Jumping when cold

my girlfriends px125 (only 3000kms, standard set up) jumps forward when you engage first - but only when it’s cold. after that it’s perfect.

So I left it to warm up before changing to first and but it still does the same thing.

the clutch is fine and well adjusted…the engine hasn’t been thrashed and is quite new

any ideas?

the same sorta thing happens on my t5, only after a cold start, and only when going into 1st from neutral. been like htat since i got a cosa clutch on it 6 months back…

yeah - the oil is correct and changed about 500k ago.
Is it just that the plates are ‚dry‘ to start with and then after just a few changes they’re ‚wet‘ and work ok?

the first change ‚clunk‘ is getting worse so maybe I should change the plates.
But is this normal after 3000k of easy riding?


it is a good idea. Try to change the plates and clutch springs too.
After3000km, it is not normal, but sometimes everything can happen, it is just a question in which % these things happen that we can say it is normal or not. You are in the wrong side of this %


so a month later…
I’ve replaced the clutch plates/springs and changed the oil again, cleaned/greased the gear selector mechanism…and now it’s fixed!

thanks for the advice.

now back to my main problem - tuning my 210!


my t5 does the same sort of thing. in fact the first time you put it in to gear it stalls. every thing is spot on i just think its the plats sticking a bit. how much does it jump or does it crawl?

when you say jumpin do you mean engaging forward motion while the clutch is pulled in or do you mean a clunk,jolt or kickback sensation as soon as firsts engaged as this could be the springs sticking in the cush drive plate. How muh SAE30 have you put in the box ??


is it the engine oil the right grade? (SAE 30)

Other possibilities:

Clutch plates warped
Clutch spring tension uneven
Clutch release mechanism defective.