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Points Backing plate eccentric screw replacement

5K views 26 replies 6 participants last post by  TR7RVMan 
#1 · (Edited)
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1971 Tiger TR6R 650
Points plate backing plate eccentric screws were barely usable, mostly rounded off and soft. There are brass eccentric replacement screws online however im not sure if they are only for the secondary adjustment plates or work for both the secondary and primary backing plate. As said before I need to replace the primary backing plate eccentrics & for $4 might as well replace them all. And yes, I still run points... ANY comments would be appreciated unless they are about the P.O.'s use of electrical tape ?

Backstory, bike was purchased in very rough shape at a bikeshop in Los Angeles and xported to San Diego, bike was timed and diagnosed, as soon as it ran I noticed lots of white smoke on left pipe, tore down the top end and found .060 worth of gouges in the bore. Barrels and head are currently at a machine shop with new .060 over pistons.
 

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#5 ·
Hi Orbweaver88, Just had a points plate apart the other day. I think the original eccentric screw on these later plates were zinc?? & quite weak.

Take it all apart & check for burrs etc. on the backing plate slots & edges of the sub plates. You'll see how the sub plates have "pins" that locate in the curved slots. I put a very thin smear of grease on back of sub plate & pins so they can slide more easily.

I'd replace all the other screws that have damage to slots also.

Brass replacement eccentrics would be better than the soft zinc. Put a small smear of grease on both parts of the eccentric as it really reduces damage by allowing the plate to slide smoothly.

I have a dedicated screw driver set with perfect tips that I just use with points plates as the screws take damage easily. I also recommend putting a tiny dab of grease on screw threads as it allows them to be moved easily, yet they will not back off once fully tightened. I've been doing the grease on threads for 40 years & never had a problem, but it really keeps threads from galling & moving smoothly so it's easier to back them off just the right amount to move eccentric without damage.

I like points. Well serviced they are very, very reliable & allow starting with a dead battery. Poorly serviced they will give problems. The big advantage of Boyer or the like is the advance curve is full advance at 3500 instead of 2000 rpm. You can modify springs on AAU to give a higher RPM for full advance. This tends to dramatically reduce pining with modern fuel.
Don
 
#6 ·
Don, that makes sense to use grease on the threads either way it cant hurt.. This particular points plate could use some revamping by installed new secondary plates as these plastic followers are actually visibly worn from lack of lubrication on the AAU cam and swabs on the plate. Its cool to know some people still appreciate points especially considering like you said about ability to start the bike without battery voltage which had not crossed my mind. Do you know anything about condensers in relation to their ability to stand the test of time. the coils points condenser are all factory fresh circa '71 haha; the bike ran on 1 or 2 kicks before tear down and my humble philosophy is if it isn't broken why replace it. If anything my concern would be the condensers might not be very effective.
 
#7 ·
Hi Orbweaver88, I don't know the service life of condenser. On my bike I'm still using ones I installed in 1976 6k miles or so. Same with points. Bike has 31600 miles on it now. Was in storage 34 years. They are still working ok. I get no undue burning of contact faces.

We always changed points & condensers as a set. But it was probably not needed. Running you'll see some sparking at points. Bad condenser allows too much sparking & points burning. If condenser is shorted to ground, you'll have no spark. How much sparking is too much? I really don't know. I've never pulled wire off condenser to compare. So if bike starts & runs you could leave old ones for now.

Lack of lube on rubbing block is #1 cause of points loss of spark by far. On short trips lube not so important as the rubbing block doesn't get that hot. On long rides the rubbing block over heats & wears quickly or melts unless well lubed. The felt blocks certainly help, but they really are not adequate at all. We do many rides where we ride 8 hrs solid with only fuel & restroom breaks. Maybe a very brief lunch stop side of road. This ride will wear poorly lubed rubbing block & it's not uncommon to see that until owner learns about points lube.

In the photo of points plate posted you see a 3 pointed oval logo on points. That is DAIICHI Japan. They make points & condensers for our bikes. Real original Lucas are no longer made. The Lucas you see sold are actually made by Daiichi. It has been said they actually made points branded Lucas back in the day, or Triumph installed Daiichi at factory. I have no idea if true or not.

The fit of Daiichi may not be as perfect as NOS Lucas, but I've used them on a few bikes & had good results. The key is lubing rubbing block of points & good enough surface on points cam, meaning not deeply grooved or rough that will sand rubbing block off. Generally grooving is caused from lack of lube at some point. The old fiber rubbing blocks would groove cams much more quickly if not well lubed.

If your cam is grooved polishing with 400 emory, finishing off with 800 or grey 3M emery pad would be advised. If too bad a replacement is needed. MARK EVERYTHING FIRST SO IT GOES TOGETHER SAME WAY! Take AAU apart & look at the slots in fly weights. The tend to wear flat spots with a sharp edge. This gives a notching effect on timing & can cause erratic running at slower speeds just off idle like in a parking lot or at red light if idle is slightly fast as it often needs to be. Polish these with 400 laid on a small file or strip of metal. You'll notice play in weight springs. Or almost play, feeling very weak. This is normal from new. However I find if you shorten spring a little about 1/2 the loop of one end of spring it makes bike run better. New springs from eBay are a crap shoot. Some heavy duty ones Triumph recommended are actually worse. I'm still working on how much to shorten springs to get full advance at 3500. Old posts by Mr. Pete are a good guide to start with if you want to persue better running. But get bike going for now.

