Help - Clutch problem?

[panteleimon]

Hi.

Getting the bike back on the road after a few years of "temporary" sitting.
(NC30 & I'm just learning about the maintenance as I go.)
Basic service done (oil, filters, plugs, cleaned carbs) & bike starts on the button, warms up fine. (phew.)

However, this is with the clutch lever pulled in (purrs normally), & when I release it, the bike starts to stutter & temp goes up.
So, I'm guessing it's a clutch problem & have bought new plate set, with the plan to tackle changing it with the help of the video on the site.
But, just want some advice to check that this is indeed the problem (plates sticking?), or whether the diaphragm spring needs changing, or if there is something else it could be? Anything else I need to do or check?

Also, fan doesn't seem to be kicking in when temp goes up. All wiring seems connected. What to check?

Cheers for the help!

[magg]

I believe you have an earth problem, not a clutch problem. Pulling in the in the clutch lever provides the missing earth link, which is removed when you release the lever. Does the neutral lamp illuminate when in neutral? Does this problem occur when in neutral, clutch in/out? Do you have a multimeter?

[panteleimon]

A few more details to hopefully clarify.
Happens in neutral and in gear.
Neutral lamp does illuminate (& off in gear).
Bike doesn't cut out, just kind of judders / stutters as clutch lever let out.
pull the lever back in, even from fully out, & all is well again.

Have multimeter but hate electrics.
Saying that, did manage to locate prob to reg rec rather than batt or alternator on previous bike.
So, can find my way around with some instructions.
How to diagnose an earth prob?

Thanks!

[magg]

"Judders/stutters" as in misfire, does the problem occur when the clutch lever is released and bike in neutral?

[panteleimon]

"Judders" is probably a better description.
Doesn't seem to misfire.
Rather, seems like bike engine santa to get going but it's getting caught/stuck/held back. But like severe case of being in too high a gear at very slow speed.

A talk through:
Key in & on. Neutral light on with bike in neutral. (Off if select gear, all as normal).
Holding clutch lever in.
Starts on button with choke, our even without.
Engine purs like a sewing machine as normal.
Drops revs as normal when choke off.
Will rev all the way up, with clutch lever still held in at this point, all sounding perfectly normal and silky smooth.
Now the problem:
Still in neutral, slowly (or quickly) let out the clutch lever.
Now the bike is juddering, like wanting to go somewhere but can't.
Back wheel starting to turn a little up on stand.
If try to give it a little gas, judder gets worse.
Temp starts soaring.
Will go off scale unless switch off or pull clutch lever back in.
(Aside, fan doesn't kick in.)
Settles back to normal with clutch lever pulled back in.
Doesn't stall or cut out.
Turn bike off.

Hope that makes sense.
Wondering if it could be the clutch diaphragm spring, before I dismantle everything.

Thanks again & appreciate any other advice.

[magg]

What happens if you start the bike on the side stand in neutral with clutch lever released?