McCormick-Deering 10-20 runs but I can't hand crank start it

Hi guys,

Ok, you know my tractor well by now! I can start it easy by pulling it but I have been unsuccessful at hand crank starting it.

Tonight I confirmed that I have spark in each plug in the correct firing order. I had all of the plugs out and cranked the motor (putting the pawl down each time) and watching each plug. My spark seems fine, not the biggest spark I have ever seem but it appears adequate.

Prior to that I had already primed the motor and tried firing it. I pulled the #1 plug and had my wife watch for the spark. She confirmed the spark and we checked the #1 piston at TDC or just past TDC. I thought I would just crank the motor and see how many 1/2 cranks it took to get back to the #1 plug.

Wouldn't you know it that the motor fired and ran about 3 seconds before dying. This is the most I have gotten out of the tractor by hand cranking it since we fired the motor the first day. Normally I do not seem to get any type of pop or ignition out of the piston.

What am I missing?? I know now to make sure the pawl is down each time. I put some priming fuel in (about 2-3 tablespoons). I get the motor to where the pawl can engage and then reset the crank to the bottom of the turn and pull straight up and let go at the top of the crank turn making sure to stay clear of the crank. The pawl is usually at the next notch in rotation but doesn't always go in the notch automatically, I just push it down and get ready for the next crank.

Any help would be greatly appreciated. I want to get the starting down so I can get the hood back on and secure and get this thing out and get it driving. It isn't as much fun to get the Kubota out and drag start it.

Thanks,
Dave

Dave,To start with your paw should not have to be reset unless the motor tries to start{a higher rpm than cranking}.Next your choke must work and all the linkage from the air breather must be fitted tight,becaues your moving gas quite aways.Third your float is critical in the carb,And fourth you need to play a little with your timing to find a sweet spot where it will start easy and run smooth when your timming lever is in the down position,these old tractors are a pain in the butt,but when its right it will start the first crank or two

jimmy

I don't know much about hand crank starting, but it sounds like you're putting too much fuel in when you prime it. 3 tablespoons is an awful lot of fuel.

I may show my ignorance here but, does the carburetor have a choke? Rather than spooning fuel in, you might want to set the choke for a couple of pulls to prime the engine with a proper amount of atomized fuel that will fire off much more readily.

When I start the old chain saw, I set the choke and pull until it pops, then release the choke. It always starts and runs on the next pull. That might work for you here, as I've watched a few videos of people hand-starting tractors, and they do the same thing.

That does seem like a lot of priming fuel.

Actually, it shouldn't even need it since you've had it running recently, and you're running gas, so no worries about kerosene in the carb, but those carbs will want one or two half-cranks of choke, then no choke.

You have the original governor, if I remember your video correctly; if so the throttle lever controls the carb directly except at rated RPMs, so the throttle about half too is a good place to try.

Do you have the priming tubes closed? Even without the rings seated yet (I think you have new sleeves and rings, and the head reworked), I doubt this is your problem, but does it have suction [if you have good compression, barring a bad manifold gasket etc, you probably have suction]?

Else, maybe the carb is plugged, but these don't have really fancy orifices.

Do you have a hot blue spark to your plugs when hand cranking? If its a yellow spark your coil may be weak. Hal

Dave
IMHO, James has found most of the problem. The impulse pawl needs to catch & snap for each plug at cranking speed. A mag needs that quick spin when the impulse releases & lets the wound-up spring flip it over & generate the spark.
Also, in case it accidently tries to fire without the impulse delay, it will kick & tear your fingers off or break your arm quicker than you can say "oh shucky darn, wish I hadn't done that".
Get the impulse working first, them bettcha a dollar to a donut, she'll fire right up.
Side note- My Dad farmed with 10-20, 15-30, & regular. Had local "expert" set the timing, could spin each with right hand, never had one "kick".
HTH
Willie

We had the motor man come out and fire the motor. He checked the position of the points and used a channel lock pliers to rotate the shaft of the mag until it was in the right position and then tighten up the bolts from the mag to the motor side.

He pushed the pawl in each time for us to crank it. The pawl on my mag doesn't always catch the little notch each time so I push it down prior to each crank.

I confirmed that I got a spark each time I had the pawl down and got the impulse to spin and throw the spark. The motor guy also timed it so that the spark hits at just past TDC. He told me he has never had a backfire (or a broken arm) in 30 years of working on them. He is big enough to believe!

This was a very expensive magneto rebuild by a professional.........however, I will check the color of the spark. It seemed ok but not an explosive amount of spark.

The old motor man told me it is next to impossible to flood these old motors and I was just doing what he was showing me. I will try less. The carb was also rebuilt by a professional but I did have a few leaks so I was draining the carb each time I was done playing with the tractor. All gaskets are new and seem tight so I don't think I have any leaks.

