The weird business of the bike cutting out seems to have resolved itself, it was still there when I fired it up this morning but after leaving it to warm up whilst I got my leathers onit had sorted itself. I’m intrigued now as to what it was but probably won’t find out as I won’t have to take it in to the shop to be checked out. The down side it that I’ve now no excuse not to do the oil change myself, or change the chain, which still has the tight spot.
After sticking with BP fuels to check the mileage I was getting on the new car, and deciding that Ultimate was not worth the premium, I put through a couple of tanks of Sainsbury’s City Diesel and it gave almost the same MPG as Ultimate but without the premium, so I will be filling up at Sainsbury’s for the foreseeable future. I also put a K & N air filter in to replace the paper one. I’ve heard many claims for these over the years and it would seem that at least one of them is correct. These things use an oiled cotton matrix to filter the air entering the inlet manifold and offer less restriction to the airflow. My first thought on this setup is that it would offer improved throttle response but not much else but this has not been the case. There's maybe a little improvement but if so it’s not terribly noticeable, but the improved fuel economy is. Still using City Diesel the consumption has improved from 55.2 MPG to around 60 MPG which is about 8.5% improvement, which means on current usage the filter, which cost £42, will pay for itself within 4-5 months, which would be worth it even if it got changed at each 12000 mile service, but it doesn’t need to be changed, it has a lifetime guarantee and a little sticker to go on the airbox to tell the grease monkeys not to touch it. It does need cleaning and re-oiling, but only after 50000 miles and the kit for this is £15. It was a doddle to fit, take out the paper filter and the K & N slips straight in without any modification. The biggest problem I had was the first supplier I rang tried to sell me the induction kit?! There are tales that the filtration they give is not adequate and result in increased engine wear but I’ve not seen anything conclusive to support this but with the savings on fuel and replacement filters I can well afford to clean and re-oil it at 25000 miles.
