I've got problems.....

Chance M

Member
Ok, I'm gonna try and get it all in without forgetting.

I've been plagued with carb issues. So, float had a hole, thought I had it beat with a new float. Put it in the carb. I sand blasted my plugs and adjusted my valves prior to the new float. The plugs where extremely carbon filled due to running really rich. The engine ran about the same as it did prior to new float. So I started getting extreme on the needles to see a difference in tune. When I would take the idle mix screw all the way out, the idle would get much smoother. At any rate, I hooked the brush hog up, went out and engaged the pto. Pretty much that is when the miss showed its ugly head and from then on it ran so poor. No power, lots of black smoke and a horrible miss. Would cut anything.

So, I took it to the shop, started trouble shooting, mind you that I have been fighting a fuel leakage from the carb. Since the beginning. Cant get rid of it. It is not the high speed port. It is dropping from up inside the ventury . I think out of the idle port?! Maybe residual fuel from a rich condition, not sure. Has me confused. Gonna purchase a new carb I guess.

So, I pulled the plugs. Major carbon build up again. I think they are fouled. I cleaned the, but it didn't change. I started pulling plug wires off to find a culprit. Number 3 cylinder plug wire made no difference in running. I checked the wire and pulled the plug and fired the engine. The plug made spark, but that's not under compression. I moved that plug to number four cylinder(swapped). Now number four cylinder plug wire off makes no difference in running. So I believe I have fouled plugs.

Can a fouled plug be cleaned and reused? I thought so, but it doesn't seem so. I've ran a lot of gas engines, never a tractor and I've never had a fouled plug so believe it or not, I have no idea what to expect. Will get a new set of plugs tomorrow when I go get my hydraulic hoses made up.

I'm hoping a new carb and set of plugs fixes this. It feels electrical as much as it does fuel related. I suppose the fouled plugs would give me this conclusion. I'm using the Petronix electronic ignition. Could there be an issue with that? Would running to much resistance to my coil be a prob? I don't know if my coill is a 1.5 or 3 ohm unit. I've got a 1.5 ohm resistor in line. So if my coil is a 3 ohm, would another 1.5 make a problem? Gonna buy a multi meter tomorrow as well to check things.

I've put so much time and great effort in restoring this tractor and can't even use it. I'm very heart broke at the moment because of these troubles. I am at wits end with the carb. The float is adjusted properly, the ports and jets cleaned countless times. If I've had the carb apart 20 times I imagine, trying to clean clean clean, adjust this or that. See what or if something was a problem. New is all I know to do now.

So yeah, it started the morning running pretty fair...no load though, To missing and running horrible, now cant rectify with cleaned(but the same) plugs, cleaned carb....nothing changes it now.

I even checked the radiator to see if I could have a blown head gasket. No water in oil.

I'm just gonna start throwing money at it now cuz I have no other ideas at this point.

Could plug wires be and issue. I bought some stuff off eBay. They are the hard wire type( stranded wire inside). Should I get a good quality set at the auto parts store? Like maybe I'm getting a weak sparked is why I'm getting this rich condition no matter what the carb does. Any thoughts at all, plz share.

Thanks,
Chance...
 
(quoted from post at 19:58:47 08/30/15)
What tractor? What type of carb?

An M....sorry bout that.

Not sure what carb...it have the double sided float if that helps.

Newly overhauled.
 
You might not need that resistor. My only experience with Pertronix is on a 656. Pertronix on this 656 was installed by someone other than me and after that installation the tractor started hard cold and not as well as it should hot. The owner ran it this way several years till one day when I was using it I decided to dig into it to find out why it was starting hard. I found the resistor was still being used so I talked to an IH mechanic and he said the resistor is not needed with a Pertronix unit installed. I disconnected the resistor and bypassed around it and solved the hard starting problem. I don't know what kind of a coil it has. It has run fine this way for three years now.

As a side note I could not find a start bypass wire around the resistor. I was told there should be one but there was no bypass wire to be found. The power feed to the coil went through the resistor full time, even in the start cycle.
 
Teething pains are normal and if this is your first experience with 60 year old tractors, be patient. these things, when sorted out, are incredibly strong. I think your needle has a piece of trash under it, or is not seating well, thus allowing excess fuel into the bowl flooding the engine.
With the fuel shut off at the tank, and the bowl off of the carb, lift the float gently with one finger till the needle seats. Now open the tank valve (still holding the float) and if fuel comes out, the needle and seat are not shutting off fuel as intended. If letting down the float immediately allows flow, and it shuts off again when lifted, it is good to go. Sometimes just doing this clears a chip of trash. If it will not shut off the fuel completely, the issue may be the needle being pushed up at an angle. The little tab that lifts the needle must be f;at to the base of the needle. Patience, the end is near. Spark plugs can be cleaned (do not use a wire brush, they leave metallic conductive streaks, Heating with a propane torch, while on a brick, can remove carbon fowling. Heat till the ground electrode is red. Jim
 
Bead blasting plugs to clean them used to be the norm, but it seems, not any more. These days, on my 400 Case, if a plug fouls, might as well toss it and put in a new one. Not sure what changed, the plugs, the gas, or what? Same deal on some old Honda motorcycles I have.
 
