2N cold start good, hot start bad

First off, I'll admit that after you read the below, you'll likely think I'm jumping the gun on asking this question. Feel free to blow me off and I'll come back later, but the tractor in question lives 40 miles away, and I like to go armed when I go out there.

The 2N I'm looking after starts right up when it's cold, but is really hard to start when it's hot (or warm), i.e., after use. It'll usually start eventually, after some playing around with throttle and choke. Why it should need choke when hot I have no idea, but without choke it never threatens to start.

The most obvious known problem is that it has a leak in the exhaust manifold at the rear, just before it turns down to the exhaust pipe flange. This area has been (badly) welded by previous owner and is leaking again. I've got a new manifold on order. So, I'm guessing we've got less than normal back pressure, but I won't know what else might be going on in that area until I get the manifold off.

I also have not yet done an ignition tune-up (it's next on the list) or even changed fluids on this recently-acquired tractor.

Could I be getting vapor lock? Or is it the manifold an obvious problem that I'm just failing to understand? Or should I just shut up until I've done the basics?

Thanks in advance for your help.

Could be your fuel line it where it gets hot and then vapor locks. Could be the fuel tank vent is plugged up and causing back pressure or suction on the fuel line. Or it could be caused by weak spark

I once had that problem with my 2N. Turned out the coil was bad.
Mr. Bob

I would do the tune up. That should help. However it may be an electrical problem. If it still does it after a tune up check the spark the next time it happens. If you have a weak spark you may need to clean all the electrical connections including the battery. Also look at the ballast resister. The resistance of the ballast resister increases when hot. If it is corroded I have seen it make hot starting more difficult then cold starting.

6v or 12v?

It's difficult to vapor lock an N; vacuum lock is more likely, but that's not your problem. I'd do the tune-up; that will probably cure the problem. If not, post back & you will get plenty of help. If you've never done a tune up on a front mount, make sure you let us know.

Regarding the exhaust leak, if the block is badly pitted, (usually around # 4) you will have problems; get out the hi-temp metal epoxy. (VersaChem's exhaust manifold repair, or ThermoSteel, said to be good to 2000 degrees). Clean the area real well with brake cleaner, put a little epoxy on it , put some wax paper over it and bolt down the manifold. After it dries take off the manifold and take a die grinder and clean the epoxy that might squish into the port)

Make sure you put the clamp on correctly; check out tip # 8, below.

Do not try & hold the exhaust pipe against the manifold w/ your hand & tighten the clamp. Get out your floor jack & a block of wood; put the jack under the pipe to hold it tightly against the manifold, then tighten the clamp. (Don't get carried away w/ the jack or you will bend the pipe. Or, overtighten the clamp & snap it in two. BTDT)

If the exhaust pipe flange is bent, you will never get a good seal; check it out.

The nuts are brass, 7/16-20 x 5/8, NAPA part number STX104X, 27 lbs of torque. Studs are 1-5/8 long 7/16-14 lbs. NAPA part number for the stud is 86632. Use washers. If you don’t get them at NAPA, make sure that the stud has an egg-shaped center between the different threads.
50 Tips

6v or 12v?

It's difficult to vapor lock an N; vacuum lock is more likely, but that's not your problem. I'd do the tune-up; that will probably cure the problem. If not, post back & you will get plenty of help. If you've never done a tune up on a front mount, make sure you let us know.

Regarding the exhaust leak, if the block is badly pitted, (usually around # 4) you will have problems; get out the hi-temp metal epoxy. (VersaChem's exhaust manifold repair, or ThermoSteel, said to be good to 2000 degrees). Clean the area real well with brake cleaner, put a little epoxy on it , put some wax paper over it and bolt down the manifold. After it dries take off the manifold and take a die grinder and clean the epoxy that might squish into the port)

Make sure you put the clamp on correctly; check out tip # 8, below.

Do not try & hold the exhaust pipe against the manifold w/ your hand & tighten the clamp. Get out your floor jack & a block of wood; put the jack under the pipe to hold it tightly against the manifold, then tighten the clamp. (Don't get carried away w/ the jack or you will bend the pipe. Or, overtighten the clamp & snap it in two. BTDT)

If the exhaust pipe flange is bent, you will never get a good seal; check it out.

The nuts are brass, 7/16-20 x 5/8, NAPA part number STX104X, 27 lbs of torque. Studs are 1-5/8 long 7/16-14 lbs. NAPA part number for the stud is 86632. Use washers. If you don’t get them at NAPA, make sure that the stud has an egg-shaped center between the different threads.
50 Tips

(quoted from post at 16:30:26 11/16/08) 6v or 12v?

If you've never done a tune up on a front mount, make sure you let us know.

Click to expand...

Thanks, Bruce (and others).

It's 6V, and no, I've never done a tune-up on a front-mount. I did get the tune-up video (and the hydraulic one) and have watched them, and I've got all the parts and the FO-4 manual. Just didn't have time to get to it last time I was up there.

So far, all I've done with the tractor is:

1) Check and charge the battery.
2) Change out the too-small battery cables and put proper ones on. The starter cranks a lot better now!
3) Do a general de-greasing.
4) Replace the missing choke knob.

Oh, I did pull the distributor cap to have a look inside (looked clean as the proverbial whistle), but I put it back.

This week, I expect to replace plugs, wires, points, rotor, condenser and cap, and get a look at the pump after its hot to see why it's not lifting. I rather expect I'll be dropping the pump for a good cleaning, at a minimum, and/or changing the lift cylinder piston. The manifold and associated parts won't be here until late this week, so they'll probably have to wait for next week. Guess I'd better be prepared with some Thermosteel. The die grinder is going to be a problem, though, because there's no power at the site.

