Topic: Spark Advancer Bolt sheared off - Need Advice! 1972 CB350F

[midnightrider]

Hi guys,

The bolt that holds my points plate and spark advancer in place broke!
(The bolt is Part #95801-06055-00 for reference...part #15 in the parts fiche drawing at the following link)   
http://www.hdlparts.com/fiche_section_detail.asp?section=121141&category=MOTORCYCLES&make=HONDA&year=1972&fveh=2900


It broke off about 2/3" to 3/4" behind the spark advancer, so extracting without fouling the threads would be a miracle...BUT, this also means that there is 2/3" to 3/4" of threads for the remainder of the bolt to bite on to.
I'm thinking at this point that I may just try to reassemble and tighten down with what is left of the bolt (leaving the broken off piece in there) and hope that it works? 
Any other suggestions?  I'm open to any and all.
Thanks.

[midnightrider]

If I do end up trying to make it work with the existing broken bolt - what type of thread locker would you recommend?  Ideally I would like something that will help it hold with less threads biting than it is designed to hold with, but would still like to be able to remove it if I need to.  Any ideas?

[scondon]

Try Blue Loctite. Add a thin lock washer for spacing so that you're not bottoming out on the broken piece left inside. There is not a lot of torque needed on this bolt, you just need to keep it from spinning out. If it's bent, or spinning off axis then you'll want to do it right and replace it.

[midnightrider]

Try Blue Loctite. Add a thin lock washer for spacing so that you're not bottoming out on the broken piece left inside. There is not a lot of torque needed on this bolt, you just need to keep it from spinning out. If it's bent, or spinning off axis then you'll want to do it right and replace it.

Thanks scondon.  Just for reference, here is a picture of how much thread area that I have left:



How deep is the thread hole?  Am I going to need to worry about the broken-off piece moving around in there?

[scondon]

If the end was so seized in the threads as to break the bolt, then I wouldn't worry much about it moving around. Looks like you have plenty of thread left to secure the bolt well. This is one of those "it's worth a shot" fixes, and it looks like you have a decent chance of success. The alternative involves a lot of work 

[midnightrider]

If the end was so seized in the threads as to break the bolt, then I wouldn't worry much about it moving around. Looks like you have plenty of thread left to secure the bolt well. This is one of those "it's worth a shot" fixes, and it looks like you have a decent chance of success. The alternative involves a lot of work 

Thanks for the help.  I'll let you know how it goes! 
I have some ProSeal Thread Lock that Im going to use.  I hear that it's just as good as Loc Tite

http://www.grainger.com/Grainger/items/3HHH9?cm_mmc=Google%20Base-_-Adhesives,%20Sealants%20and%20Tape-_-Thread%20and%20Gasket%20Sealants-_-3HHH9