Lead and additive fouling on plugs stopped when the lead was removed. Light carbon deposits fromrunning rich are much less radical, and are removable. Especially on new plugs like he is using. Jim
 
I sand blasted(literally used sand) them before this last run. Got less than a half hr run time before they completely fouled out this time...

Im gonna get it Jim.. Ive done a lil research. Beginning think I got a crack or warped surface in the carb. Web can be dangerous. Good info, false info, who knows, haha.

It's got me down though, not gonna lie. Darn tractor! Lol

Thanks for info fellas.

Oh, I ordered a new carb. Now im slinging dinero at it. Like I haven't been kind enough to ole girl already, she wants more....
 
Well don't throw away your old carburetor. If you do like Jim says and get your seat to seal you'll probably have your rich problem fixed. New spark plugs are in order. When you bought you Petronix did you specify 12v? If so, you don't need a resistor.

I'm sure you know the idle adjustment is an air mixture so all the way out is lean. Running smooth all the way out means you are getting too much fuel from the leaking seat. Float level is not too important, but gas running out the carburetor is important and you need to get it to hold.

I've got 11 M's and have never had a new carburetor. I hope it's better than a lot of other new stuff.

Do what Jim says and verify that the seat is holding. Just because you put in a new needle valve does not mean it will hold with trash under it or if it has a defect in the tip or seat ring.
 
(quoted from post at 03:40:31 08/31/15) Well don't throw away your old carburetor. If you do like Jim says and get your seat to seal you'll probably have your rich problem fixed. New spark plugs are in order. When you bought you Petronix did you specify 12v? If so, you don't need a resistor.

I'm sure you know the idle adjustment is an air mixture so all the way out is lean. Running smooth all the way out means you are getting too much fuel from the leaking seat. Float level is not too important, but gas running out the carburetor is important and you need to get it to hold.

I've got 11 M's and have never had a new carburetor. I hope it's better than a lot of other new stuff.


Do what Jim says and verify that the seat is holding. Just because you put in a new needle valve does not mean it will hold with trash under it or if it has a defect in the tip or seat ring.

I've done what Jim said, multiple times. There is no trash. The leak is not coming from where it was before(the high speed jet). It is coming from the top of the carb. I got a light and turned the choke to where I could see the very tip of the main jet. The fuel actually dripping from above. I thought it mighta been the gasket but it is not.

I would send you the carb and let you see for yourself if it wasn't gonna be sent in for core. Ik that it means it's getting to much fuel but i can't rectify it and yes, I sure hope it is a good carb I'm buying Andy. It's remaned by a guy in Cali. He guarantees it, plus I can send the core in for 70.00$ return.

Another thing. When you guys have split your m carbs, there is two jets at the end of the center round portion( the ventury). Is one of them protruding upwards a few mm above the surface? Mine is not, as if it rotted off. But in photos of new carb it is there. Just wondering, may be nothing.

Trust me, I know what your thinking. This guy is an idiot and just blowing cash. But I've been fussing with this carb for two weeks. And tried everything. I hate that I'm buying a new carb and that it has beat me! I'm sick of taking it apart time after time o find nothing. Clean as a pen, good float now, adjusted perfectly. Have cleaned all ports multiple times. When I originally pulled the carb and cleaned the packing from main needle hole, I was using a scratch awl for its sharp point of course. I slipped a couple times(I know) jamming it into the needle seat. I don't know if I hit it hard enough to do damage and if I did a little I still don't think it would effect the tune like this or cause fuel leakage.

And btw, don't just stick your hand up to the intake while its at half throttle, haha.

It says in the pertronix directions that I must use a resistor for the coil. I called them to verify because my meter was to large to read the low ohms. My coil was a new unit from tsc and the guy said likely that my coil was a 1.5 ohm internal and that the resistor included with the alternator was 1.5 which is what I need for four cylinder....a total of 3 ohms resistance....but, I'm gonna get me a small meter today and get it perfect...or make sure it is.

On a side note....I grounded the coil. But if I grab the coil with my hand and touch the negative terminal with my thumb it'll give me a lil shock. Not real strong but it's there. It's grounded very well, why would I get the shock??

I'm possibly thinking of going back to points to see if there is something going on there. A process of elimination. I only want the electronic ignition so I dont have to think about points in the future. I'm usually busy and hate things like that at worst time shutting me down for maintenance when I'm set on go go mode. Prolly shoulda left well enough alone though, haha.
Thanks

Chance
 
Check & make sure you have a good sealing gasket under that seat. Put a barb in the drain with a clear tube on it to see the fuel level.
 
