Topic: Clutch engages rough

[John]

Hey guys,
Just finished rebuilding a 1971 cb750 (new bore, rings, pistons, valves, rebuilt carbs etc.) Once it's going, it runs incredible. However getting into 1st - not so great. Right at the start of the friction zone the chain makes a really terrible noise like it's being pulled and released repeatedly (most likely because it IS being pulled and released repeatedly). I have never ridden another cb750 before but it seems like i need to give it too much gas to finally get going. Clutch has new friction plates. Steel plates were examined and cleaned with scotchbrite. Cable is adjusted per manual. Is there a break-in time for new friction plates? Should i replace the steel plates? Maybe need to take it apart and soak the friction plates in oil for a night. Or is this possibly not clutch related but an idle or tranny issue? Any thoughts?
Many Thanks,
john

[Einyodeler]

How old are the chain and sprockets.If you have some rusted links on your chain it will ride up on the sprockets and display the same symptoms.

[John]

Thanks for the suggestion. The sprockets are new and the chain has not been used, but unfortunately sat in a corner of the garage for a year and a half while i finished this thing. So, it has some rust. I'll try and ride it and get it warm then lube and let it sit for a night - see if that helps. I still feel like it is somehow clutch related. Any one else experienced this kind of lurching take-off?
john

[Bob Wessner]

Einyodeler,

I love the second line of you signiture info. 

[Einyodeler]

Hehe....yeah,it kind of makes you wish you had long ears

[Bob Wessner]

We have a basset hound, so she is my alter ego in this regard. 

[MRieck]

I think the noise you hear are the primary chains slapping up and down. Yes...it does sound awful. Did you soak the friction plates before installing them. An upgrade to the later clutch setup (with the riveted spring loaded steel plate) helps reduce this as well as makes shifting much better.

[cben750f0]

i have a similar problem mate, but mine only plays up when you are trying to crawl along in traffic,,, you know when you are going to slow to have the clutch out, so you are slipping,it to just keep rolling alone.... gets a real shake up, so i have to pull the clutch, and give it more revs and let it out... and b4 you say it , its not stalling, do these clutches have damper units in them?... peace

[MRieck]

i have a similar problem mate, but mine only plays up when you are trying to crawl along in traffic,,, you know when you are going to slow to have the clutch out, so you are slipping,it to just keep rolling alone.... gets a real shake up, so i have to pull the clutch, and give it more revs and let it out... and b4 you say it , its not stalling, do these clutches have damper units in them?... peace

Yep- exactly when it happens the most. What is happening is the clutch is grabbibg, slipping a little and grabbing again. This causes the primary chains to"bounce" up and done. There is a damper unit built into the primary sprocket but with age it gets very stiff and doesn't cushion very well.

[cben750f0]

well it looks like i will have to live with it then ....thanks for the eply..peace

[MRieck]

You can replace most of the clutch components with pieces from an F2 or F3. You'd need the parts from a junk bike as most of the pieces need to be replaced and the cost would be very high otherwise. It does make a nice difference- I did it to my 75F.

[cben750f0]

yeah maybe after i get the pods tuned... am busy with that atm... though am getting really good at taking tha carbs out now... ..thanks for the help mate...BTW still cant talk my missus into a ported head... she just doesnt seee the need.... wemon!!!     peace

[mcpuffett]

hey ben you could always try the    it;s broken and i need this part routine    lol mick.

[MRieck]

 

[cben750f0]

would rather not go there, things like that have a habit of commin round and bitting you in the A$$... ..peace