Topic: Clutch Question. Thoughts?

[BenelliSEI]

Last week I installed a new chain and sprockets on my 1973 cb750K. My son usually rides this bike and the last time we rode together for a few days, I spotted some very worn sprockets…..

Yesterday I put +100 miles on the bike. It runs great but when starting off from rest there is a slight “judder” and hesitation. When Ihad the Lester wheel off last week, I checked the rubber snubbers in the cush drive and they were dry and perfect. I suspect this poor engagement is caused by the cush drive behind the clutch basket? Anybody confirm my suspicions?

I’ll probably pull the clutch apart this week to make sir there is nothing falling apart in there, just incase…….

[MauiK3]

Could it be the oil in the engine?

[BenelliSEI]

Could it be the oil in the engine?

Honda GN4 10W-40. Same as all my other bikes……

[HondaMan]

That bike is the color mine was when I bought it! Nice condition!

[CycleRanger]

It could be the basket but that's not the first thing I would suspect.
Could be a couple of weak clutch springs or slightly warped or sticking steels or plates.

[BenelliSEI]

It could be the basket but that's not the first thing I would suspect.
Could be a couple of weak clutch springs or slightly warped or sticking steels or plates.

I hope you’re right! Maybe a broken lifter plate? I have a few new sets in my stash, so will pull it all down when it cools off a bit here!

[BenelliSEI]

That bike is the color mine was when I bought it! Nice condition!

The engine has never been opened up in this one. It runs so well I rarely touch it! Will pull apart the clutch next.

[scottly]

I suspect this poor engagement is caused by the cush drive behind the clutch basket? Anybody confirm my suspicions?

There is no "cush drive" or dampers behind the clutch basket.
http://forums.sohc4.net/index.php/topic,205513.msg2322391.html#msg2322391

[HondaMan]

K3 era: look closely at the friction surface of both the top (pressure) plate where it contacts the cork plate, and the similar surface at the back (hub) of the stack. In the early K1 and again in the early K3 bikes, these could warp a little bit (they were still largely hand-cast parts at the Old Factory). It will be obvious if this is the case: a portion of the surface will show wear marks and a portion won't.

The New Factory bikes were receiving nice injection-molded parts by then.

[BenelliSEI]

Thanks for all the clarifications! I will post what I find. The engine is tuned and the carbs are perfectly sync’d. Definitely a clutch issue…..

[MauiK3]

I put in a lifter plate made by someone here on the forum, it's pretty nice, forget who made it.

[BenelliSEI]

I put in a lifter plate made by someone here on the forum, it's pretty nice, forget who made it.

I have a couple of NOS ones that came with the stuff I bought from Flybackwards….
No excuses.

[Honda Hansel]

There is a cush drive on the inside of the primary drive sprocket
The cases need to be split to get them out
Cycle X makes a kit for that problem
If my memory serves me right

Just put in a new EBC clutch kit in my beloved K7 and works good now
Plates and springs $ 117.00 Ca

Honda Hansel