Background: My bike is a 2011 Burgman 400 with 8876 miles on the clock
So i beamed myself up to sunny colchester and met Data early on a sunny Sunday morning.
We started off by taking the left side lower panels off and first came out a very dirty and clogged up cvt filter.
While that came out to be hoovered and washed with a bit of fairy liquid, and left under the sun to dry out, we focused our attention on the belt and transmission casing.
The variator with the filter taken out
It's going to look worse before it gets any better
Casing ready to be taken off.
A few useful tips here from Data:
1- We cut the plastic hooks that held the speedo cable in place and drilled little holes through the material to be zip tied back into place once we were ready to put everything back into place.
2- We labelled all the bolts (there are 10 of them in varying sizes) before taking them off so we wouldn't spend ages trying to find which one fits where.
Trick here is to use a couple of bolts that fits to the holes in the middle of the casing which are long enough to go all the way back to the clutch. To take the casing off, all you do is to slowly turn the bolts into the casing and make them push the casing outwards. However, attention is needed here to lift the casing evenly all around, so we used a bit of help from a rubber mallet and some flat screwdrivers.
Cover off:
Belt looking fine for an almost 9k bike!
Data's homemade clutch bell tool to support the bell and keep it from turning while we took the 24mm bolt off on the middle
Clutch bell off
Quite a bit of dust built up in the bell
So off the bell went to be cleaned off properly, after which we turned our attention on de-glazing the clutch pads
80 grit sandpaper applied gently but firmly in the direction of the turn. Importance here is to keep the surface of the pads as smooth and level as possible, as well as paying attention to their corners.
Transmission oil was next to change. Here's the inlet. We used a turkey baster to fill it.
And here's the outlet to drain it
We then wax oiled, greased, parafinned, hammerited, fs365'ed various things to clean and oil up, before fitting everything back into place. This area of work is a bit misty in my memory, possibly by all the fumes from those chemicals, but also partly because Data seems to have a huge arsenal of chemicals in his garage which would take me a few more times of doing this work to memorize all.
I also changed the spark plug with a Brisk premium one. Quick note here: The plug comes with a metal part screwed in to the side that the cap is supposed to fit, which i didn't notice before, so i had to take the plug out and unscrew the metal part which turned out to be a very tough part to take off.
We then attacked the air filter. The last time the air filter was changed was at 5175 miles, which was only 3700 miles ago, so i wasn't expecting a very bad state to be honest. However, running the bike in London jungle and using blackwall tunnel frequently, coupled with never been cleaned cvt filter (oops) must have taken a cumulative effect to end up in this:
Yep! that is only a 3700 miles old air filter. So ladies and gentlemen, whatever you do, clean your cvt filter every 1800 miles religiously!
Old filter and the fresh new one
Data also spotted some water that got into the airbox strangely. At first we couldn't figure out why this would have happened, but later on as i was down below the bike, i noticed something and it dawned on me!
Top Muppet tip: If you are anything like me and hate the muck and dirt building up on the bottom of the bike in the area above the rear tyre and attack it with a pressure washer, DONT!
I noticed that airbox was sitting right behind that which must have had the water coming in due to high pressure water pushed from the jet.
We also checked the brake pads and engine oil, and tightened the rear suspension two levels up from 3 to 5.
My god! What a difference all this work made!!!
The bike immediately felt so smooth and i can now feel no clutch pickup as it smoothly engages from starting up. Engine is much more responsive now and feels easier to rev. Mid range acceleration feels less restricted too, especially helps overtaking other vehicles.
Coming to Data's starship headquarters in the morning, i left home with computer having averaged 14.5 miles/L commuting into london previous week and after a steady 75mph over 65 or so miles i noticed it had dropped to 14.2 miles/L.
So i was expecting things would have improved on the way back...
Going back home, Data kindly led me to a nearby petrol station where i filled up and reset the computer, then went back home on a steady 75 mph...
And instantly i knew there was a problem, i was expecting things to improve but i wasn't expecting miracles! The reading slowly started going up from 14...15...16... all the way on to 16.4 miles/L
It was shocking to see such a difference. Not only the bike was more responsive and less restricted, it became much more economical too.
The change on the suspension also transformed it's handling. My biggest gripe with the burgman 400 coming from a tmax was its handling. It used to bounce up and down and act wallowy on any uneven surface while i was leaning and turning, which led me to have a wider angle of turn than i used to have on the tmax, and turn slower too. Only 2 notches of stiffening has made the burgman's rear so stable now, it feels as if i'm going on rails! On the first roundabout i tried, i was expecting to have to slow down but the bike already was in the turn and begging me to speed up, as if saying "Right, turn sorted, what now, give me some more angle damnit!"
I'll continue to observe the handling and engine over the coming weeks and keep collecting my fuel economy information on fuelly, but i can say it has been a very useful and enjoyable day for me.
Again, many thanks to Mr and Mrs Data for their time and kindness! I am enjoying the Burgman much more now!
(hell of a mix!)