Thanks for the offer. But rest assured. I'll be bringing everything!! Except the spare bike which is currently still as I left it in the gravel at Rockingham. (A work mate has invited himself along too)
My freshly built Rs250. 3rd time out. 1st and so far only Trackday this year. So I'll be a bit rusty on Tuesday.
Which photo? Me knelt in the gravel or the stink wheel looking resplendent before its trip to the kitty litter? Any joy routing out that map screen grab?
Ha no not the gravel one. The finished article on the previous page. I texted Chris at CJS for the print out but no reply yet.
Yesterday was the first outing on the 924 after its lengthy build and despite a couple of issues it was a semi successful day. The motor felt really strong Compared to the 749 and would happily pick up the front out of the Melbourne loop. I need to improve the throttle pick up as it had a nasty dead band as you got on the throttle at corner entry/apex. Which was a pain in the arse. And I'll have it investigate a potential fuel delivery problem. As it was running increasingly leaner toward the end of the day despite increasing the fueling.
Last night I had a quick hour in the Garage. So did a quick health check on the motor after its first outing. And I'm very happy to report all is well. 225psi compression 8% cylinder leakage (cold) and after a quick peek in with the borescope. All is fine. Phew! Next is to diagnose the lean running. So fuel pressure and injectors are my next patients. (Has anyone else suffered low fuel pressure?) And I'll double check throttle balance. Oh and download the last sessions data.
I thought it was about time I updated this old 924 thread type thingy. Quite a bit has changed since the 924’s debut. I’ve changed job so that ruled out any track time at the first half of 2018. But I’m pleased to say. Since August I have managed 5 trips out on the 924. There is still more mapping correction to do and the ignition can be improved up on. But the bugger goes well enough for me. I’ve bettered my Donington lap times by .9 (1:46.7) but know I can do better. The main thing is it’s now faster off corners and happily passed 600’s on the straights. So job done. I have a few changes to make this winter and must sort a quicker action throttle. The one I’ve been using has a progressive cam and it’s way to slow picking up the throttle at the apex of slower corners. I’ll try to post some footage from Donington over the next couple of evenings. But next up is a trip back to the rollers to tweak the final few bits of fuelling and try a couple of different ignition maps. And maybe a power run ?
I had a trip to the Rollers this morning. Once again a huge thank you to Ian at RPM for allowing me to use his lovely Dynojet set up. It was a bit chilly in there at first. But once the bike and the dyno brake were warmed up it was pretty much perfect conditions. I spent most the time working on high rpm, part throttle mapping and throttle transitions. Which all made sense and responded well to the changes in fueling. I also made a couple of power runs to satisfy my need to know how much it makes and to see how the power and torque curve look and to see where there are holes in power delivery. All looked reasonable. The headline figure if 128.7 @ the rear wheel was good enough for me.
After a few more outings on the 924 and now having the ignition and fuelling pretty good. ( I’m sure I could tweak it more ) But. Since the build I’ve had a couple of clutch issues. The first was my error and easily rectified. And more recently. I’ve noticed a “knock” coming back through the lever when down shifting and inconsistent slip under heavy braking and multiple down shifts. To the point that the rear wheel momentarily locks. I had considered that removing the majority of the flywheel mass was causing the clutch loads to fluctuate. So after a quick strip down for visual check I found the primary spring had cracked. I do have a new spare spring so it’s not a big problem. I has anyone else suffered similar symptoms with light weight flywheel affecting an stm slipper?