(quoted from post at 16:05:31 11/16/08)Also look at the ballast resister. The resistance of the ballast resister increases when hot. If it is corroded I have seen it make hot starting more difficult then cold starting.

Click to expand...

The ballast resistor you mention, is it the part shown below?


Where does this thing live on the tractor? Is it up under the dashboard somewhere? And other than cleaning off corrosion, is there a measurement I can make to tell if it's gone bad?

[b:e889cf55a2][i:e889cf55a2]
wwalkersd;
If that is corroded, replace it. It will be weak anyway, with corrosion on it.
Here is where it lives behind yer dash:


Just buy a new one, then ya don't have to worry about it going out when ya need it.
You can get one here from YT or elsewhere....Your call.

Gary [/i:e889cf55a2][/b:e889cf55a2]

Thanks, Gary. I dunno about a thousand, but that picture is clearer than a lot of words!

I'm guessing Mr. Ford's place didn't put those crimp-on terminals on that wiring harness, though. :wink: Neat job, anyway.

[b:7116cf7e12][i:7116cf7e12]

It wasn't hard to put the crimps on those wires......It was the soldering all those wires to the connectors, that was time consuming.
:lol: :shock: :lol:

Hav fun!!!!!!!

Gary [/i:7116cf7e12][/b:7116cf7e12]

Regarding the ballast resistor, the cold resistance should be .3 ohms. They most commonly break or develop shorts, so wiggle the wires while you're checking it.

Regarding the hydraulics, the most common reasons for it not to lift is failure to engage the PTO lever, expecting it to lift w/ the clutch in, the control rod is loose from the fork, or low fluid. If those aren't the reasons, then take the inspection plate w/ the dipstick off. Move the touch control lever & see if the control rod moves. Then, reach in & follow the control rod all the way down to the fork. If it is, then start the tractor & look inside w/ the tractor running & the PTO engaged to see if you notice oil running from the top cover. If oil is running steadily from the top cover the lift cylinder needs to be rebuilt. If no oil is running down from the top cover, look at the rear of the pump in the oil with the load still on it and see if you notice turbulence in the bottom. (Some movement of oil will be normal with the PTO shaft turning). You could have a weak pressure relief valve which will be detected by turbulence in the oil. If you see turbulence behind the pump, raise the implement as much as possible, TURN THE ENGINE OFF then reach in and feel the end of the pressure relief valve. If it is leaking you might feel the pressure push your finger off of the end. All pressure relief valves that fail the finger test are bad & should be replaced. But, not all pressure relief valves that pass the finger test are good because some can have slow leaks.

There are other reasons why the hydraulics don't work, but these are the most common.

I've never seen a tune up video, so I'm not sure what it has to say about a frontmount. The front distributor was designed to come off of the tractor to replace/adjust the points. Remove the wire on the coil, remove the coil bail, remove the distributor cap & take the two bolts off. The base of the distributor has an offset tang & can only go back one way unless you really force it on. Look at how the points & condenser set in the distributor before you start pulling it down! If this is your first time doing it, draw a sketch! Make sure you are using quality parts; the points should have a phenolic rubbing block & not the cheap white plastic crap. Be careful not to ground the tip of the condenser wire to the body of the distributor when you replace the points. Do not break the little copper strip that goes to the points. (If you do, make another out of the old set of points) Also, make sure the condenser wire does not go through the same opening in the distributor that the coil pig tail does. The condenser wire goes the opening on the top right. Look at the old points; are they burned, pitted or mis-aligned? Check the point gap, .015 on all four lobes. Make sure you have the star washers under the screws on the points.

Follow the directions in the I&T FO4 manual for setting the timing after you set the point gap.

Next, with the distributor still off the tractor, install the coil. Look at the pigtail on the coil; is it touching the brass screw inside of the distributor? Don’t trust your eyes; test for continuity from the top of the coil to the points. If you do not have continuity, stretch the pigtail a bit until you do. (some people would rather put a small washer under the brass screw) Look at the little tab opposite of the pigtail; bend it a bit also to insure that it will contact the distributor cap. At this point, I just put the distributor, coil & cap all back on the tractor as a unit (it helps to loosen the fan belt). The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.
50 Tips

Thanks, Bruce. I had actually already copied your points/coil/distributor lesson from another thread, but now I've copied your hydraulic tips, too, which will come in handy. As I mentioned in a thread on that subject, the lift works when cold but not when hot (just like the ignition, hmm. ). I've already been through 3 of the 4 most common reasons, and I assume it wouldn't work at all if the control rod is loose. Time to open 'er up. I'm just waiting on a new gasket for the inspection plate to arrive.

The tune-up video is sold on YT, and is from the same folks that do the hydraulic repair video.

If my 600 stalls out while baling hay it has to be choked to start.Dont get stuck with the idea that a hot engine dosent need to be choked.My 13 hp Honda engine on the saw mill has to be choked if its shut down for just a few minutes.My chain saw acts the same way.Trying to start an engine with a closed throttle will give you much trouble.You have to know your engine.

Well, I got the tune-up done today: new plugs, plug wires, points, cap, and condenser. Would've been a new rotor, but the new one wouldn't fit fully onto the distributor shaft, and upon examination had a visibly smaller hole. Did the distributor shaft diameter change between the 9N/2N and the 8N? I'm wondering if perhaps my 2N has an 8N distributor, and that's why the rotor wouldn't fit.

While the tune-up noticeably improved the cold starting and idling, I ran out of daylight before I could run it long enough to evaluate the hot starting or check the hydraulics.

None of the old ignition parts looked noticeably bad, but I did note that the spark plugs were of a different heat range than the new ones, i.e., they had a much longer center electrode body. I neglected to note the part number, however. The tune-up kit was purchased from YT.

Thanks again for all your help, everybody.