8N Won't Start

[RogerinIowa]

If you put a tablespoon of gas in a couple cylinders and cranked it and it did not fire this would rule out the intake manifold to exhaust crossover as a problem or at least not the cause of your no start.
You said the plugs are new, they are absolutely clean and the gap is 0.025”? Your sure on the gap, please double check.

If you put gas directly in and it started thatCOULD INDICATE A PROBLEM INTERNAL TO THE MANIFOLD.

 

[used red MN]

If you put gas directly in and it started thatCOULD INDICATE A PROBLEM INTERNAL TO THE MANIFOLD.

Roger, in reply 19 number 4. that is what I believe he claims to have done there. I had suggested this before. I assume since he did not report that it ran in my opinion that rules out what I stated reply 20.

 

[Roger in Iowa]

Okay.

 

[Jim L WA]

Bill, I've been following your saga since the beginning. Have you taken a good look at the inside of the distributor cap? If it has carbon tracks, the spark will jump across to the cylinder that isn't under compression.

 

[Bill Tattersall]

Okay.

As I reported in 19, the gas in the cylinders did not work. I want to thank everyone who took the time to offer suggestions. Unfortunately, I'm still stuck. I'm ready to put it aside for a while. Luckily I have another tractor I can use.

 

[old]

As I reported in 19, the gas in the cylinders did not work. I want to thank everyone who took the time to offer suggestions. Unfortunately, I'm still stuck. I'm ready to put it aside for a while. Luckily I have another tractor I can use.

This is not a fun thing to do but it is a way to rule out a bad distributor cap. Hold on to the cap while trying to start it. If you get zapped then the cap is bad

 

[HCooke]

If he has good spark, the problem is not in the distributor. If this were my problem, I would switch a carb from a known running tractor to rule out a problem in the carb. I realize that not every one has the luxury of more than one N. I keep a spare carb on the shelf. It is not for sale but I would loan it to the poster to use a test. Need to pay shipping both ways.

 

[Bill Tattersall]

If he has good spark, the problem is not in the distributor. If this were my problem, I would switch a carb from a known running tractor to rule out a problem in the carb. I realize that not every one has the luxury of more than one N. I keep a spare carb on the shelf. It is not for sale but I would loan it to the poster to use a test. Need to pay shipping both ways.

What a wonderful offer. Despite my less than good mechanical skills, I have leaned toward the carb all along. I would like to take you up on your offer. How can we coordinate?

 

[HCooke]

Send me an email at [email protected]

 

[used red MN]

Bill, I've been following your saga since the beginning. Have you taken a good look at the inside of the distributor cap? If it has carbon tracks, the spark will jump across to the cylinder that isn't under compression.

Jim, I like your theory but I would think that would not keep it from firing on all cylinders. It could but the odds against it are quite high. Next I would have you check the timing with the engine off on number one cylinder and a test light on the distributor terminal of the coil. Then see exactly where the crankshaft/piston is when the points open, that is when the coil fires. Then next would be checking the cam timing by checking it on over lap on number 4 cylinder. Not sure if you can see the valves good enough through the spark plug hole to do this, may have to pull of the tappet cover. On number 4 cylinder when the exhaust valve is closing the intake valve will begin to open. When they are both open the same amount the engine should be on TDC of number one compression or within 2 or 3 degrees on either side. If it isn’t your cam is out of time. I am not sure how far it can be out and still have the cylinders show good compression as yours are. If Mr. Cooke has the miracle cure, I would ask that you please stop back by and let us know. Best of luck with it!

 

[used red MN]

In my opinion as I wrote in reply 20 dumping the gas in the plug holes and immediately trying to start it without it resulting in those cylinders firing rules out the carb and fuel delivery. You can swap around the carbs if you want, I will be quite surprised if the results prove to solve his problem.

 

[Eman85]

When was the last time it ran? Somewhere something is getting overlooked or there's an assumption here that's throwing the diagnosis off.
My N hasn't seen 110 psi of compression probably since Reagan was President and it starts every time. I had one N that was a hair puller and it was bad gas but you've eliminated that. I've started motors with no carburetor on them, just spraying choke cleaner in the intake.

 

[used red MN]

I don’t know if it is uncommon or not to have 110 psi on one of those engines. Not backed up with real solid evidence, but I think cylinder compression can be raised by an out of time cam.

 

[Roger in Iowa]

Hi All,

I have checked this so far:
1. Steady flow of gas from the port on the bottom of the float bowl
2. Good spark at the plugs; hot spark across 1/4" on my spark gap tester
3. 110+ compression on all cylinders

When I crank the engine it makes no effort to start. If I take the air cleaner hose off, there is gas running out of the carb. Then I pull the plugs; they are totally dry. This makes no sense to me, What am I missing. Thanks for any thoughts.

Compression and spark verified per all previous threads. Has timing been verified?? Distributor gear jumped ??

 

[Bill Tattersall]

I don’t know if it is uncommon or not to have 110 psi on one of those engines. Not backed up with real solid evidence, but I think cylinder compression can be raised by an out of time cam.

My gauge was off by 10; the needle was not zeroed. Compression was still above 100 on all 4. Felt Compression on no. 1 at the same time I had spark.

 

[Roger in Iowa]

My gauge was off by 10; the needle was not zeroed. Compression was still above 100 on all 4. Felt Compression on no. 1 at the same time I had spark.

There should be a timing hole on right side of flywheel housing has a tab held by a screw.
With key on out of gear rotating distributor with retaining bolt loosened , number one plug at radiator should spark.

 

[used red MN]

There should be a timing hole on right side of flywheel housing has a tab held by a screw.
With key on out of gear rotating distributor with retaining bolt loosened , number one plug at radiator should spark.

What Roger is telling you in reply 36 is basically what I suggested in the the first part of reply 30. I just don’t make a habit of telling someone to loosen their engines’s distributor and crank around on it when that they claim it hasn’t been touched since it last ran. In my method the test light tells you where your at and the setting of the distributor is not disturbed. Although feeling for compression and seeing spark leaves a lot of room for error. The piston pushes pressure for somewhere short of 180 degrees of the crank rotation. Maybe it is firing way too early, have you ever checked the mechanical advance to see if it is free? Of course advanced timing usually will make it kick-back against the starter.

 

[soaked]

Agree, check static timing.
If distributor clamp bolt loosens up, the housing may turn CCW, and "self retard."

Also, the camshaft has a pressed on gear that drives the dist. Others have had their's slip.( so timing changes)

Points should just break open, as flywheel is pried up with a screwdriver, at 4° BTDC mark.
If yours has slipped below 0° TDC mark, turn dist clockwise until points just open at 4°.
(Can also use a meter to see when reading goes to infinite resistance.)
Static timing is described on page 96 in 52 owners manual.

 

[Bill Tattersall]

Agree, check static timing.
If distributor clamp bolt loosens up, the housing may turn CCW, and "self retard."

Also, the camshaft has a pressed on gear that drives the dist. Others have had their's slip.( so timing changes)

Points should just break open, as flywheel is pried up with a screwdriver, at 4° BTDC mark.
If yours has slipped below 0° TDC mark, turn dist clockwise until points just open at 4°.
(Can also use a meter to see when reading goes to infinite resistance.)
Static timing is described on page 96 in 52 owners manual.

Checking timing as you suggest this AM. My flywheel is marked a 0 and 5.

 

[Bill Tattersall]

I noticed that the shop manual describes the flywheel as having 2 sets of timing marks, 180 degrees apart, Does it matter which set I use to set the timing?