1914 Harley twin timing marks

[garysanford]

I have a 1914 Harley twin, single speed, chain drive that I am trying to get running. I removed the timing cover and noticed the exhaust cam has a missing tooth. I want to establish TDC before I remove anything and also timing for the magneto as well. Are there marks for TDC and ignition timing? How do you find TDC if not?

[sswaney]

I believe your 14 would be similar if not the same as the later J Models. There should be only the one cam with multiple lobes and its related drive gear. Are you saying that gear is missing a tooth? As for finding TDC. It is done by directly measuring the piston location through the top cylinder plug which doubles as the motor/frame mounting stud. Rotate the motor in a counter clockwise direction when viewed from the left side and when you see the front intake close your coming up onto the front cylinder compression stroke. I'm not sure I would attempt to run it with a missing tooth on the cam drive gear.

[garysanford]

Yes, the gear is missing a tooth and I don't want to run it that way. I have not removed the cam cover as I wanted to find out about timing before I did. I can't find any marks on any of the gears under the magneto drive cover. This is the first Harley I've ever worked on (plenty of Indians) and I was expecting timing marks. I'll find TDC and make my own marks if I can get the cylinder plug out.
Any other advise?
Thanks for your help.

[sswaney]

Here is some information I saved, not sure of the source but I believe it is accurate.
As for timing marks on the gears of a 14 twin, I have no experience with that year but I would think there should be a mark on the cam gear and the pinion gear to orient them correctly. The other timing mark should be on the relief valve gear. Its corresponding mark will be located on the motor case just above the relief valve bushing. I may have some information on how to time that as well but will have to dig a little deeper to locate it. Maybe someone with more knowledge will jump in here?

Timing a Magneto Ignition
Firstly set the mag at FULL ADVANCE. That is with the interupter ring
rotated as far as it will go in the direction opposite to the rotation of the
magneto.
Then make sure that the pick-up marked 1 has its HT lead connected to
the rear cylinder. This usually means that the rearmost pick-up HT lead
will go to the rear cylinder and the front pick-up HT lead to the front
cylinder
Set the mag points at 15 thou.
I find a bit of cigarette paper between the points is about the best thing to
determine when they are just starting to open. You'll feel the cigarette
paper release if you're lightly pulling on it as you rotate the mag.
Now set the rear cylinder at 5/16 of an inch before TDC on the
compression stroke and then rotate the mag, ensuring the engine stays
stationary, until the points are just staring to open.
Now tighten the nut holding the mag drive gear to the mag armature just
enough to hold it firmly in place.
You now need to turn the engine over in it's correct rotation until the front
cylinder is 5/16 of an inch before TDC on it's compression stroke and
check that the contact points are just starting to open.
If they are you've timed your engine. If they're not you've timed it on the
wrong breaker ramp so go back and repeat the process but time the rear
cylinder on the opposite one you used the first time.
When you think it's right rotate the engine in it's running direction and
stop when the pionts open, cigarette paper releases, and measure where
your piston is. 5/16 BTDC.
By rotating and checking you take all the backlash out of the gear train
and get a more accurate setting but it does mean you may have to adjust
things more than once.
Some mag drive gears are keyed and some are not but I prefer to leave
the key out of any that are keyed as I find I can get a lot more accurate
timing setting.
If you prefer to keep the key you may find you need to advance or retard
the mag drive gear up to as much as 3 teeth from the factory marks to get
correct timing.

[c.o.]

Here is some information I saved, not sure of the source but I believe it is accurate.
As for timing marks on the gears of a 14 twin, I have no experience with that year but I would think there should be a mark on the cam gear and the pinion gear to orient them correctly. The other timing mark should be on the relief valve gear. Its corresponding mark will be located on the motor case just above the relief valve bushing. I may have some information on how to time that as well but will have to dig a little deeper to locate it. Maybe someone with more knowledge will jump in here?

