Jetting - 2012 Beta RR50 Factory

[Yamezz]

Hello from Australia,

My apologies for writing in English, but this seems to be the best forum to find the answers I'm looking for.

I have a 2012 Beta RR50 Factory and I am looking for jetting recommendations for the Dell'Orto PHBN 16 HS carby. I have removed the exhaust restrictor and the air box lid and the bike currently has a 110 main jet from the spares kit. The bike originally had a 76 main jet when delivered.

Where I ride ranges from about 15 degrees Celsius to 35 degrees Celsius, from sea level to 200 metres elevation. Does anyone have any recommendations for suitable jets to try?

Thanks.

 

[1979-KTM-MSS-50]

Hi Yamezz,
Whats the problem with your bike?
Why do you want to have a other jet in your Dello?

In many countries the bikes are different in new condition. In Germany this bikes are only allowed with a maximum speed of 45 km/h. In Spain for example its allowed with 80 km/h i think. The setting is different so we have to know from where you are.

 

[Yamezz]

There's no problem as such, apart from a very narrow powerband, but I'd like to have the motor producing as much power as possible (without going too lean).

50cc bikes like the RR50 are not sold here in Australia, so mine was a special import from the Italian factory. I'm not sure which market my particular bike was originally built for.

I only ride this bike on my property, so there's no rules about maximum speed etc.

Thanks.

 

[1979-KTM-MSS-50]

How much is the maximum speed?

 

[Yamezz]

About 70km/h on the flat. On a down hill slope I've had it up to 79km/h

 

[1979-KTM-MSS-50]

Thats quite okay. This bike is the open version i think. If you want it faster, you have to buy some spare parts like a complete sport exhaust. Your 110 jet might be enough for the grand open setup.
Maybe a sport ignition ( CDI ) will help too. If you want much more try a bigger carburettor.
If you only drive on private property this setup is okay.

Please remember: You need good brakes as well. A fast bike is nothing without excellent brakes.

 

[SuMo_freak]

It seems that you have the "normal-standard-open" version of the bike.

Your Bike and Main Jet seems to be alright, 110 Main Jet is approximately right.
At normal conditions the bike should be running about 75km/h without any problems, that means you should have a good acceleration in the first three gears.

As 1979-KTM-MSS-50 already said, for more power (top speed) you should try a bigger carburettor, another exhaust-system or/and another transmission

 

[Yamezz]

I guess to be more specific, I would like a broader power band. What parts would you use to achieve that?

The Beta website previously listed a 70cc kit, but I can't seem to find it now.

 

[SuMo_freak]

I am not sure that a 70cc-Kit is the bst solution for your problem....

The small Powerband is a typical thing of 50cc-Motorcycles, they have not enough power to have a wide powerband. All 2-Stroke Motorcycles (As your Beta is it) have a good acceleration from around 7,500 rpm up to 10-12k...
under around 7500 the acceleration is low...
as already said, that's a typical thing of 50cc-Motorcycles, I don't exactly know how to find a solution for this problem. Maybe a bigger carburettor can help..