Yes! I have lots of compression! New sleeves, pistons and rings. This thing is tough to crank against compression.

what if my pawl kinda bounces up after the first crank and doesn't fully engage the next notch? Can Does it only need to catch the impulse once? My motor guy held it down for us while we crank started it that first day.

My choke is good but I'm not exactly sure if the float is working right. Since the motor fired and ran for a few seconds with an empty carb and the fuel line not hooked up, I guess I was just trying to isolate that my timing wasn't set right or my priming wasn't correct to even get a pop or partial fire while cranking. Fuel while running seems to be fine.

The motor guy timed the tractor and we drove it around. He made one slight change that I didn't see but he made an adjustment on the timimg rod so that we could ground the mag to kill the motor. After that change we couldn't had crank the motor that day BUT we didn't try much since we were chasing a clutch problem.

I will try less fuel, check the color/amount of spark and try again.

thanks,
dave

I wonder if they install a new coil? Some of these tractors are over 80 years old. We had a 1926 10-20 that was bought before I was born. Our neighbor had a 15-030 that he only used for belt work. Hal

Dave, that's the rebuilt [Mainely Magnetos, IIRC] mag isn't it? If so, it very likely has a new coil or at least verified.

The one I got from Marks was a bit sticky in the impulse from paint, but I gave it a few drops of light oil right on the impulse [not sure about any other shops, but Mark recommends NO oil in the mag oil ports as he gives the bearings a "permenant" grease making a little oil worthless, and more, just plain messy] and worked it a little while mounted in the vice.

(quoted from post at 10:33:16 04/18/09)
Dave, that's the rebuilt [Mainely Magnetos, IIRC] mag isn't it? If so, it very likely has a new coil or at least verified.

The one I got from Marks was a bit sticky in the impulse from paint, but I gave it a few drops of light oil right on the impulse [not sure about any other shops, but Mark recommends NO oil in the mag oil ports as he gives the bearings a "permenant" grease making a little oil worthless, and more, just plain messy] and worked it a little while mounted in the vice.

Click to expand...

Guess, you already noted the rebuilt mag earlier in this thread! They didn't put too weak of a spring in the trip lever or something? It has to catch everytime you pull on that crank - it won't hurt if you have to reset it each time, but it just isn't right - not to mention, the one time everything is perfect to fire is the one time you forget to reset it and it fires.....the wrong direction! Murphy's Law!

I don't think you are flooding it as neither the priming tubes or R style carb really vaporize the gas, but the 3 tablespoons in each just seemed excessive. Could pull a couple plugs out and see if they're wet. With gas in the priming tubes, and compression, the only thing it needs is spark; maybe you're impulse isn't right.

The murphy's law is exactly right. I have spun it a few time without the pawl in. You look down and just go shuuuucks.

The plugs are not wet but I will cut back on the fuel amount.

Next I am going to check the color of the spark on each cylinder and also check that the spark is firing at TDC of each cylinder.

What would be wrong with the impulse if I am getting good spark?

I can put a tougher spring on the pawl to see if that helps. It seems pop up and get out of the way if I get a good crank on it.

Aside from not staying set [assuming for about half {actually, I think less, but certainly noticable} of your crank stroke the magneto side is not turing while the impulse winds up and it releases quick and clean at TDC], if it's putting a good spark at TDC or just after, the mag is probably doing it's job.

Dry plugs, I don't think the problem was in giving it too much fuel. I wonder if it's getting fuel from the carburator. Maybe the choke isn't closing right, or float level is too low. Possible vacuum leak yet at the manifold, carb, or priming tubes, spraying a little ether around the suspect areas while it's running should show any of those except a priming tube leaking right at the head (doubtful).

Just to brainstorm, you are unscrewing [not just turning the lid] the cup to fill the priming tube, and screwing it snug again after priming.

A couple things to try that would at least indicate the carb not giving it gas while starting: put a tsp - Tbs of gas down each priming tube; screw it down, wait maybe 3,4,5 minutes and repeat [better yet, if you have an ether can that will shoot straight enough to get into the tube you can give it a shot of gas and a shot of ether and shouldn't need the wait time between], if that doesn't give a few pops, now spark seems the issue again. Really, with the amount of gas you had down the priming tubes, you should get a couple seconds running without even a carb mounted - I've done that before.

Yes, the pawl stays set and the mag side doesn't more for about 1/2 crank and then lets go and sends the spark as you describe.

Yes, I am unscrewing the priming tube then tightening it down after we prime. Motor guy showed me that trick.

I put a bit of ether down the tube and didn't get the pop I was looking for. waiting for a few minutes after priming might be a good call. I was thinking about that today. Just pouring gas down and not waiting for vapors to form and take the spark could explain why I got a few seconds of run time and it had been 2 hours since I had primed it last.