Timing a Magneto Ignition
Firstly set the mag at FULL ADVANCE. That is with the interupter ring
rotated as far as it will go in the direction opposite to the rotation of the
magneto.
Then make sure that the pick-up marked 1 has its HT lead connected to
the rear cylinder. This usually means that the rearmost pick-up HT lead
will go to the rear cylinder and the front pick-up HT lead to the front
cylinder
Set the mag points at 15 thou.
I find a bit of cigarette paper between the points is about the best thing to
determine when they are just starting to open. You'll feel the cigarette
paper release if you're lightly pulling on it as you rotate the mag.
Now set the rear cylinder at 5/16 of an inch before TDC on the
compression stroke and then rotate the mag, ensuring the engine stays
stationary, until the points are just staring to open.
Now tighten the nut holding the mag drive gear to the mag armature just
enough to hold it firmly in place.
You now need to turn the engine over in it's correct rotation until the front
cylinder is 5/16 of an inch before TDC on it's compression stroke and
check that the contact points are just starting to open.
If they are you've timed your engine. If they're not you've timed it on the
wrong breaker ramp so go back and repeat the process but time the rear
cylinder on the opposite one you used the first time.
When you think it's right rotate the engine in it's running direction and
stop when the pionts open, cigarette paper releases, and measure where
your piston is. 5/16 BTDC.
By rotating and checking you take all the backlash out of the gear train
and get a more accurate setting but it does mean you may have to adjust
things more than once.
Some mag drive gears are keyed and some are not but I prefer to leave
the key out of any that are keyed as I find I can get a lot more accurate
timing setting.
If you prefer to keep the key you may find you need to advance or retard
the mag drive gear up to as much as 3 teeth from the factory marks to get
correct timing.

I'm definitely not super experienced with a '14 H-D (yet..) I do think you've pretty much got it covered except my understanding is the mag has to be fully retarded. From what I've been told, it's a matter of finding TDC on the rear cylinder, retarding the spark fully, rotating the mag until points just break and ensuring that nothing moves when the gear is being tightened.

Gary, the pre-16 experts have been a little quiet here lately but I'm sure a definitive answer will show up. Marking the gears prior to removal is definitely a good idea!!!

[c.o.]

Well sswaney... it looks as though I was talking through my hat. Timing is fully advanced.

Gary, I contacted our resident '14 expert (Slojo) and this is his reply. I hope this helps you out.... when you get a chance it would be nice to see a photo of your Silent Grey Fellow.

"Timing is 35 to 37 degrees BTDC using the rear cylinder as number one. Firing takes place right when the points break open. The magneto ignition interrupter drum has roman numerals stamped on the face edge to inform #1 or #2 cylinder interrupter cam. Use a degree wheel to find a location common. Say 10 degrees each side of TDC Then divide the distance by two to find actual TDC. Now back up the motor 37 degrees before TDC. Rotate points to crack open and tighten magneto gear to shaft , do not use key on mag. shaft/gear set. Make sure interrupter drum is in the fully advanced position."

[duffeycycles]

All HD's that I know of are timed to the full advance position..when looking at the full advance mark on the flywheel!

[c.o.]

All HD's that I know of are timed to the full advance position..when looking at the full advance mark on the flywheel!

I dug through some early literature and more than one source indicated that the mag should be retarded. I know... weird eh? Anyway, I have no doubts that Joe knows what he's talking about and "advanced" it is!

[Tommo]

Cory,
If you time any motor that has manual advance and retard spark at full advance you get a miles more accurate result because the ammount of piston movement to crank rotation is less than at full retard.
Generally you'll find that full retard is very close to TDC and at this point because the crank rotation to piston movement is large due to the rock as the piston changes direction you do not get very accurate results.
Hope this makes sense.

[c.o.]

Tommo,

That makes perfect sense. I was aware of the advance timing method for later bikes but for some reason, (which doesn't make a lot of sense right now) I was under the impression that it was the opposite way for the older stuff. In fact one source was Victor Page's "Early Motorcycles" pg. 274. Maybe I interpreted it wrong?

[duffeycycles]

On later bikes retarded timing [a sporty is about 10 deg before BTC] [a big twin is about 5 deg BTC]BTC=before top center
------critical to do advance timing

[garysanford]

Thanks for all the information. I marked the gears at TDC so I can get them back where they belong and then time the mag. Thanks to everyone that responded with information. Here's a couple of pictures.
IMG_1410.JPGIMG_1411.JPG

[c.o.]

That's a funky paint job! Thanks for posting the pics! I'm a big fan of the early Harleys and I'm digging that Simplex too!

[garysanford]

The story is it was restored in the '50s. It has 1913 painted on the tank and was sold as a 13.
Here's another question: how does the twist grip come off of the handlebar. The spark control cable has come loose and I need to re-attach it. I removed the plug on the end of the handlebar but something is holding it on. I think the grips are original and I hate to mess them up looking for a screw or pin.

Good eye Cory, that's a '40 Servi-Cycle in the background. It it the only one I've seen with the original version of the single clutch pedal when they changed from direct drive. My apologizes for posting a late model picture on the pre-16 board.
Servi_Cycle.JPG

[c.o.]

Well since nobody is speaking up and I've yet to pull a set of early bars apart.... do I see a small screw near the top (closest to the centre of the bars) and there is not a bolt/screw hiding under the plug you removed?

Every time I see somebody riding a Servi-Cycle they have a grin on their face. Thanks for the nice pic of yours.