Cam Shaft Chain Tensioner

[Steve Long]

I have a 1978 GS400.
The cam chain tensioner sometimes vibrates wildly back and forth on the knob.
Is it broken or just in need of adjustment?
How do you adjust it?
Thanks,
Steve

[80GS750]

it may just be worn out or loose....

if you need a replacement let me know i have one that will work...

send me a pm if interested

[Billy Ricks]

With the tensioner removed from the cylinder block loosen the lock nut on the left side of the tensioner and back the slotted bolt out ¼ turn. Turn the knob on the right side of the tensioner, which in the Suzuki service manual is called a lock shaft handle, counterclock-wise. As you are turning the knob counterclock-wise push the pushrod all the way back. Keep turning the knob until it refuses to turn any further.

With the pushrod still pushed in as far as it will go tighten the slotted bolt so that the pushrod will not plunge out.

Remount the tensioner to the cylinder block. If the tensioner is not going in turn the crankshaft clockwise slowly to get slack in the cam chain on the intake side of the block.

Loosen the slotted bolt ¼ turn allowing the pushrod to advance towards the cam chain. Tighten the lock nut but leave the slotted bolt loose by that ¼ turn.

While turning the knob counterclock-wise, slowly rotate the crankshaft in reverse direction, counterclock-wise. This causes the chain to push the pushrod back.

Release the knob and slowly turn the crankshaft in the normal direction, clockwise. You should see the knob rotate as the chain becomes progressively tighter. If it does the pushrod is obviously moving forward under spring pressure signifying the tensioner is in good operable condition. If it moves sluggishly or not at all that means the pushrod or the slotted bolt is sticking. If so remove the tensioner from the block again and inspect the pushrod. It could need cleaning or could be bent or galled. Further crank rotation will take the slack out of the cam chain.

[brveagle]

Get a Manual Cam Chain Tensioner and forget about it.

[bwringer]

More info on cam chain tensioners:

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

Yours will look a bit different, but they all function the same.

No one makes a manual cam chain tensioner for the GS400, since they're not a popular drag racing engine... :shock:

Also, sync your carbs.