1970 Sportster Primary Cover Finish

[chuckthebeatertruck]

I thought the last sand cast sportster covers were on 1967 and earlier. I believe the multi ribbed covers were die cast.

There are two XLH "sand cast" covers; 1957-66; and 1967-70.

1971 saw a new clutch system which resulted in a new primary cover. Externally, it resembled the earlier "ribbed" cover from 1967 to 1970 but was a die mold AND set up for the left side clutch actuation that went with the wet clutch system introduced in 1971.

[chuckthebeatertruck]

Chuck, I looked at the website and it does not mention any temperature ranges. I suppose a call or email to the company would be in order. Perhaps it would yellow under high heat.

It's not that it would yellow -- its more that coatings which have a lot of self leveling compounds tend to "smoke off" during the first few uses on an engine or on motor/trans covers subjected to full case heat. Then, on a primary, they also get all sorts of rubbing from your boot, wiping up oil spills, etc. All of this has had a tendency in my experience to accelerate "striping" on the part where some bits age or discolor faster than others. To me; that looks a LOT worse than if the whole thing was just left to age at once.

That's why I was asking whether you had an personal experience with the product in a similar application.

I've found stuff that keeps an alloy pontoon boat shiny or your polished fork sliders shiny doesn't quite work as well on constantly heat cycled parts.

[DEEBS47Chief1991]

Right. I think that stuff would be better used on fork sliders.

[billpedalino]

AFAIK there was no protective finish applied to the covers in 1970/71.

My personal favorite "protective coat" is really a cheat. After you get the cover very clean, take a paper towel or rag dipped in Aluminum (not silver) rust oleum or tremclad. Very lightly rub the aluminum paint into the surface. Bake at 250-300 for 90 minutes. It will look like fresh alloy for many years to come and is very easy to clean up.

I like your 'cheat' suggestion and started looking for Rust Oleum heat resistant aluminum paints. I think the closest would be what I've copied below and I'm curious if this is the paint that you used. This would have to be sprayed onto the rag and lightly rubbed onto the surface. As for Harley coating the primary covers; who knows!?! Mine has a yellowed coating, but as we all know, they were often inconsistent in these matters... So, we're probably both correct.

[chuckthebeatertruck]

I don’t use high temp, just plain old aluminum

https://www.amazon.com/Rust-Oleum-77...435176418&th=1

ive had the same can the better part of a decade. Several bikes treated this way have 3000 to 20000 miles on them. The cases and covers still look new with just a wash.

when applied very thin with a rag or paper towel and baked, the paint pretty much doesn’t want to come off. Our goal is to deposit the thinnest possible layer and the aluminum powder in the paint does all the work for us.

[billpedalino]

I don’t use high temp, just plain old aluminum

https://www.amazon.com/Rust-Oleum-77...76418&th=1

ive had the same can the better part of a decade. Several bikes treated this way have 3000 to 20000 miles on them. The cases and covers still look new with just a wash.

when applied very thin with a rag or paper towel and baked, the paint pretty much doesn’t want to come off. Our goal is to deposit the thinnest possible layer and the aluminum powder in the paint does all the work for us.

I glass beaded the original coating off of the outside surface of the cove and then polished the ribs, but not too much in order to resemble the polishing that the factory did. I then glass beaded the outside surface only using No. 10 glass beads (from TP) which were pretty sharp and cut well This gave the substrate a good profile. I then bought a quart can of the regular Rust Oleum oil-based enamel and dabbed/wiped it on with a paper towel. and wiped off all excess with a dry paper towel. The cover looks very similar to new - maybe a little more whiteish. It's in the oven now and so far, the result looks promising. Thanks for the suggestion!

[billpedalino]

Installed Cover....

[chuckthebeatertruck]

That is almost too clean!

[billpedalino]

That is almost too clean!

I know, right! But it's close. The original finish had a little more grey, but I've invested enough energy into this. I hate to use the expression, but in this case, it's 'close enough'. Thanks again for your suggestion - with a little patience and trial-and-error, it worked out very well.

[chuckthebeatertruck]

I wonder if the brightness is due to the beading just before you dabbed it. I've generally not beaded the outsides, but rather washed them first in naptha, second in really hot detergent, and finally with MEK or acetone before I would dab them. I suspect I started with a more "grey" surface and hence a little more "patina."

I also learned to get thinner and thinner with the dabbing . . . but that's one of those things you can only judge in person. Photos make everything look a bit different than in reality.

The nice part is that from this point forward, your fingerprints won't show in that nice beaded surface. You can just wipe them off with a rag -- or if they really get crusty - a little WD40 on a rag does a great job. The rustoleum, when baked, becomes incredibly durable and solvent/oil resistant.

