whats the knob in the middle of the motor under the carbs for?

[kilog55]

so this has puzzled me for some time now is it a adjuster for something like the timing/cam chain? or what

[Bribird]

timing chain tensioner.

[Billy Ricks]

And don't turn it unless you're prepared to pull it off and reset it.

[imnowhooked]

so this has puzzled me for some time now is it a adjuster for something like the timing/cam chain? or what

I have wondered this for some time, just never thought to ask! Thanks for asking the question Mr kilog55!

By the way...what exactly would happen if it did get turned??

[Steve]

By the way...what exactly would happen if it did get turned??

Turning the knob retracts the tensioner. If you do this while the engine is running, the chain can get loose enough to skip a tooth ... or two ... or three.

No harm in turning it while the engine is stopped, to verify that it is still free to move, but don't do it while the engine is running.

.

[bwringer]

Stripped! Naked! Cam chain tensioner photos!

http://bwringer.com/gs/camchaintens.html

(Also, info on how to purchase and replace the seal and o-rings within this little mystery.)

[Billy Ricks]

The problem with turning the knob is if for any reason the pushrod is binding and you don't realize it then you have a problem. Binding probably isn't very common, but if you turn the knob you have to be prepared to service the tensioner for peace of mind. When carbs are off a bike it's really a pretty good idea to pull the tensioner off and check its operation.

[Zooks]

Whatever you do, don't touch that knob !!!!!

[kilog55]

lots of good info there glad i asked thanks

[donimo]

haa, I was gonna ask that soon myself...

[imnowhooked]

lots of good info there glad i asked thanks

I too am glad you asked! Many times I have said to myself..."I wonder what happens when you turn this knob?!?!..(no smart comments please!!) I am just glad I was able to control myself as I don't usually wear a parachute when I am on the bike!

Thanks for all the info everyone..very helpful!!!...As for the provocative Stripped! Naked! Cam chain tensioner photos Mr bwringer....I only read the article!!

[nisom512]

Whatever you do, don't touch that knob !!!!!

AHAHAHAH I laughed really loud at this. the bad part about it is I was in a compuuter lab at school...HAHHa

[mriddle]

I just pulled my 83 out into the driveway and started it.

Rode down the drive and back and on the return I heard a strange sound that was related to rpm.

Shut of the engine and got off to find the knob from the Cam Chain Tensioner laying on the engine block .. loose .

The engine was running before I stopped but I did notice it backfired (which I had never noticed it do before).


What have I done to my poor bike ?

[Hammered]

Stripped! Naked! Cam chain tensioner photos!

I feel kinda dirty and used. But in a good way.