Thought I'd share this as I know many people don't like the thought of spannering themselves, but this is one area of preventative maintenance that most can do easily.
I ought to have taken some photos but as there's a lot on the net anyway, have summarised into simple steps:
Hope this helps.
I ought to have taken some photos but as there's a lot on the net anyway, have summarised into simple steps:
- Bike can be on centre or side stand. First job is to remove the small exhaust shield (small torx bit) which involves just three bolts for removal. All bolts are the same size. Just place carefully out of the way;
- Next, using a 13mm long reach socket, slacken off the main silencer retaining nut on the collar which secures it to the header section. Use a flat bladed screw driver to help shift the collar off the locating slot (obvious notch which collar lines up to) and slide back a little;
- Remove exhaust silencer retaining bolt from the hanger being careful not to lose the spacer at the back;
- Using gentle pressure, rock the silencer side to side and gently extract from the header without the use of too much force. Mine came away relatively easily;
- You now have access to inspect the butterfly valve and check for carbon build up. Next step is the only tricky bit;
- Remove the two small torx bolts retaining the flapper valve black cover and pull cover vertically up and off the top of the valve assembly and put to one side.
- using two open headed 10mm spanners, undo the lock nuts retaining the cable sleeve ends in place. It's a bit fiddly;
- With the nuts slackened and the cable sleeves lifted from their housing, there's sufficient slack to manoeuvre the nipples out from their slots by hand.
- Don't be tempted to use pliers as you'll likely fray the cable.
- I fiddled about for several minutes on the closest (outside) cable and found that by turning the valve towards its closed position, that was easiest and managed to pry the nipple out from the slot. Both cables should be rested on their respective sides so there's no chance of mixing them up;
- Next, inspect for free movement of valve. It should be smooth with no notchiness and should also push down from the top about 1mm and return easily.
- Mine was only lightly carboned up inside so I used a rag to wipe as much as possible away then stuffed a cleaner rag down the sides of the valve to prevent muck and penetrating oil from reaching the cat, as that wouldn't do it much good. Using a small stiff brush, you can clean the inside of the exhaust around the valve back to clean metal. I used a little GT85 to help and removed the excess.
- Leaving the rags in place, next use a stiff brush to clean any crud and carbon build up off the spring, then apply a light coat of GT85 or similar to help final clean up but take care not to use much, I used a small wire brush to clean mine up then a flat bladed screwdriver inserted and twisted in the spring (as per the video doing the rounds on youtube) and cleaned up the turret shaft which on mine wasn't too bad at all. If carbon build up is left to harden on the top part of the shaft, this will eventually contribute to the valve seizing, so 6 to 12 monthly inspection is a good idea. I sprayed the shaft with GT85 and worked it up and down by pressing on the top of the turret, as well as side to side, to remove any slight build up. The rags in the exhaust prevent the penetrating oil from reaching the lower bearing which you don't want happening!
- Next, remove the rags and wipe all excess oil off from the inside, and leave to dry off 10 or twenty minutes, but ensure you replace rags to be safe. Following this, a second wipe down inside for peace of mind.
- Turn attention to the top turret bearing again, using a flat bladed screwdriver to prise the spring coils again and use copaslip grease or spray (both are 1100 degrees heat resistant) and smear the shaft lightly with this, working it side to side and up and down, before removing excess with a small rag and screwdriver or other suitable tool. I used a small plastic rod and bit of rag.
- Do the same to the inside of the shaft at the top of the valve, holding the valve down so you can just smear a little to the bit visible, and work the valve again. It's important now to remove as much from the inside as you can with a rag. Enough will remain on the shaft and bearing.
- At this point, I reconnected the cables (fiddly but no pliers needed) and started the bike, and the valve at ignition on should revert to fully open position. Everything worked as it should, and a quick start up helped blast any remaining crud out of the exhaust so that it didn't reach the cat surface.
- Re-assemble in reverse order and that's job done. I noticed that my cables were bone dry so gave both a good squirt of GT85 into the sleeves and held the sleeves up for a few minutes ensuring it penetrated as far down as possible, before wiping excess from the visible cables
Hope this helps.
