I got a friend's 1913 tourer back together today, after a 2 year hiatus while a new transmission was built. It started right up, both on battery and magneto, with the crank handle and the newly fitted starter motor, but no 1 cylinder is a non-contributor.
First, we swapped no 1 coil with no 2 and it made no difference. So we fitted another spark plug in no 1. No change. Swapped no. 1 and 2 plugs over. No change.
Cleaned the new day timer, checked the contacts in the coilbox and cleaned same. No difference.
We removed the side plate and checked valve acctuation. No stuck valves, clearances a little wide at .025" but that should make no difference.
Checked and tightened the manifold clamps to eliminate any chance of an induction leak No difference.
All of this on a freshly reconditioned motor just two years ago, which was running well when removed for the trans job.
Your suggestions please fellows. I can't make sense of this one.
Allan from down under.
Does its compression on the crank approximate the others?
Did you try it with a squirt of oil in the #1 cylinder?
How do you know that #1 is missing?
If it lack of spark - did you look for tracks in the coil box?
I was tempted to suggest you begin by looking under the vehicle for #1
but got myself under control before I made a fool of myself.
Did you look on the workbench?
woops - lost control again!
Two things you don't mention: 1 is there spark actually at the plug and 2 compression. Pull the #1 plug ground it and check for spark. While it's out check for compression. No gauge? Put a thumb on the hole and crank it. It will at least tell you if anything's there. Nothing or very little? Shoot some oil into the cyl. and try again. If it seems higher you've got frozen rings.
Electrical things to check you haven't done yet:
Is your wire between the timer and the coil box grounded somewhere other than inside the timer when the rotor makes contact? Sometimes it will be grounded to a bolt in the crankcase. The bolt under the timer should be turned with the nut facing downward to prevent this from happening. Or the wire can be bare from constant movement of the timer when you retard or advance the spark, making contact with the timer cover, or the timing gear cover or the timing rod.
Sounds to me like either a burnt or stuck valve which will either lower the compression in the cylinder or make zero compression. Or the spark is not getting to the spark plug.
Norm
Fellows,while it was running, I shorted out the plugs with a screwdriver and had a good spark on all four. I removed no 1 plug and cranked her over by hand and had a good spark at the plug, so surmised that all was ok with the timer/wire to coilbox/plug lead.
While hand cranking I ran the plug shorting test with the screwdriver on the other three cylinders and all were fine, just like no 1.
Terry, I guess that takes care of your list, except for the carbon track. What I can't reconcile is that this is a new restoration, with minimal miles on it, and this problem is a sudden start-up.
I did not do a compression test. Without having a stuck valve, I do not think it has done enough miles to have burned a valve enough to take the pot right out. When I short the plug/coil, it makes NO difference to the running. It is not just weak on no 1, there is nothing there!
I will run your test on the timer to eliminate that as the cause.
Thanks for the suggestions fellows. I will return.
Allan from down under.
Allan,
On a new rebuild it is possible that you got steel valves instead of stainless steel, and if your guides where reamed out it is possible the valve is stuck open.If it has set for a while for the trans work it may of got condensation in that cylinder, Pull the plug, turn over slowly with your thumb on top of the cylinder hole and see if you have compression? Hope this helps!
Allan,
A couple of ideas.
Just to eliminate any problem/shorting in your coil box, switch number one and two timer and spark plug wires and see if it still misses on #1. That is, the coil that is in the #1 position in the coil box will be firing #2 cylinder and vice versa.
The other suggestion is to try adjusting/leaning the fuel mixture a little to see if that makes any difference. I had a #1 miss and it was because it was a little to rich. #1 runs colder then then #2, #3 and #4 and if it is a little too rich, it will be the first to miss fire.
Jim
It is entirely possible that the valve on cylinder #1 will move when the camshaft turns, but it is binding and will not completely close. Binding could be caused by varnish deposits, carbon deposits, or a weak valve spring. That would cause very low compression on #1 and a misfire on #1. That would also explain the wide gap on that valve.
Norm
That's a good call Norman.
Allan,
I think you may have a leaky gasket or ring/gland on the front intake port for #1 and #2 cylinders. With the engine at a fast idle, spray some carburetor cleaner around the outside of the intake manifold where it meets the block, and see if it runs smoother and faster as it sucks the carb cleaner into the joint.
I recently had the same symptoms on a friends Model T. He had tried changing carbs, sparkplugs, timers, coils, etc. It was just a leaky gasket, but it affected #1 more than #2.
Jim, I had thought of doing just that but had no product to use. So I tightened the manifold clamps as far as needed and left it at that. Next Tuesday is the day set to iron it out for keeps. I'll try your trick first, and may not have to do much else.
Thanks for your interest.
Allan from down under.
If spraying a flammable on a hot exhaust puts you off, you can use water.