Topic: stripped carb hole

[73hutch]

when i rebuilt this set of carbs three years ago, i managed to strip the hole that the carb bowl screws into. i was told by the guy at the shop that i buy parts from to get a self tapping screw and that should work. i ran with it for a while but it always leaked a little. i haven't used those carbs in a year of so and i'm getting ready to put them on another bike. i unscrewed the bowls the other day and now the self tapping screws won't hold it at all. my question is: is there anything i put in the hole (jb weld?) to create a better hole to screw into? i do have a set of carbs to use for parts. so if nothing else, i can replace the whole carb. (i guessing that what you folks are going suggest i do).

[punch455]

If there is enough space around the hole, maybe just tap new threads.  Do it once and it will hold just as long as original.  Take one of the original screws to a hardware store, find out what size it is, and buy a tap the next size up, and a new screw to fit the new threads. Your only other real option is to get a longer machine screw and put a nut on the top and tighten the two together.

[Soos]

Have you looked into having a helicoil put in there?
Not sure there is enough meat for a timesert though.(is that the right name?)

Or (hate to mention this) tap it bigger.... might have to enlarge the hole in the float bowl though. Might weaken the float bowl, or the head might be to big, not allowing you to tighten it all the way.... But it's an option I guess.


I dunno about JB weld holding threads... i've always tried to shy away from that stuff unless I am seriously pinched for time or money.
Not saying it will not work... just very little experience with it.

I'm guessing you either have a '79/80 cb650, or a '77/78 cb750??



l8r

[Soos]

Your only other real option is to get a longer machine screw and put a nut on the top and tighten the two together.

Thats something I hadn't thought of, not too bad an idea as the hole is on the outside carb at least.



l8r

[bender01]

try this .
 http://forums.sohc4.net/index.php?topic=37129.0
  Worked great for me.

[73hutch]

If there is enough space around the hole, maybe just tap new threads.  Do it once and it will hold just as long as original.  Take one of the original screws to a hardware store, find out what size it is, and buy a tap the next size up, and a new screw to fit the new threads. Your only other real option is to get a longer machine screw and put a nut on the top and tighten the two together.

i'm liking this idea. going to look and see it will work. thanks for all the advice! BTW it's a 78 550k.

[Duke McDukiedook]

JB weld and gas do not mix well. Just ask my old truck gas tank.

[pablo78cb550]

i heli coiled a few of my float bowl screws. no problems.

[cb750fbomb]

What happened to me is the soft alum. threads stuck to the screw that were used. I could unravel them with my fingernail. I got screws that were a little longer and it used threads that the old ones weren't using past the stripped threads. may be I just got lucky, but you can try it.