Expert: Bill Silver - 9/29/2006

Question
The masterlink on the timing chain on my 71 CB175 broke.  I got the chain and the link pieces out of the bottom of the engine.  First, is the chain supposed to have a masterlink?  Second, is there an easy way to put the chain back in place without tearing the bike apart and how do I put it back on and adjust it.
Thank you.

Answer
Dustin,
First question: Yes, it does have a master link. It probably broke because the tension wasn't maintained on the camchain by a properly adjusted tensioner.

Second question: NO, there is no easy way to put it back.
Go to: http://www.powersportspro.com/partsfish/login.asp
sign up, log in and select HONDA MOTORCYCLES, then CB200T (close match to the 175s), the camchain tensioner. The chain specification is: (DID219T-86L).

You probably have bent valves from the chain flying loose when the motor was running. The valves and pistons usually come together at that moment and the valves bend when they hit the piston crowns.

Pull the motor, pull the cylinder head, check the valves and pistons for damage. You can turn the head over and check for leaks at the valve seats by pouring some solvent into the combustion chamber with the spark plug still in place and the valves are closed. If it holds fluid, then the valves are okay. At that point it is wise to decarbon the valves and the pistons if they are not excessively worn. Check the rings for excessive gap and the cylinder walls for any ridge, that occurs from wear. You may have to rebore the cylinders or just clean the pistons and put in new rings of whatever size the pistons are sized at now.

Good idea to get a manual from Ebay or other sources, so you can see what else is involved in rebuilding the top end. If the head is damaged from the bent valves, you will have to get good used parts and try it again. If the camchain was left to flop around inside for a long time, there will be grooves in the cylinder block tower hole. That aluminum is now down in the oil pump screen and inside the centrifugal oil filter, so clean out everything before you reassemble it and get it running again.

Bill Silver