74birkshire clutch cover

[Mickey Sergeant]

When installing clutch cable I somehow messed up threds on case for access plug.Is this repairable.All help apriciated.

[joe novak]

Hello,  If you are referring to the large, flat, screw-in plugs, with short threads, I know it can be a little difficult to install them correctly.  You likely are not the first and only person to have difficulty installing them.  I find it easier to remove the cover to replace the cable.  Can you determine if it is the threads on the plug, or the threads in the clutch cover which are damaged?   To what degree are they damaged?  Stripped, cross-threaded, or other?   I assume you want to put these parts together again.   I would try to repair the threads in the cover ideally with a thread tap or a bolt of the same thread, and replace the plug with a new one.   If too much metal has been removed, the plug will not fit securely.  I have successfully used tephlon tape to help seal loose plugs.  Since the cable can be replaced by removing the cover, the plug could be epoxied securely into place, or welded.  I would weld from the inside.  I would think that a good brand of epoxy specific to aluminum will do the repair.  Be sure to use a solvent to clean the area of oil before epoxy repairs.  This is not a high-pressure area; it just keeps oil from leaking out the side.   If I remember correctly (it has been 30+ years), the other plug is used for clutch adjustment.  You do not want to damage that plug hole!  Wait for other suggestions before you make your decision on the method of repair.  joe

[Mickey Sergeant]

Checked threads on plug,ok.Would you know size of bolt to use and thread type.I have some taps,nothing that big.May have to purchase one.Thanks again

[garrettccovington]

In 1985, I threw a chain on my 1974(?) XS650 and it cracked the case next to the countershafts sprocket.  I was young and broke (now I'm old and broke) anyways  I layed the bike over removed the countershaft sprocket and seal,  cleaned it up real good with acetone or paint thinner and used some JB weld on.  after it dried a day later, I was able to take a hook scribe, file and sandpaper and reform the area the seal sat in and it worked perfect for years.  You might be able to take some jb weld type epoxy to build up some thread area.  Redrill it and re-tap it.

72 six-day

[joe novak]

Unless you have or can borrow a metric tap, it may be better to not go that route.   Last night, I saw a used cover on Ebay for about $10, which is a really good price.  Shipping was about $10, I think.   Check at Sears hardware store for a tap, or maybe an industrial supply warehouse.  Big taps can be expensive, likely the price of a used cover.  Can you try to correct the threads with a metal sharp pick?  Aluminum is a soft metal (Yeah, that's why it stripped!), so it can be re-shaped, too.   JB is a good idea to fill the threads if you can correct them.  It will make the fit better.

[joe novak]

Hello,  Did you repair your side cover?

[Mickey Sergeant]

Yes I was able to repair by using a dental tool to straighten threads enough to get cap started.Thanks for all the sugestions.
74 Birkshire
allmost completed,three years of hard work