense to me that a lower than max fuel flow rate would cause rough running engine. But then I'm not a mechanic.

I measured again the fuel flow rate today, because I realized I did not have the fuel shutoff valve under the tank open all the way (only about 3/4 turn). This time I got only 2 oz in 12 seconds time. I got the same result twice. Kinda strange it is slower all the way open than when I had the shutoff valve more closed.

Now that you mention about overheating, I have had an issue with this tractor getting hot when using it to brush hog, till, etc. I've tried blowing out any chaff from the radiator, checking fluids, etc. Nothing has improved this. I have to stop putting a load on it after maybe 30 minutes of using it to let it cool down when it hits about 220F. Could this be related to the present problem?

Tonight I tried swapping out the condenser. It made no difference. I also tested what would happen if I disconnect each spark plug separately while it is running at a fast idle. When I unplugged cylinder #4, the misfiring/blubbering stopped. When unplugging any other cylinder, the engine ran very poorly and sounded like it would stutter to a stall (but didn't). While just the #4 plug was disconnected I also tried to adjust the timing to see if it would make any difference. It still would run much slower and rougher when adjusting to the proper 4-degrees BTDC. It sounds best when I am closer to 15-degrees BTDC. This is the same thing that I've been seeing, except now with the #4 spark plug disconnected there was no misfiring noise (I'm assuming that is what is happening). Later I can try to create a 3-4 second video and post it so you can hear it.

oz in 12 sec is still more than it needs

 

[FarmerBlair]

Thanks JMOR.

At least I figured out why it ran with less misfiring after I disconnected the #4 spark plug wire:
First I tried switching the plug wire used for #4 and connected it to the #3 plug (with the other end connected to the #3 port on the distributor). The misfiring didn't carry over with the wire on #3. So I pulled the #4 spark plug and found the side terminal electrode was bent, such that there was almost zero gap. It was also black with soot. This was a new plug with less than an hour on it. I had another used plug around so I installed that. After that, the tractor sounded good.... no misfiring. I must have dropped or somehow damaged that plug before installing it. I know I gapped everything appropriately prior to installing the new plugs.

Ah well.... nice to have that figured out, but still have the original problem with the tractor running smoothly only with the timing far advanced.

 

[Jim L WA]

Hi FarmerBlair, I've been following your post for a couple of days now. As for the sooty plugs and the black smoke, I would be suspicious of the needle and seat not closing due to either dirt or a bad float or something. Then for the timing to be that far off, I would start from scratch. Bring the number one piston close to top dead center on compression stroke (hold a finger in the spark plug hole) and take note of where the rotor is pointing. The plug wire tower on the cap closest, either right on it or just to the left of that point should have the plug wire going to number one plug. Then double check the firing order for the rest of the plugs, 1,2,4 3 ccw. Then set your four degree timing (don't worry about the 24 degrees, you already proved that's working).
Let us know the outcome.

 

[FarmerBlair]

Hi Jim L WA,

Thanks for your post. I went ahead and checked the rotor position when #1 piston is near TDC. The rotor lines up with the #1plug wire, just slightly forward cw to the cap #1 post. The rest of the plug wires are correctly oriented 1,2,4,3 CW (you had a typo with ccw in your prior post). I set the timing to about 4-degrees BTDC at idle, down from where I left at about 15 degrees. Actually, now the engine is sounding okay. Some minimal blubbering at idle, but generally ok. i'm not sure why its better than yesterday, but maybe having running it around a while yesterday helped. I can't get the idle speed down to 400rpm to set the 4-degrees (it's running at 500rpm), so the timing is set slightly ahead at 5-degrees. Seems the governor linkage kicks it up to 500rpm regardless of idle screw set point. I also can't get the max rpm above about 1900rpm, so I didn't hit 24-degrees, but it was close to within a few degrees.

So it's running pretty well now. There is a persistent "stumble" when pulling the throttle quickly to increase rpm, which doesn't happen when I partially pull the choke (or more slowly increase throttle). I tried opening up the main fuel adjust on the carb, but it made no difference. I turned it out to 5 turns see if anything changed, but no difference. This carb was rebuilt a couple years ago. I returned it back to 2.5 turns open. So that's where it's at right now. Hopefully all this also fixed the overheating problem I was having under load. If it was running too far advanced, from what I heard it can result in overheating.

Thanks to everyone for their help!

Btw, here is a pic of what the new plug looks like that I took out of cylinder #1 today. Seems blacker than it should for running only an hour or so, but I don't know. The #4 plug with the bent terminal that I mentioned earlier was a lot worse, but that's probably because it was damaged. Not the case with #1.