8n running rough

[michaelthorne75]

My 8n side mount is running rough. Timing and carb have been inspected. Carb cleaned. I have not got out the timing light yet , but set as close as you can get without it.

It hesitates when throttle is increased. Please help. Thanks in advance.

Also I have a video but can't figure out how to post it.

 

[Royse]

Pull the choke a little bit and try increasing the throttle.
If that helps, I'd still check for good spark.
On an adjustable gap spark tester it should jump a 1/4 inch.
If that checks out good, back the main adjustment needle on
the carb out a 1/4 to 1/2 turn more and see if it helps.
Where do you have that adjustment set now?

 

[michaelthorne75]

I set the carb setting to the book settings. (1 turn out). But even
when I adjust or play with them, it still runs rough. And doesn't want
to stay running at low idle. Has to be at around 700 rpm.

 

[Royse]

Try 1 and 1/2 for the main adjustment and 1/4 to 1/2
for the idle air adjustment. It adjusts air, so in is richer.
The choke test would help here too.

 

[michaelthorne75]

Ok. I'll try that tomorrow. I'm not where the tractor is now. Also it has
a new distributor, could it be something with the timing? Just
confused I guess.

 

[Royse]

Yes, it could have something to do with timing, or weak spark.
Or the distributor itself if new aftermarket.
What were the symptoms before replacing the distributor?

An adjustable gap spark tester is about $8 at our local parts stores
around here if you don't have one. Easy to use to verify spark.
Static timing is easy to set. Advance timing pretty much requires
a timing light and a running tractor, but I don't believe advance
timing is likely to be your issue.

 

[Bruce (VA)]

If it won't idle below 700 rpm, you best try that carb cleaning again.
75 Tips

 

[michaelthorne75]

This is a tractor that I have been restoring for a while. So this is the
first time starting it up. I have started it up a few times , and everyone
, it runs rough. I got a spark checker, and all are sparking. I have set
the timing a few times due to the ring that holds dist down was loose.
One time I set it according to the book and it was way off. Wouldn't
even start. Just backfired. That's why I was wondering about timing.
It wants to shut off when I move throttle up. Have to kinda play with it
to get it to not shut off if you move throttle up slow.
Also something is up with my linkage because it goes from 1000 to
2400 rpm with just two or three notches on the throttle plate. It's a 6
volt also. Just trying to give you some info. Thanks for the help. If
you have an email , I can send a video. If you think that would help.

 

[michaelthorne75]

I think i have a linkage problem. I can get it below 700 with the linkage off the governor but it runs so rough, it don't want to stay running. But I'll check the carb again.

 

[Royse]

To set the timing, pull the spark plugs and the distributor cap.
Roll the engine by hand until you feel compression coming out
of the #1 spark plug hole. Continue until the timing marks read
4 degrees before TDC. Look to see which tower of the distributor
cap the rotor is pointed at. Put the #1 spark plug wire on that
tower and the rest 1-2-4-3 Counter clockwise around it.
That will at least be close enough to start it.
Then time it with your timing light.

If the rotor doesn't point at a tower and you can't turn the
distributor to make it point at one, you may have to pull it and
reposition it so that it will. Then I would make it match the book.
Can't say I've ever had that happen, but I have had the #1 wire
positioned pretty much anywhere around the cap. Didn't matter
as long as the firing order and timing were correct once done.

The linkage problem is probably a separate concern.
That might make it not idle down, but wouldn't make it run rough.
Of course you can't really adjust the idle air accurately until
it does idle down, but that's another story.

 

[michaelthorne75]

Ok. Thanks. I'll recheck the timing with the method you just posted. I
was setting it by pushing the starter. And I think I got it a little too far
before. I'll get back tomorrow afternoon and give update. Thanks for
all your help.

 

[michaelthorne75]

I rechecked timing. It's correct. I even swapped out the plug wires.
It sounds like it's skipping. Could it be the plugs or something in
dist??

Pulling the choke just a little seems to help some.

 

[mrjim]

Have you been able to solve your problem michaelthorne75? I am having the exact same problem. I have not made any carb adjustments yet. It runs pretty good from idle to about 1300 rpms, then gets rough real quick. Just curious what you came up with. Thanks

 

[Hobo,NC]

What is your total timing "I like" 24/25 degrees...

http://www.badasscars.com/index.cfm/page/ptype=product/product_id=76/prd76.htm

 

[michaelthorne75]

No. Not yet. Not sure what the problem is. Prob in the ignition system. I've done several things but no change. Just confused. Thought this would not be this complicated

Runs rough and hesitates when you move throttle up.

 

[michaelthorne75]

Hobo. I had no idea. Not to some like an idiot, but I'm a little
confused. I guess I need to get one of those timing lights. To figure
out this total timing thing.

Have you had this issue before that was fixed by this timing ?

