Monday, May 30, 2011

still busy, and lots of work to do......

The RSC90 is costing me a lot of time, in finding the right camshaft, carb settings and ignition timing.
I Have had my second event with a standard camshaft, this didn't do bad, however the carb settings were still of...or were they....
Only fault with the standard cam was a worn out hole for the pin that alligns the advancer. This caused the pin to come out and grind against the housing, causing aluminium flakes to mess up the points.
And that was another racing weekend down the drain.

So we decided to put the 90 on the dyno, although the dyno wasn't 100% functional, we could do unlimited testing.

After 4 runs we really didn't have an idea about the carb settings, but in hindsight something must be wrong with the ignition. (probably the coil)
No really clear runs, but at one point we had a max of roughly 10.6 HP at the rear wheel.
I think not bad for a 100cc, now just to get it running correctly so it will become rideable without constantly feathering the throttle.
(The coil has been sent out for testing.)

But then.... a big crunch and strange mechanical sounds.
some oil on the outside of the engine cover, I suspected the clutch.

Back home we opened up the motor, it wasn't so much the clutch, as the lack of...

Aha, there is the rest of it.

And some debris cought the dipstick, now I have to figure out the level again, probably the least of my worries.

So I have some work to do, the engine is out, we're going to take it appart completely to clean it from bits of clutch. and then install a slightly newer style S90 clutch which has just a bit more material so I hope it will be stronger.
And only 2 days to go before it should be on the track again.

Wednesday, May 18, 2011

been busy

Late update, as I've been busy with too many bikes and things simultaneously, allmost causing my head to explode at some point, from an overload of information.

The RSC90 had its first event....and a lot of bugs showed themselves needing to be sorted out.
The front forks were too stiff, causing the numberplatebracket to bend en hit the front fender.
The rev counter wouldn't go past 5.000RPM because of vibrations.
Carb settings were way off..
or maybe not, as the camshaft is wrong.

The bike felt really!! strong upto about 5.000RPM but after that, there was almost nothing.
So I borrowed some camshafts from Ralph and my dad started measuring.

After that, a load of graphs to compare, and lucky for me, my dad can read these like a book.

including the original S90 camshaft, we now have data on four different profiles, one cam looks nice for racing use, now I hope Ralph let's me use it......
One of my camshafts would be okay for the 122cc engine I plan on building, if it is possible to rotate the camshaft about 10 degrees, creating different timing.

I plan on riding next sunday with a standard S90 camshaft, maybe I can then get the carb figured out. And test the modifications to the front forks, rev-counter stay and so on.

For those of you who like pictures, this is the RSC in action.
click on the picture to see the album of the photographer.

Wednesday, May 4, 2011

first event of this season

last weekend was the first event of this season, I didn't take the RSC90 though, this track was quite long and I want to give the S90 a good chance to have a smooth run in next weekend at Oldenzaal.
In Wolvega I rode the CB72 that I had some experience with last season and one of my dad's BMW's. This was the first time on a 500 BMW for me.
It took a bit of getting used too, especially the speed as I reached over 200km/h on the straight after which I had to brake hard for a 2nd gear corner. But I had fun with it.

picture thanx to Lea, CRT club photographer

No. 64 is me on the CB72, chasing a maico that I passed later on.

Again, picture thanx to Lea.

But I think this picture was taken just 3 corners before the CB72 tried to kill me....
The oil seal in the outgoing gearbox shaft worked itself loose, spraying oil over the right side of the bike, causing me to fall in the only right corner on the track.
Luckaly I could stand up without problems and pick up the bike. Only some bruises to my leg and back.
My ego was okay as this was clearly the bikes fault.

And this is what the CB72 looks like now, taken appart to straighten the front forks, new seal installed on the output shaft, footpeg straightened, but still some more work to be done before I can ride it again next weekend at Oldenzaal.