Honda CB450 can chain tensioner help

[Derek4Real3]

so after a quick ride today i was going over the whole bike and noticed that there was something moving in and out, in the hole of the cam chain tensioner. Now call me stupid but i thought ive read up and done my homework on this motor but i dont recall this at all and its making me nervous to rev into the higher RPMs.
heres a pic to help

Thanks

 

[Joe]

Once the chain tension is set it is suppossed to be locked down with the bolt there so far as I know.....

 

[Flugtechnik]

yeah, that ain't supposed to move while the bike is running.

The tensioner is spring loaded with a wheel on the end pushing on the cam chain. The way it is supposed to work is that as the cam chain stretches from use, it becomes loose. As part of your periodic maintenance you loosen that bolt at the top which allows the spring to to push the wheel in further resetting the tension on the chain. Then you tighten that bolt back up to lock it in place. The spring only has enough force to set the proper tension when the bike is not running. That thing you see moving is the plunger that the wheel and spring are on.

Do not ride your bike with this loose. You could loose your cam chain. If that happens, you will loose your valves and possibly your pistons. If tightening the bolt at the top does not keep the plunger from moving, you will probably need a new tensioner. Used ones are fairly cheap on ebay and it should be easy to replace.

Tighten the bolt, then tighten the lower nut. The lower one is the lock nut that keeps the bolt from backing out due to vibration.

 

[Joe]

Just to add one thing, the motor is supposed to be in a certain position before loosening the bolt and setting the tension. Consult a service manual to learn the procedures.

 

[Derek4Real3]

heres what it said to do and what i did.

remove the alt. cover (drain oil)
remove spark plug on left cylinder
turn motor by the crankshaft bolt counter clockwise until TDC, then turn 90* CC
loosen adjuster lock nut ( i even had to loosen the adjust to let the push rod back in)
tighten down the adjust, then tighten lock nut.


since the oil was drained i replaced the clutch springs with upgraded "race" springs that i had been putting off, i needed a oil change anyways.

;D

 

[Flugtechnik]

huh? you don't need to drain the oil to remove the alternator cover.

But if you wanted to remove the clutch cover as well to get those springs in there, then that's cool.

 

[Derek4Real3]

huh? you don't need to drain the oil to remove the alternator cover.

But if you wanted to remove the clutch cover as well to get those springs in there, then that's cool.

when i unscrewed my alt cover oil poured out............. ???

 

[Joe]

If you lean the bike to the right a little it will not come out. A little will come out when you first remove the cover then it will stop. If you had it on the side stand it would make it worse. There are timing marks on there to be used with a timing light, so the cover has to be removed and running to do that. I like to support mine by a strap from the ceiling and lean it to the right a bit while running it with the cover off. I also stuff a towel under the open cover to catch any oil that is there to keep it from dripping all on the bike and floor.

 

[Derek4Real3]

If you lean the bike to the right a little it will not come out. A little will come out when you first remove the cover then it will stop. If you had it on the side stand it would make it worse. There are timing marks on there to be used with a timing light, so the cover has to be removed and running to do that. I like to support mine by a strap from the ceiling and lean it to the right a bit while running it with the cover off. I also stuff a towel under the open cover to catch any oil that is there to keep it from dripping all on the bike and floor.

oh ok, it was on its side stand and it has more lean then suposed, well either way im glad i changed the oil and it got me motivated to do the clutch springs.

 

[Flugtechnik]

Joe speaks rightly