G'day from Queensland Australia

Bernie

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Jun 22, 2009
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Australia
Hello all,

A few weeks ago I helped a friend clean out a snake infested shed deep in the Aussie bush where he had stored bit's and pieces for years. One 'piece' was a bicycle with a German made Sachs 30cc two stroke motor driving the rear wheel. It appears years earlier his missus lost her drivers licence for serious DUI (six times over the legal limit) so John bought this machine for the silly chook.

Poor thing was forever going over the handlebars (due to drink) and soon she was over the thing. It remained in the shed ever since. She and John have long since divorced so I made John a modest offer for it and now have a little bike which gets along at about 14 to 16 Mph and uses little fuel.

I also bought John's 1980 Model Kawasaki 750Z which has been standing in the same shed unused for around 12Years, but as yet have not had time to get this serious looking thing running. Frankly, it scares me a little.

These little Sachs contraptions are governed to 200 Watts in Australia but I have learned ex-factory they come with 500Watts (1/2 a kilowatt) or about 0.7 of a HP. I have also learned there are countless THOUSANDS of these machines in use in Europe, in particular Holland and Germany.

I have also discovered those clever Dutchmen have found the CDI units in these machines have a rev limiter built in, reducing RPM to 3,800 and the simplest way of re-gaining the missing 300 Watts is drilling a 6MM hole into a particular spot on the CDI and they will run over 6,000 RPM. This simple modification has increased the speed of my machine from about 20Kph to about 33Kph.

Meddling bureaucrats (and elsewhere) in the EU are responsible for turning highly developed little engines into asthmatic contraptions which would hardly pull the skin off a rice pudding. But the Dutch have found a way around it. I'm really delighted to have re-joined the World of motorbikes after so many years. I intend to build a few more little mopeds and get the mongrel Kawasaki going. I had two Matchless 500CC singles back in the 1960's when I was a 16 year old.
 
G'day and wellcome to the Forum,yes my ex-country men are pretty resourceful,Sachs has a good reputation in Europe.Watch out !! with the Kaw. 750 ,it's a beast,I settled for 550cc version,that one was bad enough,would do well over 160 km but handled quite well,750 would really be a handful,mismatch between performance & roadmanners.These old 70's 2 strokes are still hard to beat,I still have a Yamaha 400.Less thirsty but still lots of fun to ride.Freq. the roller&needle bearings get rusted while sitting for years in storage,but Queensland is prob. pretty dry,so you might be in luck.I liked Queensland a lot,visited Brisbane,Noosa&Fraser Island
 
G'day Bernie & welcome to MBc.......nice intro.
"drilling a 6MM hole into a particular spot on the CDI".....Sachs huh,please tell more(with pics if possible)
Hope it also works with the Rotary brand,instead of constructing a new CDI.
 
.Watch out !! with the Kaw. 750 ,it's a beast,I settled for 550cc version,that one was bad enough,would do well over 160 km but handled quite well,750 would really be a handful,mismatch between performance & roadmanners.I liked Queensland a lot,visited Brisbane, Noosa&Fraser Island

Thank you my friend. Don't worry, that Red Kawasaki really scares me bigtime and it may be some time before I get round to getting it going for that reason. There is also the question (here) of a license to ride the mongrel. In Queensland there have been so many fatalities of Bikers that the PTB ruled you need to have held a bike licence restricted to 250CC for a full year before you are let loose on a superbike.

I had a look at the 1980 model 'Kwaka' 750Z specifications and it evidently had 56 kilowatts! That's about 80 Horsepower so this qualifies at least as a 1980's superbike. It is a four cylinder OHC aircooled machine and it has just 38,000 klm's on the Odometer. Although to be honest I haven't yet really had a close look at it as it is still in my mate John's snake infested shed in the bush. I also have been preoccupied with the neat little Sachs powered Moped. as I said, I had two 500 CC Matchless singles as a Kid way back when and never once did I hurt myself on either bike. I just hope I still have the same level of common sense at my age today, as I did as a teenager back in the 60's.

Glad you liked Queensland.
 
G'day Bernie & welcome to MBc.......nice intro.
"drilling a 6MM hole into a particular spot on the CDI".....Sachs huh,please tell more(with pics if possible)
Hope it also works with the Rotary brand,instead of constructing a new CDI.

I attach a picture of the CDI Modification. Be aware that my (1992) SACHS is a model 301A with a BLUE CDI unit. Evidently the blue CDI is the most common but there are RED and BLACK CDI units.

For heavens sake do not go drilling holes into your unit until you have comprehensively researched the subject! I went so far as to JOIN the Dutch Saxonette forum (I understand German but struggle with Dutch) and having babelfish translate the posts until I understood what they were on about.

What I found was, with few exceptions, all the guys, who after reading the quite amazing increase in performance obtained by drilling the CDI came back enthusiastically relating their experiences. I also learned there was a Dutch guy, name Jan jhcvaal@kabelfoon.nl who is the World expert on these and will supply a modified CDI for 45 Euros plus postage.

