Topic: Shudder on takeoff after cold start (clutch?)

[zabzob]

I've got a 1975 CB750.

When I start it in the morning after it has been sitting all night, I sometimes get violent shuddering after I let out the clutch. This is after pushing the bike away from my building to start it so as not to annoy the neighbours, with the bike in 1st gear and the clutch pulled in. I figure this would loosen up any stuck plates. Doesn't seem to help.

This does not happen again at any point during the day. I don't think it is the front brake. No appreciable drag when I push it out to the curb. Last oil change was Saturday. It happened again this morning.

Is my clutch going? Just need adjusting?

[Sniper X]

How many miles are on the clutch? And yes it is the clutch. Try adjusting it to factory spec by the adjuster on the motor and handlebar and see if it goes away first.

[HondaMan]

If I understand your "morning startup" explanation, you are drying out the oil between the clutch plates by pushing it with the clutch pulled in and rolling it with the engine off. That first shudder is dry plates. This can be real hard on the cork: try just rolling the bike in neutral instead?

[zabzob]

HM, I will try rolling it out in neutral over the next week or two and will see if it's still happening.

Sniper, not sure how many miles on this clutch... it was a Barnett racing clutch that the PO installed an unknown number of miles ago. If simply the passing of time can be a factor in clutch deterioration, that might be it. This clutch is at least 18 years old.

[HondaMan]

HM, I will try rolling it out in neutral over the next week or two and will see if it's still happening.

Sniper, not sure how many miles on this clutch... it was a Barnett racing clutch that the PO installed an unknown number of miles ago. If simply the passing of time can be a factor in clutch deterioration, that might be it. This clutch is at least 18 years old.

There's a clue...the Barnetts often shed their cork adhesive after about 8-10 years. This makes the cork become uneven and wrinkly. If the 'neutral roll-out' doesn't solve it, a new set of friction plates might be in order.