Number One Cylinder Doesn't Line Up With Timing Marks...

(TO-20) I didn't know that was possible?!? How do I check timing?

I turned the engine by hand, until number 1 was on the compression stroke, but the timing marks were nowhere to be seen.

I think I can see where someone has written a number "1" on the flywheel, but I didn't check if it corresponded to TDC on 1.

What's the deal?
 
Getting an engine "exactly" on TDC without
pulling the head is nearly impossible.

You can pull the #1 or #4 spark plug (which ever
is easiest to see into) and turn the engine
through until you see the piston come up, or
reach in with a thin screwdriver and feel the
piston come to the top. This won't get you to an
exact number but it should bring the timing mark
into the window.

If you do this and still don't have a timing
mark, all I can assume is somehow the flywheel is
bolted to the crank in the wrong position. Not
sure if this is even possible, depends on the
bolt pattern.

If all you are trying to do is set the timing,
just play with the timing, you'll know when it's
close enough.
 
"Getting an engine "exactly" on TDC without pulling the head is nearly impossible."

Actually, Steve, since this is an OHV engine it should be quite EASY to locate TDC ACCURATELY with the cylinder head in place. (Unless there is something unique about this engine that blocks access to the piston from the sparkplug hole.)

Using a piston stop, carefully rotate the crankshaft until the piston hits the stop in both directions, and mark those points.

True TDC is EXACTLY halfway in between.

The video linked below shows a guy doing just that with a small block Chevy.

The procedure for most any typical OHV engine is exactly the same.
Video
 
The 4 stroke, intake, compression power and exhaust takes 2 revolutions to complete which means you are on the exhaust stroke and not the compression so turn it 180 degrees till 1 comes to top an you should be at 6 degrees before tdc.
 
(quoted from post at 10:26:24 09/08/14) The 4 stroke, intake, compression power and exhaust takes 2 revolutions to complete which means you are on the exhaust stroke and not the compression so turn it 180 degrees till 1 comes to top an you should be at 6 degrees before tdc.
Thanks, 2. I was sure that I was on the compression stroke, but I'll try again this evening.

With a finger over the number 1 spark plug hole, would there be any pressure at all on the exhaust stroke? Wouldn't there only be pressure on the compression stroke?

I have the valve cover, gas tank, etc. installed, so I have to do this by pressure - I can't see what the valves are doing.
 
(quoted from post at 14:01:02 09/07/14) (TO-20) I didn't know that was possible?!? How do I check timing?

I turned the engine by hand, until number 1 was on the compression stroke, but the timing marks were nowhere to be seen.

I think I can see where someone has written a number "1" on the flywheel, but I didn't check if it corresponded to TDC on 1.

What's the deal?

Cylinders 1 & 4 are on TDC at the same flywheel position. You can set timing using either cylinder. Pop the cap off of the distributor and you can tell what cylinder is on the compression stroke, the rotor tip will point to that cylinder.
Pull all the plugs to make it easier to turn the motor. Hold a thin screwdriver as upright as you can in the #1 spark plug hole. As the motor turns, the piston will push the screwdriver up. At the moment the piston stops moving up, you will be very close to TDC. Look into the timing hole for marks. If you don't see any, remove the screwdriver and slowly rotate the motor backwards for 1 wrench flat, and if the marks don't show, rotate the motor forward 1 wrench flat, then a little bit more. If the marks [u:f7f22a5548]still[/u:f7f22a5548] don't come up, then you got a problem.
Use a good pen light, and perhaps another person to look while you turn, or vice-versa. Good luck,
BillL
 
If the marks [u:32e00749b9]still[/u:32e00749b9] don't come up, then you got a problem. Good luck, BillL
ill: I've got a problem! :shock:

The marks start to appear right [u:32e00749b9]after[/u:32e00749b9] cylinder number 1 has finished the compression stroke. The marks don't correspond to TDC on any cylinder.

It looks like someone has marked the flywheel with a permanent marker, showing where number 1 is starting up on the compression stroke. Then, there's a different mark that [u:32e00749b9]may[/u:32e00749b9] show TDC on number 1. I'll try to confirm that, using the method you suggested.

How can I time the engine? Vacuum gauge? I don't know how to time by "ear".

The tractor starts and runs fine, so I guess it could be worse.
 
Can"t think of why your tractor is doing that, could it have the wrong rods, or someone turned down the crank to fit the wrong rods or wrong flywheel, I"d pull the starter and look. Maybe PO couldn"t get flywheel on and wallowed out the holes. It only fits one way. Hold the front crank bolt and try and rock the flywheel.
 
