The Burgman clutch shudder or judder (sometimes with the accompanying moan) is mostly not a big issue. If you have it, it's very easy to cure, even for mechanically challenged people so long as you do some research first and take your time. Most don't experience it. But if you do a lot of start stop in heavy traffic everyday, or have been very gentle with the throttle from new, causing prolonged clutch slip as you move off, then you will probably get some judder at some point due to the heat that type of driving generates and the glazing of the clutch pads and dust caused. New riders to the Burgman 400 who are not sure how much throttle to give their new baby when moving off (moving off too gently) can often experience it before 4000 miles. But clutch shudder/judder on the Burgman 400 is not really a fault in my view. It's something all dry clutches of this type can experience if not maintained properly. Preventative maintenance is the key. But judder is more noticeable on the Burgman than some smaller bikes. I even experienced it the other day on a Silverwing 600 which uses the same type of clutch but the owner hadn't even noticed...probably because it's a twin engine. The Burgman single makes it a bit more noticeable.
So, what do you do to cure it. It's actually quite easy. The shudder/judder and noise is caused by dust in the clutch bell and glazed clutch shoes. Glazed clutch shoes can be a blue but mostly they are not. They are just very shiny due to the resin in the clutch lining bubbling to the surface due to heat caused by excessive friction. That's all. It's no good just cleaning out the bell, or just de-glazing without a clean of the bell. Both need doing and it'll be fixed and should run for ages without a problem.
Here is what my glazed clutch pad looked like: the glazing doesn't need to be that heavy to cause a problem. If you can see on the pic, the surface is very shiny with resin which heats up again as the clutch is used and sticks and jumps inside the clutch bell as it mixes with the clutch dust.
View attachment 12770
A couple of points. Make up your own clutch holding tool. There are videos by Micbergsma on here to show you what it looks like and the dimensions. When you clean out the clutch drum or bell use brake cleaner or thinners to wipe it clean. This helps to dissolve the thin resin layer that has built up inside the drum which you cannot see. Next, use a heavy grade sandpaper or emery cloth. About 80 grade
is best. DON'T use a higher number than 100 grit.
You are aiming to expose the fibres of the clutch pad by removing ALL
the surface resin to bring the clutch pad back to new. You won't do that easily or effectively with 200 or 240 grade and the judder will come back very soon. Don't worry about wearing out the clutch pad either. They are very thick and last ages. You don't have to take that much off to remove the resin and expose the fibres. Next, chamfer the leading edge using the 80 grit paper.
Here is what my clutch pads looked like after de-glazing:
View attachment 12762
You don't need me to tell you how to dismantle the bike to do the clutch job. Micbergsma, the excellent guy on here who has given up so much of his time to help us all, has many videos to tell you how to get to all the bits.
Almost ready for assembly:
View attachment 12778
Just one point. The torque figure for the Burgman 400 clutch bell is
different to the Variator. The bell needs torquing with dry threads to 85nm.
Then just add some grease (very sparingly) to the clutch end shaft bearing surfaces to make sure the cover assembly comes off easily next time.
I've fixed many of them and it takes about an hour and a half if you haven't done it before or 40mins if you know what to do and have done it before. But the best way to deal with it is regular clutch maintenance every 7500 miles. Since you will have the transmission cover off to change the rear transmission oil, it's just one more nut to undo and clean out and de-glaze the clutch whether it needs it or not. Or you may only need to do the clutch clean every 15,000 miles. It adds about 15mins to the total transmission oil change job by adding in the clutch clean and de-glaze. That's all.
Do watch Mic's videos before you do it. It makes it easy. Good luck!