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Discussion Starter · #1 ·
My Dad has an old 9n (might be a 2n, I don't have the serial number), it is an early 40's.
I got the tractor from Dad and it hung out in my shop for 2 years. During that time I tore it down. The engine is the flathead 4cylinder. I had the head planed (it was banana shaped) then repaired the farthest rear/right head bolt hole by threading it and putting in 2 heli-coil inserts. On the bottom end I replaced all bearings (rods/mains) and cotter pins, it has great oil pressure even by cranking it over. Oh, I replaced the oil pump with a used unit from Biewer Tractor in Barnesville MN because the original one had 'galled' the backing plate so badly that it would not pump oil any longer (this was before the bearings were replaced). I also replaced the pistons (after having them cleaned at a machine shop). The spark plugs, coil, points and condensor are all new. It has good spark. It seems like it has good compression, I am assuming that these older tractors (flat head 4cyl) have fairly low compression (I didn't test it). I've taken the timing cover off to ensure the timing was set correctly, and according to the manual that I have it is. And the distributor can only be installed one way so that is a no brainer. I tried several carburators including the one off of my CoOp which was a perfectly functioning carb at the time.

After 2 years and about $400 out of pocket I loaded the tractor back on a trailer and hauled it back to Dad's house. Where he immediately told me that it was a vacuum problem since the intake/exhaust manifold had 'burned through'. So he ordered up a new one and tried a completely different carburator and he still hasn't had any success getting it started.

So here we sit.. lots of parts in the motor but no working Tractor. Anybody got a suggestion to try? What should the actual compression be on this tractor (when using a gauge)

thanks in advance,
-ron
 

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Discussion Starter · #3 ·
The tractor is a 6v system with new battery
Also tried it with a 12v (for faster cranking) in conjunction with a resisterblock for ignition system (disconnected all other electronics)

Fuel does flow to the carb. And to date there have been 3 different carbs (that I know of) on the tractor. With 2 of those being off of working tractors so we knew they were in working order.

Will pop and sputter with starting fluid.

When you hold you hand over the carb (as in to manually choke it) there seems to be plenty of vacuum (unquantified in/hg of vacuum, no gauge) and it will occassionally backfire and shoot fire out of the carb.

I've checked and rechecked the timing. And when I thought I knew I had checked it enough I had a friend of mine come over and recheck it just incase I was getting 'tunnel vision' I thought a new set of eyes would work better.
 

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Discussion Starter · #5 ·
Normally I'd agree, especially since I've been known to put in a (car/truck) V8 distributor at 180° out of phase. I more than triple checked it, and when it got to Dad's house he and his cousin (both over 60) checked and rechecked it so I'd have thought that one of us would catch that by now.

Where the wires plug onto the distributor it is nearly impossible to get the firing order wrong because they come out of the tube at specific intervals. When I checked it, i had my book out and I would 'tug' on each wire individually while the other 3 were taped to the tube so they couldn't slide. And that was how I determined the distrubutor end of the wires when I double checked it.

I'll have Dad recheck it, I might be going that way this weekend for a rodeo, I will print out your provided image and recheck it myself if possible.

You don't happen to know what the cranking compression should be on this tractor do you?

Thanks again
-ron
 

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Old Guy With Old Toys
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Compression is supposed to be 90 psi. If your finger gets blown out of the plug hole it has enough to run, all else being good. I agree with Ken that firing order, plugs are possibly not right.

While you have the plugs out hold a plug wire close to a head bolt and look for a good blue steady spark.
 

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Remember the rotor turns counterclockwise when looking at the cap. #1 top left #2 bottom left #4 bottom right and #3 top right.

I am not sure on the compression..I believe 95, but don't quote me.

I will look further.
 

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Discussion Starter · #8 ·
The compression will push your finger meaning that when it comes up on compression it will push pressure past your fingertip, which I always did with the power to the coil unhooked because...

Spark is good
In the daylight in the shop with the lights on you can still se it shooting from all 4 plugs (plugs are new btw)

I have to older brothers and their favorite game when working on small engines (lawnmowers/motorcycles) was.. "have the younger brother hold the spark plug while I rotate the motor" (that's a lesson you only need once)

thanks again,
-ron
 

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It does sound like an ignition problem. You have checked to be sure the cam is properly timed to the crank by looking at the gears from the way I understood your post. It's been a lot of years since I was inside one of those engines but IIRC the gear on the crank was held by a key. Could this have sheared and created your problem? Likewise the cam gear. I just don't remember how that's all put together.

I did one time see a twisted camshaft in a Chrysler Industrial engine in a combine. That was a tricky one to find.

You may have to pull the valve cover off the side of the engine and watch the function of the valves in relation to piston position. I'm assuming you have checked the condition of and clearance on the valves and that they are all going up and down. A worn or flat camshaft can give these kinds of problems as well.

As many people as have looked at this it's probably not one of the normal things. One thing that does puzzle me is why will it backfire thru the carb with starting fluid and not with gas. If you are able to get the plugs wet with gas by choking it then you should get some kind of fire.

A thought just occurred! Have you checked the exhaust to be sure it's not plugged solid or nearly so?

Keep us advised on this, it's a puzzler.

Mike
 

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Old Guy With Old Toys
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I would not suggest anyone try the procedure due to the risk of fire but I have poured a teaspoon of gasoline down each plug hole of a balky stored tractor, reinstall the plugs and watch it start.
 

