Hondaday today

Today was Hondaday, the yearly gathering of the dutch honda moped club.
In the morning the weather was almost clear, so I thought I'd give the SS50M a ride to completely break in its 70cc engine.
I totally forgot to take pictures, but Ralph will probably put some up on his blog.
Spoke with Ralph for a while about the C110 engine I am restoring for him and the S90 parts he borrowed me. Had a look around the lot, spoke to some other people too and then went home again.
But only after I had the SS50/70 on the dyno. The Honda club had arranged a free dyno for everybody to try their bikes, so I couldn't pass that up.
Graph seen here with some great pictures from Mischa who brought his 1970's polaroid camera.

About 6.5 HP at the rear wheel, not bad for a 70cc with 20mm carb, with a top of 115km/h.
The bike is now totally run in, so it's time to start looking at the 26mm carb that I would like to put on it.

The right tools

Finally my tools are in.
Original Honda crossheaded bolts are different from philips or regular crossheads So I ordered the original Honda workshop tools.

This is worth the money, it really makes working on your old Honda easier.
If you want to order them too, the Honda partnumers are:
07603-0050101 for M5 and smaller bolts.
KL1696 for M6 (engine bolts)
It did take a while because the big size was in backorder for a long time, so be patient.

Lots of racing this weekend

Yesterday we had a race in Nunspeet, I had a lot of trouble getting the RSC running correctly, fiddeling with main jets, but at the end of the day I found the right one. All the symptoms directed me to a bigger jetsize, but smaller was the answer.
I did have a lot of issues with the gearbox though, after the clutch exploded, the gearselector arm was bent.
Pictures can be found thru the Nunspeet bike club website (click "classic race")
What do you know, If you click the 2nd link, the first thing you see is me....

picture thanx to: www.naomischolten.nl
More great photo's can be found on her website.

My dad rode his CB50 with 75cc engine, also having gearbox trouble, first time an original honda 5speed doesn't work the way it should, they are normally pretty indestructible.

My RSC engine was opened up today to fix the gears and it seems to work a little bit better now.
So the RSC is allready on the trailer again for races tomorrow in Varsseveld.
I didn't want to ride the 250 or 500 there, so we got my CB50 out and put it back together again, as some parts were "lent" to other bikes.

I hope tomorrow all goes well, the 90 gearbox should show improvement and the 50 has an experimental camshaft setup.

Cam timing

The trick to timing your cam the way you want to:

Extra holes.
In fact this isn't my camshaft I'm now using, it is Ralph's But we now have it timed for more power at higher revs.
It was probably made for dirt-track or motocross, probably even for ATC's where you would like to have power in low revs, but for roadracing this could be cranked up to about 11.000 RPM.
I don't want to go much over that, just because of reliability and gearbox limitations.

New seat

Bought a new seat for my SS50 off ebay.
The old one made the whole bike look very dark and chunky, with a fully black seat with black piping.
This one has a nice "chrome" edge and its a little thinner then the old one.
It is aftermarket, but you just won't find originals.
And this one fits, unlike the aftermarket stuff sold in the Netherlands or the expensive benly seats that also won't fit with a CD50 tank.

Note the breather, just like his RSC90 big brother.

Anjum

The third event for the RSC90, it was repaired just in time after the clutch thing.
Carb was temporarily replaced with a CB100 part that we knew was working, also the coil was replaced. These were the parts that were doubtfull, so we eliminated them.
A shot in the paddock:

You can see the CB100 carb mounted on an original manifold.
After the training we put in a bigger main jet, it ran pretty well, but the plug was a bit light.
Just one round in the first heat told me that was wrong, I came in, we tried to change the needle position in the hope we could get some progress and I could back on the track for the remainder of the heat, but the clip fell off the needle in the grass.....damn.
But at least we knew now that the bike could run good, and the problem had probably been the coil.
So we put the CR29 back on for the second heat, and it ran pretty well, needle and main jet being allmost right.

Also note the alloy top crown plate from my CR110 replica forks, this was to get less pre-tension on the front forks, a step forward to good handling.
close-up:


A shot from the paddock:


Me in action, must have been the second heat, as you can see the CR29 mounted.

picture thanx to Lea our club photographer.
more pictures of the event can be seen here

the clutch

....or what was left of it, after we fished it all out the engine.

Note the elongated springs and warped clip.

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.

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.

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.