Any ideas on the cause of a knocking sound on the LOWER LEFT of the engine. Ive replaced the CCT by the way.

The sound is more noticeable when the engine warms up.

The bike is a `91 F2 with 62,000 km which is about 37,000 miles.

 

Wow. 49 views and not a single comment?? No clues?

 

Could be a lot of things, unfortunately, none of them are going to be good. Since the valvetrain/CCT is on the right side, I'm thinking you might be hearing a con-rod.

Other (cheaper, easier to check) things - maybe something's coming apart in your stator assembly and is knocking around. Possibly your water-pump is seizing up or the bearing for the impeller is shot.

Just throwing some ideas out there.

 

Mine still runs fine, it's just that it gets noisy once warmed up.

 

meh, fill it with oil and run it until it blows up. Its a 20 year old bike

 

Good point!

 

Go with the stator first. Check the small things first. Worst case, drop the engine and crack it open.

 

What is the Stator?

 

Stator is the generator/alternator assembly for the bike. It is under that cover on the left side of the motor.

You can find the service manuals here:

for the F2 - http://www.stephygee.com/F2manual.zip

and the common svc. manual - http://www.stephygee.com/hondacommon.zip


Oh - and my 2 cents, sure it's a 20 year old motor, but they aren't the easiest things in the world to find replacements for with mileage that isn't going to warrant a teardown and inspection. Then you have to ship it, then you have to find someone to work on it for you it seems. Why not just put that money into diagnosing and fixing what you have.