All in all, I find many uses for the aluminium paint. From "restoring" rusty cad spokes to coating cases, I find it hard to beat for an easy to apply and use coating.

[chuckthebeatertruck]

Here's a question, not a nit-pick.

When I am looking at your photos of the primary, a few things jump out at me which I"m curious about given your long ownership of the bike.

First; the lock washers under the cylinder base nuts. Have those been there since 1973? I haven't seen lock washers on cylinder bases and don't see any in the parts catalogs I have on hand through 1976.

Second, the chrome foot rest and chrome brake lever. I had thought those were only cad in 1968-70. Were these part of a dress up kit?

Third, the chrome motor mount bolt. I've only seen cad from the factory and am curious if those were also present when you bought the bike in '73.

I'm also used to seeing the case hardware (like the top center bolt) in cad for 1970, not parkerized. I have seen the timing hole plug in both cad and parkerized, so I'm not entirely sure which is correct.

Thanks for indulging my curiousity

[billpedalino]

Here's a question, not a nit-pick.

When I am looking at your photos of the primary, a few things jump out at me which I"m curious about given your long ownership of the bike.

First; the lock washers under the cylinder base nuts. Have those been there since 1973? I haven't seen lock washers on cylinder bases and don't see any in the parts catalogs I have on hand through 1976.

Second, the chrome foot rest and chrome brake lever. I had thought those were only cad in 1968-70. Were these part of a dress up kit?

Third, the chrome motor mount bolt. I've only seen cad from the factory and am curious if those were also present when you bought the bike in '73.

I'm also used to seeing the case hardware (like the top center bolt) in cad for 1970, not parkerized. I have seen the timing hole plug in both cad and parkerized, so I'm not entirely sure which is correct.

Thanks for indulging my curiousity

Chuck - How Observant of you! You asked, so I'll respond with this long-winded diatribe:
Of the eight Harley's that I own, four of them are either restored, or being restored to 'judgable' condition, three are newer bikes, and then we have the subject 1970 Sportster, which has its own story.
As I've previously stated, I bought the bike in late '72 from the original Owner, who bought it from Gene Baron's dealership in Babylon New York. I knew the original purchaser and knew Gene quite well, as I worked for him off and on. So, I've known this bike since it was new.
When the original owner sold it to me, it was burnt up; the result of a carburetor fire. I paid $750.00. I was in my early 20's and also owned a 1964 XLCH. So I thought that also owning a Stroker would be fun. So, I disassembled the motor and installed the popular Dytch stroker kit (3-1/4" x 4-5/8") and all the associated go-fast stuff ,thus making it a 77" stroker. It was fast...
I Also did what we all did at back then; I paid homage to the chrome Gods and chromed most of the important parts, until my funds ran out. If memory serves, I believe there are also 1-1/2" extended fork tubes too, so I'll have to obtain the stock, assembled fork dimensions and measure them to be certain.
Finally, when the motor was apart, I decided to convert it to kick and electric start to give my leg the rest I thought it would need in kicking a stroker. This turned out to be unnecessary.
Now, here we are, 53 years later and I decide to undo all the changes that I affected in my youth and bring the bike back to near-original. However, I also decided that a couple of things would remain as a reminder of my younger and wilder years. One of these remnants is the chrome plating that you observed. Also, the cam cover shows the partial cut-out for the previously used Prestolite electric starter motor.
I intend to display the bike next year at Oley as a 'Period Modified', as the paint wont be back for a while. I've attached some progress shots and , as you can see, the bike is otherwise complete.
I'm sure that the judges will look upon the remaining aberrations with distain, and I certainly understand why. But this bike is built for me as a physical touchstone to who I was back then, when I was 25 and knew it all, I won't change a thing.
Thank you for looking so closely, and thank you for enduring this diatribe!

P.S.: I always install lock washers on Sportster cylinder base nuts. You're correct - they weren't installed at the factory. It's a fixation I've had since I worked in the business and had to change so many early Sportster leaky cylinder base gaskets...

[chuckthebeatertruck]

Thanks for indulging me and sharing the story. I like hearing stories about long-owned bikes and what has or has not happened to them.

I was smiling at your stroker and electric starting comments. I only have an electric starter on my 86" stoker (3-3/8 by 4-13/16). The starter works fine -- but the bendix clutch lasts less than 400 miles at a crack ;-) I'm likely to install a tech cycle starter this spring. I don't mind kicking the bike as it generally is a 2 kicker from cold and 1-2 from hot; but they are REAL kicks ;-)

I ask hardware questions because how a bike is put together is WAY more important to me than if it conforms to showroom stock. When I see something unusual; I'm going to ask after it. If lock washers have solved an issue for you; I'm all ears and like to file that info away in the back of my brain.