 

[L.Fure]

(quoted from post at 00:26:35 10/26/17) No. Not yet. Not sure what the problem is. Prob in the ignition system. I've done several things but no change. Just confused. Thought this would not be this complicated

Runs rough and hesitates when you move throttle up.

The hesitation is more than likely a carburetor problem. The adjustments are too lean. One cause for not being able to get good results when adjusting the idle mixture screw is an air leak. Use a can of carburetor cleaner to find the air leak with the engine running. Spray it at the carburetor shaft, the point where the carburetor is bolted to the manifold, and around the intake manifold where it attaches to the engine block. My bet is the carburetor shaft has side play in it causing it to suck air in at that point. You'll know when you find the leak, because the rpm's will increase, or smooth out when the spray hits the right spot.

 

[L.Fure]

(quoted from post at 02:53:34 10/24/17)Also something is up with my linkage because it goes from 1000 to 2400 rpm with just two or three notches on the throttle plate.

Your governor may not be set right. Look in the repair manual on how to do this. One other thing could be that someone put too strong, or too short of a spring between the linkage and governor arm.

 

[Hobo,NC]

Inline spark tester use.

Sometimes spark and fuel issues mimic there self it takes a trained ear to tell the difference and then it not 100% reliable.
What does a light tell you (the one you hook in series with a plug wire)

What we don’t know and what it will not tell you is spark health (KV) If you have a good runner with intermittent issues you learn to judge spark health by the color of the light You will have to be the judge.

On a no start it can be used to see the event now what has that told you.
The event is happing the points and coil are functioning on a EI set up the module is trigging the coil. That’s about it but good info to have handy.

What we don’t know and need to know is spark health I will let you fill that one in lets get back to a light as a helpful tool.
Let say we have a N that starts runs well but sputters acts like a fuel issue it may clear up it may not it may run good one day the next it won’t. Install the light spark checker start the engine and monitor the light when the event happens if the light flashes a normal spark even as its sputtering are shutting down spark is not you problem. If the light shows a weaker light, are the light is strong and then weak are missing flashes I go straight for an ignition problem.

The number one issue I see is points new are old on an intermittent sputter acts like fuel issue they will light off a 12V test light hooked between the points and coil perfect it will fire a KV tester don’t take that to that bank spark is OK it will bit you. The prof on a runner is to back it up with a inline light spark checker and monitor the flash when the event happens as I have mentioned. I can do it with a KV tester only because I have ton’s of experience with it.

If a guy is not willing to answer the questions and not invest in a few simple tools I will not play with him. I am sure if my guess is 100% spot on I would not need to waist my money on tools. I use the tools to back up my game to rule out my best guess they can also… That’s diagnostics…

You need an adjustable spark checker and a inline (light) spark checker.



https://www.amazon.com/Car-Spark-Pl...amp;keywords=adjustable+ignition+spark+tester

https://www.amazon.com/Lisle-20610-...623&sr=8-4&keywords=spark+checker+kit

Whats the total timing its a must know question.

 

[michaelthorne75]

I'm still working on this but I noticed that the block is pitted around the # 4 exhaust port. Could this cause engine to run rough? I' looked at some older post on this and Bruce gave some good advice on fixing this pitted problem. So I'm gonna fix this next. Just wasn't sure if this would cause engine roughness or just another issue.

Thanks for the help.

 

[Royse]

"the block is pitted around the # 4 exhaust port. Could this cause engine to run rough?"

No, it would cause an exhaust leak in that spot.
If the rest of your manifold is not sealed properly, particularly
around the intake portions, then you might have running issues.

If I recall, you said you had an adjustable gap spark tester.
Have you checked spark? Did you check fuel flow through the carb?

In my mind, you have more than one problem right now.
The throttle response is one thing that needs to be addressed.
But even if it doesn't respond correctly, normally the engine will
run correctly and smoothly throughout the range if all else is working.

 

[Hobo,NC]

It should have the degrees on the flywheel mark 20 and turn it up that's your total. Are adjust till it runs the best at 18/2000 RPM if it still hesitates timing is not your issue.

I have never seen a worn throttle shaft cause a performance issue YMMV. I have never seen the intake gaskets leak YMMV Exhaust yes but not the intake part of it....

 

[michaelthorne75]

I'm gonna check the spark health later today. I got the tool hobo
suggested. I already had the regular inline spark tester and I'm
getting spark on all with it. Could be weak spark I guess.

How critical is the exhaust leak. Does it harm anything to leave it. Or
should I go ahead and fix it with the hi temp epoxy. It's around the #4
exhaust port.


Thanks

 

[michaelthorne75]

I'm getting a white spark across the spark tester on each one. So not
sure if that is good spark or not. Thanks.

 

[Hobo,NC]

Whut do you have it set at.

 

[Royse]

The exhaust leak is not critical to it running. I would leave it until
it is running so you're not adding any new variables to the equation.
Once it's running, I'd fix it as soon as practical.
Leaving it will cause the metal around it to pit worse.

 

[michaelthorne75]

The spark tester was set at about 1/4 in. Around the S on the scale.

