Magneto Timing Position

[billpedalino]

Gentlemen,

I'm installing the magneto into my Sportster motor and there is a problem with the magneto position when it’s properly timed. This is a 1964 CH which uses the DC Linkert with the round air cleaner and lever-choke. When the motor is in the front cylinder firing position (Front intake valve returned-down and timing mark in center of hole) and the magneto body turned counter-clockwise until the points just start to open, the magneto is turned too far out and it interferes with the air cleaner backing plate. Advancing the rotor drive gear 1 tooth on the cam drive (36° of rotor rotation) advances it way too much and the magneto is too close to the rear cylinder. With the magneto that close to the cylinder, I can’t get any spark retard for starting. Also, I’m using the ’65 and later advance setup (I also have the original 'locked-magneto' plate' as well). Yes, I know it’s wrong for 1964 and that the judges will 'correct' me by assigning the appropriate point deduction, but preserving my 62 year old bad knee that was damaged in starting this very bike at age 20 is certainly far more important than a couple of AMCA points, should I choose to have it judged.

People familiar with Sportster magneto setups will probably inquire as to the following:

1. I checked the motor timing position twice and its correct.
2. I checked the point gap and its correct (as I suspected as you installed them).
3. I tried one tooth back and one tooth forward on the magneto/cam gear purchase.
4. I used the old pin temporarily to mount the gear, as I suspected that the gear might have to be removed, turned and replaced.
5. The tapered screws for the cam cover-magneto mounting plate to not protrude above the flat magneto mounting surface.
6. The magneto sits flat and squarely, and bottoms onto the mounting plate.

In the past, I’ve had this trouble with aftermarket gears that had an incorrect hole location. But this is an OEM gear and rotor. In fact, I compared this gear to another OEM gear from another original magneto that I own and the pin hole looks to be identically located, so I suspect this is not the problem. Also, it appears that turning the gear 180° on the rotor shaft will not help, as there are an even number of teeth and flipping the gear yields the same magneto firing position. I’ve attached a photo of the two OEM gears placed together. As you will note, the holes are drilled in identical locations.

I’m now thinking cam gear timing, as I just can’t think of any other reason why the magneto is out of position. It’s all OEM parts and it was certainly positioned properly when it left the factory. Having built many, many Sportster motors I always pay careful attention to breather, pinion and cam timing during assembly - but maybe I screwed up? But at this point I know that I’m second-guessing myself, as I installed the cams over a year ago. If I skipped a tooth on the cam, I would think that it might throw the magneto position out as indicated, but I’ve never made that particular mistake so I don’t know for sure. Also, I'm not sure tha the drive (worm) gear on the end of the cam would advance the rotor gear enough to cause a substantial swing in the mangeto body if I'm only one tooth off - but possibly.

I know I'm being lazy, but God how I hate to remove the cam cover and disturb a now-pristine, newly assembled cam case. Therefore, with the advantage of maturity (nicer way of stating 'old') and experience, I'm reaching out before I disassemble. If anyone can offer any other credible suggestions before I remove the cam cover, I would greatly appreciate it. I've seen this problem before, so I'm certain that some of my fellow motor builders out there in the 'cloud' have dealt with this as well.

Thanks ...

[Sargehere]

Location of the hole in the gear makes not a whit of difference. The gear teeth are symmetrical all the way around. I've used Fairbanks-Morse Sportster magnetos in my ULs many times, and never had a problem pulling the mag up from engagement with one cam tooth and dropping it down to engage another; it's just a matter of finding a position for "advanced" that you can live with that will also allow you to turn it to "retarded" position and back. I doubt that there's any reason to disassemble your entire cam chest. I've never found one that you can't adjust.

It's a combination of finding where the engage the gear on the cam so that the narrower end of the points cam is about to break the points, and that the mag is allowed to retard (clockwise) from that point and where the mag body points when that happens. There should be at least two positions, using the stock Sportster parts. May I suggest that you don't think "one tooth" this way or "one tooth" that way, but more like "pull the sucker out and spin it around!" (?)

[murph]

You are using the 3 factory spacers between the carb & manifold for the xlch correct? I had the similar issue as you can see it is very close but works. You can just about fit a piece of paper between the mag and air cleaner.

[billpedalino]

Murph,

Yes, I am using the 3 insulators between the Linkert and the manifold. However, I went through all of my old magnetos and panhead/knucklehead timers (they have the same drive gear) and noted that the hole locations are slightly different on some gears. It appears that the hole locations are not really indexed acurately when drilled. I'm going to remove one of the gears that has the hole located approximately 1/2 tooth out from the gear that I'm using and see if that work any better.

[billpedalino]

Murph,

That is one absoultely beautiful Sportster......

[murph]

Murph,

That is one absoultely beautiful Sportster......