In the photo of my points lube I'm using green Mallory cam lube. That is no longer made. Now I recommend Lubricam SL-2 cam lube. Easy to get on eBay. Few auto parts stores sell it. Put only 2 drops motor oil on felt blocks.

On as aside, if you have oil leaking into points cavity it tends to cause more burning of points. However even mildly oily points will often give enough spark for motor to run. Water/moisture on other hand will kill spark very quickly. Even riding in fog can cause lack of spark if it works it's way into points. In my mind the correct wire sleeve seal # 70-4707. It is tapered rubber sleeve pushed in from right side into timing cover. However.... if points plate is installed, you can split sleeve lengthwise & put in bore from left side putting sleeve in motor casting. I use a thin smear of silicon sealant with splitting & installing from left. Water thrown from front wheel or fog loves to follow wire into points.

Here's photo of my points. Notice my eccentric screws are not too good. I did that before I got smarter.
Don
 

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#8 · (Edited)
Gentlemen,


Regarding a few questions/point discussed (no pun intended).


Distributor Cam Lube; Pat Owens, West Coast Service Manager for Triumph, recommended the Harley Dist. Cam Lube above all others. No problem with what Don is recommending it is available at my local OReiley's Auto for 6.99 a tube.


Asa far as the Daiichi points and condensers were they the OEM manufacturer for LUCAS? I don't know they could have been. When Lucas went to the orange/white boxes from the red/black boxes the point of manufacture was all over the world. Once we got a load of pattern LUCAS turn signals in that were an exact copy from the wire to the logos and trademarks embossed in the head. Everybody outsources and have for years. Back to the Daiichi question. I would only use the original LUCAS, LUCAS-Daiichi (current LUCAS products) or Daiichi (black and maroon box) products in my machines. At the shop I worked at we usually didn't change the condensers on the OIF bikes for two reasons. (1) Labor time to change them and (2) we got enough defective new ones the decision was made if the unit was good not to mess with it.

Points vs Electronic Ignition. My preference is points. My 70 has points and a 2MC capacitor with a battery while my 78 is points and battery. Either can be started & ridden without a battery in series should it go flat. Not possible on my 79's with the factory E.I.. Should I have an AA advance unit go bad I would consider using an aftermarket E.I. due to cost factors. I have installed them in bikes and recommended them to guys who are building baskets. Also I have seen more bad black boxes in the aftermarket than I have seen contacts falling of a set of points. Many guys out here have problems with either style ignition and other items as they do not understand certain operating principles of this 40 plus year old machinery.


A lot of this boils down to personal taste and abilities. There is no best


K
 
#9 ·
Hi KADUTZ, Thank you for the very informative info on points & condensers! Most interesting.

Does Harley still make points cam lube?

I was Harley tech at HD of Oakland 1970-71. The points lube was indeed excellent, as was the HD Chain Saver chain lube.

When I got my bike out of storage I ordered a new can of Chain Saver, thinking it would give good chain life. Not even close to being the same. Was very thin & smelled of Kerosene. I used it a few months. Flew off instantly. Chain wore quickly. Gets better... 20 miles in the rain, the next morning chain was solid rust! I just started using GL5 differential oil. Has worked quite well, no rust, but of course messy as the old Chain Saver was.

I hope the points cam lube is better.
Don
 
#10 ·
Don I usually used PJ1 chain lube. Never had a problem with it washing off. GL5 has to make a mess.

Is Hardly still making cam lube? I don't know bought a couple of tubes a long time ago. Still have some a tube lasts a while. Might call tomorrow out of curiosity.

K
 
#13 ·
I took the point plate off the shelf and began disassembly, The eccentric screw on the actual backing plate has some kind of retaining washer holding those 2 screws in, the secondary plate eccentrics popped right out.. I can post a picture if you guys need to see what im describing, otherwise all words appreciated, its not a circlip btw.
 
#14 ·
BTW!! whats up with these sets of screws having the same part number but looking different?? the eccentric cam on steadfast has a much longer throw where as the Bonneville Shop has a more mild recess in the lobe to screw head placement... Thoughts? upon disassembly of my own plate it seems to more closely resemble the steadfast style screws............
 

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#15 ·
Working from old memories the adjuster screw mounted on the base plate are not the same as the adjuster screw at the points. The ones at the points are replaceable while the base plate one's do not have a part number. I used to watch for points plates at Swap Meets with one good base plate screw. If careful you can get them out and reuse them.

K
 
#17 ·
I cannot seem to be able to remove the backing plate eccentric screw due to some kind of locking washer holding them in, I attached an img of the washers in question, I dont want to break the plate so any advice or knowledge on this assembly from your experience would be very appreciated..
 

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#20 · (Edited)
Hi Orbweaver88, Hold on, are you saying the eccentric screw for points is riveted in? Kind of looks like the riveted on end is part of the guide system.

