Epoxy Thread Repair

for those of you that have M.B.S. (multiple bike syndrome) and have the "silver wing" models.
as our sponsors also have supplies for those bikes and they are popular with the "wing" crowd.

Moderators: CYBORG, Oldewing, robin1731, Forum Moderators

Post Reply
User avatar
Earl43P
Silver Member
Silver Member
Posts: 670
Joined: Fri Mar 02, 2012 8:10 pm
Location: Farmington, PA

Re: Epoxy Thread Repair

#16

Post by Earl43P »

I would thread a longer bolt in until it either bottoms out (don't snap it!) or threads right on through, which is what I expect you will find (more thread available).

If the longer bolt bottoms out, measure how much of it to cut off and compare its length to the original bolt.

If you find the longer bolt binding up, don't gorilla torque it, use a bottoming tap instead to chase the unused threads that are likely grungy, causing the bind. Careful again, not to gorilla torque the tap. They are near impossible for a novice to drill through if that thing snaps off.

There is no way I'd do any epoxy thread repair expecting success, even at that low torque.
KTM390A “Hootinanny”
04 ST1300 DDDD (Double darksided daily driver) Sold 4/2022
93 GL1500I Double darksided and SOLD 3/29/20.
99 Valkyrie IS, Fast Black Double Darksided
"Fishtailed, flipped and flung me, but wearing it well". Sold!
82 GL1100 retired DD, needs work.... Sold 3/3/17
User avatar
salukispeed
Platinum Member
Platinum Member
Posts: 1951
Joined: Sun Feb 21, 2010 10:08 am
Location: Oak Forest Illinois US

Re: Epoxy Thread Repair

#17

Post by salukispeed »

Epoxy is a great product and JBweld is a good choice too but at the engine temps expected when running the epoxy material will soften some and torque will become questionable at best.
Honda 72 CL100 sold
74 CB750 K4 nice driver
1966 CA77/305 Dream nostalgic driver
84 GL1200I work in progress
1970 CT 70
1982 GL500 Interstate
User avatar
Sidecar Bob
Honored Life Member
Honored Life Member
Posts: 7631
Joined: Sun Jun 11, 2006 10:14 pm
Location: Kawartha Lakes, Ontario

Re: Epoxy Thread Repair

#18

Post by Sidecar Bob »

I can't remember whether that hole goes all the way through but there is an easy way to find out: remove the screw and try passing something longer through the hole like the end of a wire.

If the hole goes all the way through forget trying to repair it without removing the head because drilling & tapping will put chips into the crankcase, not to mention the helicoil's tang.

I would start by trying a longer bolt as Earl described except if the hole goes all the way through don't run a tap in (it would probably be tapped through anyway).

BTW: That bolt doesn't just hold the thermostat housing bracket, it also holds part of the head and, as such, it needs the correct torque to keep the head from warping. Because of that I would not recommend changing the size of the bolt or even the pitch of the threads.
Mr. Honda ('83 GL1100/Dnepr) summer How a motorcycle evolves thread
The Famous Eccles ('84 CX650EI/VeloUral) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
"A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....
Post Reply
  • Similar Topics
    Replies
    Views
    Last post

Return to “GL 500,GL650, CX500, CX650 forum”