Thanks! I also have a 69 with the mag advance and have to say it really doesn't help the knee that much. So maybe start from scratch to see how it lines up with out that advance set up and go from there. Or if your not concerned with stock as much, try adding another stock spacer with longer bolts. The average joe is not going to see you have 4 instead of three.

[billpedalino]

Murph,

Do you have a close-up pic of the left side of your bike showing the oil tank hoses and fittings? I have three different horseshoe oil tanks for this bike and I want to make sure that I use the correct one. My recollection is that when I bught this this bike MANY years ago as a stone-stock '64 CH, there were 4 oil tank fittings on the vertical face of the tank, including the adjustable chain oiler block and valve, plus the bottom drain plug. I'm certain that the drain plug had no attached fittings - it was just the plug only. Others say that's incorrect. But, I also think that the oil tank changed in '63 or '64 when the deep-well drain was added. Please advise.

Thanks.

[murph]

Here is a shot of a 59 ch with the chain oiler hose and the brackets.




This is the exhaust side of 62 ch



Here is the primary side, the bracket and bolts should be parkerized which I fixed. This is an old shot but the lines are the same.



I think 64 ch should have the barbed oil tank feed, I think it started late 62. Someone can correct me if im wrong.

[kg993]

Bill, did the differently indexed gear do the trick? I was wondering if the thickness of the 65 parts is different than origional for the motor. If so the heigth difference will change the advance or retard of the shaft.
Kerry

[billpedalino]

Kerry,

I recevied a gear with a 1/2-tooth hole difference from Dave Shaw at Morris Magneto. It does make a difference, but not enough to solve the interference issue. I turly can't figure out why - it makes no sense to me. At the firing position the cam drive doesn't move, the point gap is kept constant, and the hole in the rotor obviously doesn't move. The ONLY variable is the hole in the gear and how it advances or retards the point cam at the firing position. Between all 5 gears, I'm getting a full 18 degree variation in rotor location and it's not enough to make an apprecaible difference! I don't get it! Obviously, I'm missing the concept here.

I did find that adding one more insulator between the carburator and the manifold (total of 4) easily solves the air cleaner interferance problem, should I NOT be able to figure this one out. But I simply hate to give in! I'll speak with Dave Shaw again - he has 40 CONTINUOUS years of experience with magneto Sportster and he's never reluctant to help. I really recommed Morris Magnetos - great guys.

Murph,

EXCELLENT photos - thanks so much. Your '62 has exactly the same hose connection configuration as my '64 did when I purchased it. Some of the guys on this forum say it's wrong for the '64, but I KNOW it was stone stock when I bought it; 4 years old, flogged to death and never taken apart.

I do have a question about the front, lower oil tank bracket - what is the finish? I can't really tell from the photo. I seem to recall that it came gloss black just like the oil tank, but your's looks like its cadmium or grey.

Also, Until I reviewed your photos, I didn't remember the top oil hose clamp for the chain oiler hose that mounts to the top surface of the rear motor mount. Looks like I'm going to have fun trying to locate that one - I don't think I've ever seen one at the meets or on fleesebay. Might be a home-fabrication-and-parkerize item.

[murph]

The bracket should be parkerized for the oil tank along with the bolts. My 62 pics are older and the finish was incorrect at the time. I have since corrected the finishes but have no up to date pics. The chain oiler brackets are tough to find. Maybe you can post some close ups of your issue with the mag in the motor. They were close. Here are some shots of another 62 I did, it was close as well.

[billpedalino]

Problem solved - As Murph suggested, I added another white insulator between the carb and the manifold and that afforded plenty of room. This is what I think is going on; I'm using the '65 and later advance setup. 1965 was also the year that the oval air cleaner was introduced. I believe that the bottom of the oval air cleaner backing plate was slightly higher than the round one (I didn't dig an oval one out of storage, so I'm guessing), thus allowing a little more swing toward the advanced position. If I installed this as a fixed-magneto, I would have simply dropped back a tooth and positioned the magneto closer to the rear cylinder, locked it down and would not have given it another thought. In any event, it now advances and retards properly and the 4th insulator is not even noticable, except to an astute judge. However if and when I decide to have the bike judged, I'll install the locked-mag plate and left handlebar for that process.

Thanks for all the input!

[murph]

The 65 still had the round air cleaner cover, not to throw a wrench into your thoughts though. Glad to hear your on your way!

[billpedalino]

I've been wrenched! '66 was the oval air cleaner!

[vph-d]

How about a picture of the dealer sticker on your oil tank? That kind of detail is wonderful. Both machines are great examples of why the XLCH ruled the road back in the 60s. They looked as fast as they were just sitting still. If it helps, the p/ns for the hose brkt clips are 63611-53, and 63612-53.
VPH-D