Yes, I had Mainely Magneetos do the mag. It looks amazing and seems to function well.

That is perplexing! :?

With ether it shouldn't matter, but I know letting the gas have a little time to evaporate can help: one crank to suck it in and one to fire, it should be running.

If ether didn't do it [with the fact the tubes drank 3Tbs of gas I presume they're not plugged at all, so it should have went straight down], that sure implies spark.

But, except the impulse not reingaging, the mag sounds like it's operating right, so then I think the choke or something else in the carb is up to no good. Still wouldn't completely rule out a leak, yet with fuel in the priming tubes not bringing it alive, nothing on the fuel side should be the culprit.

Since that impulse still has the reingaging issue, it's worth a call to Mainely Magneetos anyway, then you can ask too if they know of something overlooked here.

Since it hasn't been given a good workout yet, I doubt the rings are seated, but prevent starting, that seems like a non issue too.

I really need to go check all of the plugs and the timing and reconfirm everything. Tubes are new and confirmed to be free flowing. The only thing that I did not witness was the motor man adjusting the throttle/timing rod so that I could retard the timing to kill the motor. Before that, we hand cranked the motor to start about 4 times. The engine has run about an hour and half total since first fire. How long should I run it to seat the rings?

I will reaaly work with the starting fluid/fuel and spark lever to find the sweet spot. It gets tiring fast when your by yourself!

Thanks for the help,
Dave

When I had the mag set right and and everything else for that matter on my 10-20, I would have to choke it for 4 pulls with mag off to "prime it" then turn on mag and it would fire first pull every time. I never had to use the primer cups at all. My impulse pawl would stay clicking the first few revs of the engine and then it would kick itself off.

The spark advance should ground the mag [at the mag: lever way up, maybe 1:00 facing it] when pulled way to the left, it sure doesn't hurt to trade a bit of motion to be on the safe side of turning it off - this wouldn't affect starting, only potentially a bit late at full operating RPM [where you'll have it to the right].

It'd be interesting to post a question on the best time frame and duration for seating the rings, and general break-in: probably get as many answers as # of members activly posting! :lol:

Probably somewhere between 20minutes and 20hours of light loads
(just driving it around I'm of the mindset of a few light trips around the yard [closer to the 20minutes or maybe an hour], at least one long enough to get some temp [at least 130's like a hot water faucet] in the radiator check it over, then a good load for an hour or two)
then give it a load of 1/2 to 3/4 rated
(plow, disk, thresher [if there are enough people and bundles to run an hour straight], or dyno or power-eater)
and get the radiator up to boiling [on water, might want a gauge if you already mixed antifreeze, no idea though of the right number - say 220 constant?] for an hour or better.

I've heard of just covering the radiator and driving it around good and warm, and even claims that quality rings will seat without working it - but logic to me seems that getting it to a solid operating temp and under load before the sleeves glaze is the best chance for the rings to seat. Of course, I wouldn't need to count toes, and maybe not even complete both hands, for the number of engines I've given new rings - so I'm probably over cautious.

For that first or second crank start every time, there are likely some sweet spots - but for starting a few cranks, unless wayyyy too late (like 45degrees back down the stroke), or early enough to kick (or the mag grounding yet in the start position: not the case if you have spark), you shouldn't need that much prescision there.

Same with priming fuel: I do like the cups to see if the carb is cooperating, else just choke for the first couple cranks (on 'loose' engines, I've often used Bob's trick of "mag off"-"choke on" first 4, choke off-mag on the next one, but seldom over a couple pulls with choke (and not even turning off the mag) with good compression) should be enough if the carb [and, of course, everything esle :lol: ] is cooperating.

Good luck! Hope you have more fun than frustration or fatiqued muscles. 8)

Here is what I did today.

I confirmed nice blue spark on each plug as well as TDC at each spark. My pawl stayed down each time since I wasn't trying to power crank it and over shoot the sweet spot.

Sprayed a tiny spray of starting fluid into each cylinder. Put in the plug hand tightened only. Second crank...fire!! It ran for just a few seconds since I have the fuel line off and carb drained.

On my crank I just started at the bottom and gave a nice pull up. Last time I was giving it a power pull and having the motor turn a quarter crank past where the pawl should have dropped.

Next, I put in fresh fuel into the priming cups. Not more than one cup full. Second or third crank, I think third...fire again for a few seconds.

During all of this, I did advance my timing just a bit from where I had been trying it before. I think I have found the sweet spot so I'm going to mark it and give it a test with full fuel on Wed or Friday.

Thanks for all of the help figuring out that I believe I was giving it way too much fuel for start up.

I'll update on the full test soon.

Dave