Motorcycle Repair: 1982 honda magna v45, honda magna v45, 1982 honda magna

Question
how common is a problem with the cam chain and tensioner on the 750cc v45 motor? and what does it sound like when it is a problem.  My bike is making a noise that almost sounds like someone is beating on it with a hammer at idle speeds from time to time.  Almost like it is chattering in between gears.  It is also making a very prominent ticking sound at idle that seems to be coming from the top part of the motor under the gastank/seat, not from the part of the motor near the radiator?  My odometer reads only about 13,500 miles, I have only owned the bike for about 700 of those miles put on in the last two weeks or so. The bike did not run when I bought it due to bad gas in the carbs. I figured with low miles the internal workings of the engine should be in good shape.  Also, why are there so many variations in the instruments on this vintage of machine?  I have seen speedometers that go to 160mph while mine only goes to 85mph.  I hope that is specific enough, but I would be more than happy to go out and start it up and listen if there is anything I can do to better describe the noises.  Thankyou, craig modean  email: seapee2003@yahoo.com

Answer
Hi Craig,

Excessive valve clearances causes tapping noises. This is normal and not harmful. Zero or not enough valve clearance is harmful.

Consider checking valve clearances. If out of service limits, adjust clearances accordingly.

You'll find links to the service manual below.

Read about the delima with early Magna heads here:

http://home.earthlink.net/~wrenchtwister/V4hist.html


These are additional Magna resources:

www.sabmag.org/maintenance.htm

http://thepit.shacknet.nu/honda/

www.magnaownersoftexas.org/specs.htm


I can't explain the variations in instruments. Has techs wondering, too.

Respectfully,
Mark Shively