As Bob suggested in an earlier post you will need to find TDC. Once you find that you can mark the front crank pulley or mark the flywheel whatever is easier. They make an adjustable advance timing lights, Summits sell them for one, I have one.

http://www.summitracing.com/parts/ino-3555?seid=srese1&gclid=Cj0KEQjwyrqgBRDepamt-LWA2oABEiQAV7nwwHu7nzSXHmac-O4LNkv9o_SnYseTfalWPB8LdcFiUAwaAs1s8P8HAQ

If you have one of those you could set the timing by using the TDC point and adjustable timing light. No big deal, it can be done without much drama.
 
Thanks, all.

My next job will be to find TDC on number 1, or to confirm that the Previous Owner/Mechanic already did. (There's a mark on the flywheel that may be it.)

Dr. Loch, thanks for the advice on the timing light, although I'm not sure I understand what it does: does the light make it's own adjustment (internally) for degrees of advance at a given RPM, but still flash at TDC, so you only have to find the TDC on the flywheel?
 
Yes it does, you would dial it to the amount of advance you want and it offsets the strobe light. That being the case once you have found TDC you would set the advance on the timing light and then with the engine running you would turn the distributor until your marks line up again.
 
Tom, I told you how to find true TDC. Once you have done that, you can use a timing light with the "advance" feature, or simply figure out what the OD is of the flywheel, then figure out the circumference, and then the inches (mm?) that would represent the desired degrees from TDC and make your own timing mark. BT,DT, MANY times.

This can be done with ANY engine. It's NOT rocket surgery!
 
I think I was utterly, completely, totally wrong... :oops:

Bob, I didn't have a piston stop, (To tell the truth, I didn't know what a piston stop [b:7f04ef23bb][i:7f04ef23bb]was[/i:7f04ef23bb][/b:7f04ef23bb] until I Googled it!) but I improvised with a plastic rod, and I could also see the piston with a flashlight.

I turned the engine several revolutions to make sure I had found TDC, then, making sure I was on the compression stroke, I carefully brought the piston up one last time so I could mark the flywheel.

To my surprise, the "DC" mark on the flywheel was already lined up with the notch!

I don't what I was doing wrong before. It got too dark to work any longer this evening, but I'll check it again tomorrow.

Bob, it's a good thing this isn't "rocket surgery"! (I'm such an idiot.)
 
(quoted from post at 20:20:48 09/09/14) I think I was utterly, completely, totally wrong... :oops:

Bob, I didn't have a piston stop, (To tell the truth, I didn't know what a piston stop [b:f29235844b][i:f29235844b]was[/i:f29235844b][/b:f29235844b] until I Googled it!) but I improvised with a plastic rod, and I could also see the piston with a flashlight.

I turned the engine several revolutions to make sure I had found TDC, then, making sure I was on the compression stroke, I carefully brought the piston up one last time so I could mark the flywheel.

To my surprise, the "DC" mark on the flywheel was already lined up with the notch!

I don't what I was doing wrong before. It got too dark to work any longer this evening, but I'll check it again tomorrow.

Bob, it's a good thing this isn't "rocket surgery"! (I'm such an idiot.)

Hey, Tom, I was just giving you little good-natured ribbing!

I think you are well on the road to figuring this out, and are learning as you go!

Can't beat that!

Please post back with progress reports!
 
Hey, Tom, I was just giving you little good-natured ribbing!
Oh, I know, Bob. I just felt pretty silly. (I seriously considered deleting my YT account and never showing my face around here again! :oops:)

Thanks again to everyone for your help. I'll keep you posted.
 
Hey Tom, don't feel bad or silly, this is all part of the learning process not only for you but for others that may face the same situation and are following your posts. As I've been told and have learned, there are no dumb questions. How do you think some of us that have responded have learned, been there, done that, have the tee shirts and a lot of broken expensive parts to prove it.
mvphoto10889.jpg


How much do you think this cost?
 
(quoted from post at 02:20:48 09/10/14) I think I was utterly, completely, totally wrong...

Rare the man who will type that. But the mark of a good one, generally.

I've learned a lot reading the questions and answers that come up on this forum. Sometimes we learn most when someone makes an error. It may be embarrassing for them, but the store of knowledge for the rest of us increases. And we'll all take a turn someday, probably.
 
(quoted from post at 09:28:21 09/10/14)
(quoted from post at 02:20:48 09/10/14) I think I was utterly, completely, totally wrong...
Rare the man who will type that.
've had plenty of practice being wrong, Jeremy - just ask my wife! :wink:

Actually, I shouldn't have qualified my first statement with "I think..." I was just [b:df1d60fd0c][i:df1d60fd0c]flat wrong![/i:df1d60fd0c][/b:df1d60fd0c] (Usually, if I give a wrong answer, I just try to say "I didn't understand the question", but that wouldn't work this time. :D)
 
What you see is a piece of a titanium intake valve..... We had some valve springs that were considered "defective" by the manufacture. The manufacture offered to send replacements. We found a different manufacture. Valve springs were cheap compared to what it cost to fix the motor. When that one came apart I found some of the carnage in the bow of the boat, wrist pins, rings, valves.. not a pretty sight.
 

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