Questionhello bill, i'm hoping you can help. i was adjusting the cam chain on my '68 cl175 and all was going well. upon retightening i got overzealous and, yup, broke the adjustment bolt which is now in two pieces with a good portion stuck in the hole there. i'm a novice, what can i do? is it harmful to drive the bike like this ( i heard the chain can go slack and do some serious damage to the engine. any advice/help would be appreciated. thanks.
AnswerMichael, Welcome to the world of vintage Honda motorcycle repair!
Unless you happened to have had the camchain in the fully tensioned mode, before you snugged down the bolt, then you will have to pull the motor and remove the cylinder head to access and hopefully remove the tensioner bolt.
You can check camchain tension by putting a tight fitting wrench on the end of the crankshaft rotor bolt and rocking the crankshaft back and forth. If you feel a little 'dead spot' between the changes in directions, then probably you have a slack chain. You can also check it by removing a valve cover cap, turn the engine over until the valve is partially open, then turn the engine backwards slightly and forwards, watching/feeling that the crankshaft motion is directly related to the valve motion with no pauses in between. If that is the case, then you can run it for awhile as it is, but the right way to handle it is to pull the motor and remove the cylinder head so you can access the end of the bolt either with an EZ-out or find a shop that has an EDM machine to burn out the bolt without harming the surrounding metal.
Historically, E-Z outs are generally not a good option for tensioner bolt removal. It is a tiny bolt, but once they are jammed into that threaded hole and break off, they are very tough to back out again.
Bill Silver
