Author Topic: BURGMAN 400 Scooter -- CVT Inspection Experience (made me nervous)  (Read 1453 times)


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Not knowing what I was doing (let's say no experience on the Burgman 400 CVT), I watched You Tube Videos (there are a bunch).

Then wrote me a procedure (steps) and jumped in like I knew "How To Swim". Thought at one time I had gone under (drowned).  ::)

All went pretty good (even managed a half decent re repair (repair to PO's repair) of the cracked pals tic on the lower left leg Cover (they call it that, but it runs under the floorboard and the length of the floorboard - nothing to do with the leg cover). I had to remove it to get to the CVT Cover bolts. So, decided to scrape off his hard glue (JB WELD maybe) repair and use Plumbers Goop (my new fix everything adhesive glue). Had a heck of a time holding things together to let the glue set. Second attempt, I found a little clamp I had in a box that did the job (pretty good).

That was off the subject -- so here is the CVT story. (pictures might make sense of it - if interested enough to give a Rat's A__  ???

Some pictures just show the make up of a CVT. Primary Pulley in front (open when stopped so belt drops down for a low radius and the secondary pulley tracts the belt so it is closed and belt is at outside largest diameter -- BOTH of THOSE THINGS GIVE MAX TORQUE for takeoff).  8)

Then as engine speeds up and Primary Pulley RPM increases  -- weights on the back of the inside pulley swing out to the edge (centrifugal force) and cause the pulley to close the gap. That forces the he belt up for a larger radius and the secondary pulley tracks to a smaller radius. BOTH OF THOSE THINGS GIVE MORE SPEED AND LESS TORQUE.  8) also.

Need something to allow pulleys to turn and not drive the wheel (like when stropped at a red Light).  ::)  The clutch is on the secondary pulley - the bell housing (thing with holes in it) is what drives the rear wheel (which is nice). The housing does not get torque until the secondary pulley speeds up (that starts at about 2000 rpm engine sped and is fully engaged at 4000 rpm engine speed). It is engaged by shoes (5 on the 2008 and later Burgman 400s) when centrifugal force (that word again) forces the shoes out against the bell housing. SO - A VERY SIMPLE TRANSMISSION. Belt wear is an issue (some say 15K miles and some say as much as 25K or 30K Miles). Then the clutch shoes wear also (some say 30K miles and some say more).

Note the picture (taken with mirror) of a clutch shoe. Not much wear at 6000 miles and the belt also looks good at 6000 miles. I measured it at 1.04 to 1.08 inches width. Eric said since the belt is filling he secondary pulley at stop - it is in good shape.

Now the problems -- one is minor. The darn ties for the wire harness or inserted in the cover ( a hole) and no way to release them except to get behind the cover and push the pin out. Dumb and likely destroy them anyway.  I broke one out of the hole trying to figure out how to release them. I then cut the other two and later punched holes in those straps and used 'lacing cord' to tie the harness. The one I broke, I used a wall type of hanger (Plastic) and inserted it ion the hoe (tight fit) and then a screw to spread it and to tie the wire harness to the screw with 'lacing cord'.

THE BIG PROBLEM was getting the cover off the case. I shook, jiggled, pulled as hard as I could and gained maybe 1/32 inch gap. Then used a pairing knife edge and hammered it in the crack, then added anything I could find to stick in the gap. Maybe a little over 1/32 overall. Called Eric to see what he thought. He came over and away we went.

Prying, shaking, pulling, and finally got it off the guide pins 1/4 or 3/8 inch gap.

Still, the cover would not come off.  It seemed to be held at the center of the Secondary pulley and clutch. I remembered that the shaft of the Clutch fits into a bearing retained in the cover. Found out later that it is a common problem to be hard to get the shaft out of the bearing inner race. There are a couple ways to do it ( a puller, and a jury rig using tow bolts), but we did not know that and kept pulling, jerking, shaking, prying. Surprised we did not damage something. GOT 'ER DONE.

Cleaned the shaft and inner bearing. applied a little grease (should have use anti size). Too late now.

We had damaged the wire gasket between the cover and case. Tried to straighten it, but could not get a good fit to install it. So, I used Painter Tape (blue stuff) to make a gasket. No liquids involved with the CVT -- just need to keep metal to metal (cover to case) away (my opinion) and road dust and dirt from entering there.
Ride Country Roads - a lot. :-)


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Re: BURGMAN 400 Scooter -- CVT Inspection Experience (made me nervous)
« Reply #1 on: April 15, 2014, 08:36:45 pm »
10250 Mile CVT Cover Removal primarily to change the Final Drive Oil (you have to take the cover off to get to the fill /level hole on the final drive -- Lousy Design).

While I had it a part, I did a CVT Filter Wash, Belt Measurement and visual inspection, a limited Clutch Pad inspection using mirror, Case Bearing check by rotating it, and Final Drive Oil Change).

By the way -- I did not take plastic all the way off, just enough to get it out of the way.

CVT Case Cover came off a lot easier this time (I was able to just shake it loose using the air outlet and air inlet as hand hold. I plan to lubricate the shaft that goes into the case bearing again (Wish I had some Anti Seize on hand).

Note: Painter Tape Gasket (blue) installed at 5200 miles inspection is OK with some dirty look on front end (left end in picture). Maybe a bit of leak there, or sling off form the belt getting into the groove. Rest of the inside of the CVT was clean with some belt wear off accumulated around the case bearing where I had lubricated somewhat the last time I had it apart.  I plan to replace only the portion that needs it (maybe double thickness on the front end). 

Belt looks good to me (Measured 26.05MM - reading from 25.99 to 26.10). Accuracy is questionable as very hard to get micrometer in there (only fits two places and hard to make sure you have it straight). I think 26.05MM +/- 05MM.

Clutch Pads appear in Good shape as far as you can see with a mirror. I took one picture with just a trouble light on the area and next with a flash from the Smartphone Camera.

Final Drive oil was very dirty.  I ran some fresh oil thru to wash it out before refilling. It only holds 80ML

CVT FILTER - first wash (10240) since new. I did brush it out and blow it off some when I took the CVT case off for a look at 5200 miles. I washed it this time with warm water and hand soap (it was pretty dirty water when I finished). I then rinsed it thoroughly under a good faucet flow in reverse of air flow direction (use hands and fingers to support the foam so it does not tear) Let it dry thoroughly before installing.   
Ride Country Roads - a lot. :-)

Offline Curtie223

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« Reply #2 on: April 18, 2014, 07:24:55 am »
Good job Paul. :n21

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