I see from eBay photos '71 & 72 points plates are built differently than my '73. The concept is the same, but a different way keeping sub plates in an arc.

My original from new eccentrics look similar to Steadfast. 3/32" offset with ruler placed on the large base to the screw part.

I don't know that it matters that much. If you end up lacking travel for point adjustment or timing adjustment on backing plate, then it would matter.
Don
 
#21 ·
That's funny, I usually don't pry too hard on small assemblies. I will take it apart completely and come to a conclusion whether they are removeable. One member said there's no OEM Part No. so it was not removable from backing plate. I find it comical that no reproduction plates are being produced anymore; at least to my knowledge. +1 on the Steadfast screws looking more like the factory.
 
#24 ·
Hi Orbweaver88, Maybe this will help you find parts that will work good for you. Not a simple subject.

The points plates & points sets changed over the years. My observation is if a newer part/style would fit, Triumph/Lucas quit making the earlier version. It seems Triumph/Lucas modified the plates without necessarily changing part #s. Parts books are not necessarily correct either.... Here's some eBay listings that might help identify what will fit your bike.

Looking at your bike you have one of the early versions of the plate where timing can be set for each points with the sub plate. Your version may... have ended in 1972?? Your points have an eccentric adjuster. Hold that thought as things changed.

This is the version you have. It has riveted on points adjustment eccentrics.
https://www.ebay.com/itm/Triumph-Lu...573205?hash=item4b699ef895:g:KlcAAOSwmFtdULXX

My 1973 was a new version which had all 4 eccentrics replaceable. The points had an eccentric adjuster also. 1973 & 74 parts book is not correct in part # for points.

REMEMBER PLATE PART #S MAY NOT BE CORRECT.

POINTS PART #S ARE CORRECT THOUGH.

Starting in about 1976 the point plate was changed again. You got drop in eccentrics for timing adjustment, but points were changed to an early style where you moved points by putting screw driver into a V slot in points & fulcrumed off a boss that was stamped into sub plate for the purpose of helping to gap points. Study the ebay photos carefully.

Your 1971 & my 1973 points are # 99-0772.
1976 & later part # 99-1266.

eBay 99-0772
https://www.ebay.com/itm/TRIUMPH-65...901686&hash=item51d86b98da:g:KQ0AAOSwHjNWAEeK

eBay 99-1266
https://www.ebay.com/itm/POINTS-CON...461786?hash=item259fc7ce5a:g:qU0AAOSwEzxYOhRy
Plate 99-0768
https://www.ebay.com/itm/Triumph-Lu...742270?hash=item33d7cb133e:g:4t0AAOSwOS1Zuz4Q

Plate 99-1265
https://www.ebay.com/itm/TRIUMPH-T1...720072?hash=item1a868fca48:g:HScAAOSwPx5dqDP7

So any of these 3 versions will bolt up & work. Again you must look at plate version & use points that match plate version.

For $39.99 +$8.00 shipping you can't go too far wrong & use your new eccentrics as needed with this used one.
https://www.ebay.com/itm/Triumph-Lu...573205?hash=item4b699ef895:g:KlcAAOSwmFtdULXX

I would probably not get your style with riveted eccentrics. I would get a newer version. Pretty much only the eccentric screws go bad, so used is a good value. Looking at new plates, you can't really go by part #. You have to visually recognize them.
Don
 
#26 · (Edited)
Replacing the '71 6CA with the 1973 8CA and AAU would be a sensable upgrade in the way of serviceability. Don, thanks for that advice.. Would the duration, dwell, lift be more or less the same as the 6CA in regards to the timing. I don't have the slide hammer, makes for a bit more of an investment. ..and im sure the 8CA has its respective AAU separate from the 6CA mechanical advance.
 
#27 ·
Hi Oberweaver88, There is no reason to change the AAU (cam) unless yours is worn or defective. The dwell, point gap etc is the same as yours.

The much older had a different dwell. Also the cam was shorter. The cam got longer to compensate for when they went to the sub plates for timing. Even so you can use 8CA plate with short cam & it still works ok.

I do not subscribe to using slide hammer to remove AAU. I feel it puts needless strain on the cam bushings. Just get the factory type puller that looks like a stepped bolt with threads near head. Use the part # from your 1971 shop manual as it has unified fine threads. The older AAU has CEI threads, which look very similar, but not interchangeable. Your puller is the same one the '73 AAU will take. I know that as I have one & have used it many times on both years. Again I don't think slide hammer is the way to do it.

I also do not subscribe to smacking it side ways to break the taper loose. Why not just get the proper tool & be done with it? The proper tool assures not damage to exhaust cam or AAU.

Sometimes (often??) the AAU can fit quite tight on the taper. The factory type tool will remove even the tightest. I've removed dozens. Most were tight. I don't think $13.95 will break the bank... This one should work for your year & the '73.

https://www.ebay.com/itm/TRIUMPH-BS...736141&hash=item3d24034f00:g:ZfsAAOSwHoFXwc8c

If you are skilled & understand how the factory tool works, you can replicate the action with a metal rod the right diameter & length & a 5/16 fine thread bolt. Again, if...
Don
 
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