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Dabbler in rust
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I would not suggest anyone try the procedure due to the risk of fire but I have poured a teaspoon of gasoline down each plug hole of a balky stored tractor, reinstall the plugs and watch it start.
Have you tried "priming" the cylinders with gasoline to see if it's a fuel problem? Common problem with our grain auger engine is the pison becomes to dry from the oil drianing back to the bottom of the case to create enough vaccume to draw enough fuel into the cylinder, and this may be the case with your newly rebuilt engine. A bit of oil down each cylinder to help the rings create a possitve seal might do the trick.
 

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The tractor is a 6v system with new battery
Also tried it with a 12v (for faster cranking) in conjunction with a resisterblock for ignition system (disconnected all other electronics)

Fuel does flow to the carb. And to date there have been 3 different carbs (that I know of) on the tractor. With 2 of those being off of working tractors so we knew they were in working order.

Will pop and sputter with starting fluid.
When you hold you hand over the carb (as in to manually choke it) there seems to be plenty of vacuum (unquantified in/hg of vacuum, no gauge) and it will occassionally backfire and shoot fire out of the carb.

I've checked and rechecked the timing. And when I thought I knew I had checked it enough I had a friend of mine come over and recheck it just incase I was getting 'tunnel vision' I thought a new set of eyes would work better.
I highlighted your quote, where you said it will sputter with starting fluid. I was helping a guy load his 8N and it quit. he said oh no, the first thing I checked was the position of fuel bowl valve. He had it turned all the way out. All the way out is reserve. I turned all the way in and then a couple turns out and it roared to life. There is a seperate screen for reserve. I know this becuase mine was clogged. If you turn fuel bowl valve a couple turns then it is on, all the way out is reserve. It seems odd that you get a response from the tractor when you use starting fluid, To find out if you have fuel flow to carb take the bolt out of the bottom of the carb when you have fuel turned on. Hey I am a newbie at this also. these other guys know a lot more than I do.
 

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OK, let me be the one going out on a limb here, BUT your timing could still be the problem. Some cams were not marked correctly in these old tractors, that is why I always make my own. The best way to be SURE it is correct is to check the position of the valves when the piston is at TDC the valves closed, is your distributor rotor pointing at the correct plug at the correct time?

Bottom line, you have spark, you have fuel, it all has to come together at the right time. IF you are sure it is right try to pull start it.
 

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Discussion Starter · #15 ·
My wife works in a medical field so I did use a syringe and tried gas and oil in small quanities as well as shooting wd-40 down the cylinders in case the valves and/or rings were not fully seating.

When I first started working on it, the tractor wasn't getting any oil pressure when cranking. I pulled the check spring and funneled oil down it to prime the pump.

As for the fuel tank and the position of the petcock. I was using an auxilary tank from an older JD110 mounted up high by the battery box when I was trying to start it and I verified that fuel was going into the carb by pulling the line off the carb and letting it run into a catch can. So the run vs reserve position shouldn't be an issue.

I called Dad over lunch today and asked if he's checked the timing and he swears that it is set according to the diagram above (I'll still double check it next time I go) he also swears that with these old tractors his Dad used to rebuild them and most of the time he'd have to pull start the tractor after rebuild to perform the 'first start' and he's convinced that is what he needs to do.

FWIW, I've run cars off of carb cleaner (short periods works great for troubleshooting EFI) and I had tried that also.

I started typing this up before JohnW last response...
When I had the timing cover off the distributor was coming around to #1 as the #1 cylinder was coming up the cylinder bore. Which is also how I did V8's but you can still get them out of sync if you don't know which valve is opening... (I had the head on the motor already and didn't want to remove it again)

Thanks again,
-ron
 

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quote...I also replaced the pistons (after having them cleaned at a machine shop). ...New rings .? Seems we always had better Luck ..pulling a rebuild with another tractor...than useing the starter...on trying to restart..add a little oil to the cylinders and pull some more...helps to seat the lands..Good luck..:trink40:
 

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Discussion Starter · #17 ·
One of the rear tires (both were filled with liquid) sprung a leak and is flat now so he won't be able to perform a 'pull start' until he figures out if he can fix it with just a new tube or if he has to get a new tire installed (may even need a rim since that calcium chloride causes things to rust so badly).

I don't know anybody who loves throwing parts at a project that may or may not run, so he's not really in a hurry.

-ron
 

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One of the rear tires (both were filled with liquid) sprung a leak and is flat now so he won't be able to perform a 'pull start' until he figures out if he can fix it with just a new tube or if he has to get a new tire installed (may even need a rim since that calcium chloride causes things to rust so badly).

I don't know anybody who loves throwing parts at a project that may or may not run, so he's not really in a hurry.

-ron
If I understood how you verified that the plug wires where run correctly, that is not a very reliable test. The best way to be certain that the wire from the distributor cap is running to the correct spark plug, is to connect an ohm meter or self-powered continuity tester to one of the plug wire ends, and probe each disconnected wire at the coil end of the wires, until it shows continuity. If the tester won't light or lights dimly or you are getting very much resistance, you've got bad wires. I assume you used wire core wire and not carbon core. If you did you should have very little resistance. If you used carbon core replace them, pulling them through the tube probably caused them to separate, and they are not reliable or the right wire for you tractor.
Also be sure to check that the terminal ends for the plugs and coil have not been pull off the end of the wires.
old as my 9n:goodl:
 

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Discussion Starter · #19 ·
We never changed plug wires, they are the ones that were on it when we bought the tractor. I'll call him and have him add new plug wires to his list of things to do. I didn't change them for pretty much exactly the same reason you just stated. I didn't want to be yanking on the boots and potentially separate the ends from the cables. Good call on the Ohm meter I'll take one with me next time I go, I will also recommend that he or my step brother check that out.

Thanks again,
-ron
 

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definetely change plug wires! especially after a full rebuild like you did!
 
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