Rvf400 clutch ptoblems

[balen1]

Hey guys, having problems with my clutch. Seems to slip in high rpm past 3 gear. Was wondering if anyone has had similar problems and what I need to do to fix it?

Also after a ride yesterday on a windy road moving up and down through the gears. When I got to the top of the hill and backed off, the bike suddenly bogged and turned off. I waited 5 mins and started it up and it seemed fine but the transmission sounds noisier when coasting. Any one know what's going on and why it turned off?

[CRM]

howdo
ok when you say slipping, if you mean at high rpm and a proper slip to the red line then new plates and springs will sort that - however
if it feels like a surge like the clutch is being pulled in and out really quickly, that's your gearbox pal and often seen in second and fifth gear. that would be a strip and gearbox repair.

as for the bogging ? check the vacuum pipe isn't collapsing when warm, replace if unsure. sounds more like fuel starvation or fuel blockage / vent blockage

[balen1]

Guessing re doing the gear box would be a pretty big job. Does it require removing the engine out if the frame?

[CRM]

very much so yes. big job that

[Dynamohum]

As above full strip if its gearbox fault but if clutch is adjusted correctly would get the right hand casing off first remove and examine the plates springs etc for wear there's a how to video for the nc30 from a forum member on YouTube . whilst your doing that check the clutch basket for any excessive movement as the large double bearing on the shaft immediately behind can fail also which might be the transmission noise you describe which also plays havoc with the clutch adjustment and the gearbox.

[hunter]

It is possible to replace the gearbox by removing the lower half of the case.
And leaving the heads on.

[balen1]

Ok thanks guys. Maybe I'll just check the clutch places out first and if o replace them. How worn out do the plates need to be before replacing them. And how would you know without comparing them to brand new ones

[VtypeV4]

Visually inspect the the plates - you'll find two types in there: One will be a friction plate with friction material and the other will be blank steel. You may need to look at new springs as mentioned above if this is your issue.

Look at each friction plate and check it still has material front and rear and that it's not distorted. The book will specify a minimum thickness for these. If they fall below the spec, they'll probably need changing..

Check the steel plates for distortion and for any 'blueing' if the surface. If one or a number of these have evidence of this, it shows excessive heat due to clutch slip at high load. Make sure these plates are flat - there'll be a max distortion figure in the book. If they are distorted and worn, it's best to replace them although when I did the clutch on my old Yamaha, they were blue but not distorted so continue in that engine to this very day.

Lastly look at the springs - they will have a minimum height spec in the book and if they fall below it, they're probably toast. Alternatively, you could add another spring or two to the pack at the cost of a heavier clutch action at the lever.

Assuming the clutch is the issue on your bike, it's probably worth changing the friction plates and the springs as they're not hideously expensive nor overly difficult to replace. The other good news to consider is it's likely the steel plates will be fine and good to go again.

Hope that helps.

[balen1]

Thanks everyone and thanks vtypev4 I'll start with the clutch plates then and hope that fixes it.

[Neosophist]

yep always best to check the clutch first.

use a micrometer or vernier gauge to check the plates (both friction and steel) are within the tolerances specified in the service manual and then make sure the clutch cabel is installed and adjusted correctly.