From what I can tell the restriction simply limits the motors RPM. Take it away with the drill and the little motor behaves as its designers intended. There is a whole WORLD out there of which I was unaware! All these guys who love mucking about with tiny motorbike engines, I love it! According to Jan a few other mods and you really get a tune out of the Sachs. He reckons the best speed so far obtained is 58Kph! I hasten to add that mine runs to about 30 Kph or maybe a little more. I don't have a speedo and the roads around here are typically Australian rough bitumen. At anything over about 23 or so (a guess) there is considerable vibration through the handlebar of the Bike which is tiresome. I am thus content to tootle along at the lower speed and watch the scenery pass and since the modification I seldom have to pedal unless the hill is quite steep.

I cannot say what effect (if any) it may have on the Rotary made Motor. I understand these are exact ASIAN built copies of the Sachs 301A motor. If so they should behave similarly. Beyond saying beware, that's all I can do.

All the best to you.
 

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hey Bernie,
amazing story. Its a story all too common, lost license for DUI, find alternate,
have trouble with alternate...
six times the limit, she must have been a heavy drinker
to achieve that.

And sounds like she kept at it too. :75:
Never can keep a determined person away from their fav past times eh ?:devilish:

Appparently the dutch are well ahead on accepting many of lifes,
alternate pursuits. MB's are one of them.

I wonder if that Saschs 30cc with the limiter would be classed as legal here ?

i digress, welcome. :cool:

PS fill in your location...helps work out your stories.
 
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hey Bernie, amazing story. Its a story all too common, lost license for DUI, find alternate, have trouble with alternate...six times the limit, she must have been a heavy drinker to achieve that.

You're not wrong mate. Poor Girl, this was the second time she was sprung, the first she had three little Kids in her Mercedes and was 0.290. Last time she drove a nice little BMW out of their country driveway hitting the concrete post tearing off the LH Mirror on the way. Not more than 200 Metres down the frog & toad she hits, or is hit (head on) by a Toyota land Cruiser. She now does a runner from the scene and is found by the police, unconscious from drink in the scrub a few hours later. Worst alcoholic I have ever seen and I've been around heavy drinkers all my life. I am not exactly averse to a drop myself.

I know the UN-modified 30 cc Sachs is legally treated in Australia as a bicycle because it is restricted to 200 Watts. But I think mine with the hole in the CDI is probably back close to the original Manufacturers specification of 500 Watts. That makes it illegal here I reckon, therefore I am a criminal which is why I'm not real keen on mentioning my exact location in the vastness of the sunshine state.

On the Dutch I agree with you. They have always been an industrious, broad minded people, there's certainly a lot of bikes there. I read somewhere there are 680,000 of the 30CC powered Sachs motors pushing bikes around in Holland and Germany. If so, the guys at Sachs must have done something very right at some point eh?
 
You have a later bike 4 stroke 750, probably better behaved and more likely to have survived intact,the one I tangled with was the early 70's 3 cyl 2 stroke with even more power than your 4stroke,really scary doing wheelies at 60 mph,guzzled gas too.The 550 had the same frame and was a great bike.the Law seems to dislike 2 wheeled vehicles in A.I must say Aussies do drive like maniacs on not (mostly) not the greatests roads either.Good luck with your little 30cc Sachs
 
.I must say Aussies do drive like maniacs on not (mostly) not the greatests roads either. Good luck with your little 30cc Sachs

The more I think about that bight Red 1980 Kawasaki 750Z monstrosity the more I'm wondering what the devil I was thinking when I bought it.

A few years ago I was doing some slashing on paddocks at my son-in-laws place with a Tractor towing a big mower. I noticed the remnants of a trail bike perched on the western side of a shed almost completely overgrown with grass and weeds. After finishing about 5 acres I mentioned this to him. He'd completely forgotten about the bike. A few years earlier one of his mates left it there and went to Europe.

We dragged it around to the workshop and began to see what it would take to get it going. Tyres were flat and filled with rain water, it needed fuel and a general clean up and after an hour or so we got it running, a very loud, sharp, rasping two stroke, which suddenly made me quite nervous..

I asked him what make of bike it was, as it had (from memory) no visible ID. It was a Yamaha YZ 250 he said, evidently in its day a very hot two stroke competition bike fitted with the barest of minimum by way of lights and indicators to make it legal to street register in OZ.

It was many years since I had been on a bike of any kind, but I'd spent several hours earlier that day on the Tractor slashing grass on a rectangular 5 acre paddock. Every inch of it was fresh in my mind. I knew where there were bumps, rocks or stumps, so I felt less uncomfortable in giving the bike a bit of a squirt on it.

Let me say it gave me a severe fright! I belong to a generation which regarded 250's as Girlie machines, even the old 350's were for lightweights. This thing almost tossed me off in 1st gear and in 2cnd with its very peaky power delivery. I think I also got it to begin to lift the front wheel, even in 3rd before I came to my senses. Soon after the bike was no longer there, gone to one of their mates on a place way out west in the sticks where they use these things to round up stray cattle.

I hope he hasn't killed himself on the thing.

I can certainly see the attractions of the Mopeds. I might fit a sidecar to the Kawasaki to slow me down.
 
That YZ 250 was just a Girlie machine compared to the Kaw 750 2 stroke,I think the thing still holds a few world speed records after all that time.Going straight ahead was it's specialty.
 
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