Time to do a bit more...

After Thruxton we had a bit of a break before the next race so I decided to see what improvements I could make.

The brakes were seizing on, so I bought new caliper seals. If this doesn't solve it then I'll have to try new pads, which is a shame because I've been getting on really well with the EBC HH's. Thing is, I'm removing the charging system so I'll have to bump start it and binding brakes will be even more of a problem.

I've spoken to a fair few people regarding what to do and I've come to the conclusion that I may as well just try it. As long as I keep the parts and don't break anything then I can at least return it to the state its in now (57bhp). First up was removing the exup valve and associated bits. To do this I emptied the water from the cooling system, removed the radiator and then removed the header pipes. To get the exup out you just undo the bolts and then lever it out with a screw-driver (with a few encouraging taps with a hammer). To block the hole I just used a nut, bolt and washer, treated with threadlock and done up really tight. I might make up a blanking plate out of alloy to save weight but at the time I wanted to retain the seal. Maybe a later mod. The exup servo is attached to the frame with two bolts and the wiring is just a block connector. I have a kit CDI which I've been told will be fine without the exup, not sure if you have a standard CDI.

Next up was removing the flywheel. Why? Well, cause a couple of people told me too. It's supposed to help the motor spin up quicker and I'm after every bit of help I can get. The flywheel also affects the ignition as there are four points on it and as they pass a 'pick-up' that sends a signal to spark a plug. So, you can remove the stator (the generator/copper wire/magnets thing) to save weight but if you want to remove the flywheel you need to replace it with something. BDK do a ignition advancer and rotor for around 145 so I figured I'd give that a go (he says casually without mentioning that he's on bread and water for the next month to pay for it). Alledgedly 3-5 bhp can be gained by advancing the ignition a few degrees. We shall see.

The first picture below shows what you get for your money and the second is roughly how much it all weighs (click on the pictures to see bigger ones). To fit it, remove the engine cover. The stator is attached to this so follow the wires and disconnect the two block connectors. Now you have tricky job number 1. For well prepared people you will have (or have a mate who has) a rattle gun. If thats the case, undo the nut. If not, put a ring spanner on the nut, hold the spanner in place and with a slight grip on the flywheel, crack it with a hammer. And I mean really twat it. The idea is that the sheer force of the hammer hitting it will shock it loose. Repeat the 'twat it' method about 40 times until it works, or visit a dealer.

Problem 2, getting the flywheel off. On a scale of 1 to 10, getting the bolt out was a 6. Getting the flywheel off is in a range, ranging from using the correct tool where I guess it would be easy, to 9 doing it the way I did it. I used an old original bar end weight. I won't bore you with the 1.5 hours of failed attempts I'll just get to the successful way. I filed two flats onto the bar end, then I attached a spanner (by whacking it on with a hammer). I sprayed a graphite spray for loosening bolts at the flywheel (many times as part of the previous hour and a half) and then I gave the spanner an almighty twat with the hammer. And popping the flywheel off was as easy as that. Make sure you have the slot facing upwards when you pull the flywheel off as theres a little woodruff key in there that you don't want to lose.

Next up I removed the stator from the engine case. I then used a Stanley knife to carfully slit the black cover that all the wires go through so I could seperate the pick up wires. I sliced the rubber mount too. I then attached the pick-up plate (the silver bit) and then attached the pick-up to it (the black bit). To the right of the pick up you'll see lines. These are timing lines and to the left of the phillips screw you'll see a point, which is the timing marker. The lines allow for up to 8 degrees of advance. As advised by BDK, its set at 4 degrees for now. The next picture shows how much weight has been removed, around 2Kgs in total (+ all the exup bits I didn't weigh). Push the new rotor on making sure to line up the woodruff key to the slot. Then torque it up (58lb ft), which is easy with a big spanner to hold the rotor in place. I put the black cover back on the pick up wires, wrapping tape around it to hold it together and I refitted the rubber mount. I put it all back together and it started first time.

I stripped the brakes and fitted the seals, which was pretty straightforward this time 'round (take a look at the winter rebuild pages for details of how to do this). I've booked the bike in to see James Holland at JHS Racing so I can get the carbs set up properly. As soon as I have a new dyno print I'll scan it in and we'll see whether any of this has made a difference.

UPDATE - Picked the bike up from JHS Racing yesterday. James spent the best part of a day working on it and the dyno charts below. The result is an extra 5bhp from 11,500 through to just over 13,000, right where I want it. Also, instead of it being overly rich it is now very slightly lean in this range, richening up as it goes above 13,500. Hopefully this will mean a crisper throttle response in this vital area and there's also a couple more bhp all the way from 7,000. James also adjusted the throttle cables as he reckoned that I couldn't have been opening it fully before. He also pointed out that I'd missed a bit of the loom with the tape last time - there's no pleasing some people is there? Anyway, on paper it all looks good so read the Keevil report in a few weeks time to see what I think of the mods. Oh, and big thanks to James for the effort he put in, thoroughly recommended.


what you get