Nobody thinks you're stupid, just frustrated. The tube that sticks up from the bottom half of the carburetor is the idle jet and needs to be there. It feeds it to the main jet to pump idle gas into the engine.

When you say the carburetor leaks gas, is that when sitting with the engine not running?
 
On that 656, did the bypass terminal on starter solenoid have a double wire. Later 656 use a resistance wire between ign switch and the bypass terminal on solenoid. Then plain wire from solenoid to ignition coil. If you have that system on that tractor plus the ballast resistor, you would be running two resistors in series thus low voltage to coil at all times. A possibility.
 
Here's a suggestion that might possibly
help: see if you can find somebody who
is willing to let you borrow their
carburetor for testing purposes. My Dad
and his brother both had an M each, as
well as a JD 70 each. No telling how
many times they were able to isolate a
problem by the process of elimination
using substition. Anybody on here wanna
help out a fellow red tractor fan? Good
luck, Hugh.
 
Chance, You never actually said which model tractor you have.

Is the carburetor iron or aluminum/pot metal. Yes, the tops will warp on the aluminum carbs. I had to carefully flatten the top of a Carter carb on my cousins Super C and then lap the remaining irregularities using specially made lap with a hole in it to accommodate float ears etc. I also had to rebush the butterfly linkage and make a new shaft although some kits have them.

DL
 
No body asked what plugs are you using. These days you have to have a hotter plug than the manual calls for. I know lots of guys prefer autolites to champions but I have been running D21 champions in my letter series tractors for years with no fouling or plug issues. I don't know what the equivalent autolite plug is. Another thought on your leaking carb - have you checked the engine compression. If you have low compression it will start pulling gas and not get it to the engine - leaks out the carb. I haven't followed all your threads - does the tractor start easily or does it need a lot of cranking. All letter series Farmalls will leak gas if you crank them a lot and they don't start.
 
I had the problem of gas dropping down in a case. Turned out to be a bad head gasket. A compression test confirmed it for me. Ran terribly, would pool gas in the carb throat. Quick to check anyhow.
 

Hello fellas,

I got to mow today....I changed the plugs with some brand new ones (auto lite 386). Checked my coil with new meter. The resistor I was using was the one that is made to reduce the voltage to 6 volt if you where still using old parts, haha. I bypassed the resistor and running without 3 ohm diode to coil. Mowed for 4 hrs straight without an issue. It is still running a bit rich from the carb issue but WOW, I'm surprised at the power this guy has(far all M) . I'd say it is close to as strong as my M6800 kubota(63 pto hp)....

How much black/grey smoke should be present at idle and slightly above? How rough should the idle be? I have lots of smoke at idle and it is not smoothest idle that is for sure. Under load it is strong as hell. I have adjusted the needle with no huge change in the idle, without going way out on the idle mixture needle. Which isn't right. I used basically stock needle setting to mow with and when I run from place to place I would lean the needles half turn to make suRe it's not overly rich and fouled plugs again. There is no smoke present when at working pace. It might puff some black when it would bog in the tuff stuff, but that's it.

I'm in love with her again, haha. Now I gotta get my wiring soldered up and sorted, get new carb on it, replace countershaft and liftall seals and I'm settin purty...

Thanks everyone for the info and listening to me whine, haha.

I can't tell Ya'll how tickled I was to do all that hogging today and feeling the power this ole machine had. I didn't live back in the day but it sure felt good using this old iron I brought back from the trash pile. A feeling that can't be replaced I don't think.

The hydraulics are something of a technique to be learned haha. I got it down now.

Peace

Chance
 
Thanks Pete. It makes sense. Someone possibly added the ceramic resistor sometime in the past. I don't know what year this 656 is. Jim
 
(quoted from post at 20:18:27 08/31/15) Thanks Pete. It makes sense. Someone possibly added the ceramic resistor sometime in the past. I don't know what year this 656 is. Jim

Is it possible you're burning oil and it's fouling the plugs?
 
(quoted from post at 17:59:33 09/01/15) The can of the coil is not attached in any way to the wires inside it. Jim

Jim, why would I be getting a jolt from touching the negative terminal on the coil? Maybe I'm losing some juice here or something? What's your thoughts?

Thanks
Chance
 
As stated, the coil internal wiring is not attached to the coil can. The coil when firing can and does produce 150 to 250 volts of AC that pass into and out of the condenser as the magnetic field collapses in the coil. The jolt you feel is that voltage potential between the primary circuit, and ground (the can of the coil) unpleasant it is. Jim
 

Don't know what I'd do without ya Mr. Jim. I'm gonna know a little by the time I get this tractor 100% complete. Thanks

Chance
 

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