 

[michaelthorne75]

Ok. Also is there a special thread sealant I should use on the
manifold stud. I didn't use anything on any of them, but the stud
closest to the front was leaking antifreeze, so I took manifold off and
used some regular pipe sealant and it's still leaking. Sorry for the
stupid question but I got all these weird problems on this thing.
Thanks

 

[michaelthorne75]

Also how much of a stream should I get coming out of carb bowl. I
got kinda a slow dribbly stream ??

 

[Royse]

I must have missed that you already had the manifold off.
The exhaust leak could be fixed since its already been disturbed.
I use red Permatex on the block end of the studs.

The carb should run a pint of fuel in about 2 minutes in a
steady stream. Its not a full stream, but fairly steady.

 

[michaelthorne75]

Ok. Do all the studs need permatex? Only one is leaking. Wasn't
sure if all go into water jacket.

 

[Royse]

If they all came out, I would use it on all.
If only one came out and is leaking, only do that one.

Are you sure the block isn't cracked around that stud hole?
Someone tried to repair this one.

 

[michaelthorne75]

No don't think it's cracked. The block was cleaned and manufluxed a
couple months ago. And I don't see any crack around it. I think I
used the wrong pipe sealant. I used no. 5 rector seal. It comes out
right on the stud nut. And kinda slows up. I guess it's evaporating off
as it hits manifold.

Also this is a newly rebuilt motor. Not sure if that matters.


The spark was a white spark about 1/8-1/4 in gap on the tester. So
not sure what that means.

Engine won't run below 700rpm. Not running smooth enough to stay
running. If that helps.

 

[Royse]

A newly rebuilt engine? I missed that too. It may matter.
Has it ever ran correctly since the rebuild?

1/4 in spark on the spark test should be good.
As long as it is consistent.

Check that gas flow too.

 

[michaelthorne75]

No never ran right. Has always ran rough since I started it up.

 

[michaelthorne75]

Also the gas tank has not had much gas in it. Maybe a couple or
three gallons of gas this whole time. Not sure if that will matter

 

[Hobo,NC]

It needs to be set at 2/0 red line the point of the needle dead on the red line. S/E is for small engines.

http://forums.yesterdaystractors.com/viewtopic.php?t=1170719&highlight=spark

 

[Hobo,NC]

If you get a constant spark at 2/0 spark is notchur issue. Color don't mean chit at this time. You then put the inline tester on and monitor spark during the event if is constant move on to other basic test spark is not the problem.

Manifold stud leak, Put a can of stop leak in the radiator sometimes that's all you can do and wait it out it will self seal if its just leaking by the threads.

A newly rebuilt engine whodathunk it. Its time for a compression check...

 

[michaelthorne75]

So spark will not jump the 2/0 gap. Only when it's a small gap. Does
this mean coil is bad?

 

[Hobo,NC]

Possible, other than that dirty points, bad condenser, poor point plate ground are insufficient power to the coil. No matter what other issues you have its mandatory spark jump a true 1/4" gap on your tester at the 2/0 line.

What we know the event is happening your light confirmed that.

What we don't know why is spark weak the spark tester confirmed that.

 

[michaelthorne75]

What an I do to check this. I have already swapped out the new
points and condenser with another new set. And then it wouldn't
even crank. So I put the other ones back in and it started up again.
I'm getting 2.2 ohms on the coil and 6v on the points while they are
open to the terminal on the dist. Not sure what to do. A guy who
works on these came by and told me it was I the carb but when I put
another carb on it, it did the same thing.
Amp meter doesn't move unless you advance throttle. But at idle it
just sits on 0.

 

[L.Fure]

(quoted from post at 00:00:40 10/29/17) What an I do to check this. I have already swapped out the new
points and condenser with another new set. And then it wouldn't
even crank. So I put the other ones back in and it started up again.
I'm getting 2.2 ohms on the coil and 6v on the points while they are
open to the terminal on the dist. Not sure what to do. A guy who
works on these came by and told me it was I the carb but when I put
another carb on it, it did the same thing.
Amp meter doesn't move unless you advance throttle. But at idle it
just sits on 0.

It could be both carburetors have the same problem. Have you checked for air leaks yet? It only takes a few minutes to do, then you can move on to others things.

 

[michaelthorne75]

I did check for air leaks as best as I could and no change. I sprayed
carb cleaner around and nothing. My plugs are black like they are
getting too much gas.

 

[Hobo,NC]

OPEN LINE VOLTAGE MEANS NUTTIN no matter what anyone says it means NUTTIN.... The circuit needs to have a load on it I like to use a automotive sealed beam head light to load the circuit remove the wire from the coil and insert a headlight points closed measure the voltage then. I doubt your issue is wiring from the switch to billy-bob it straight wire the coil directly from the battery.

If you want to play more screw down a set of points and condenser to a 2X4 wire it up just like its on the tractor use your coil can you make good spark if not one of the parts is defective.