engine upgrade

[givusago]

Hello,

New member here. I am quite new to the world of bikes but I have a question.. I have looked through previous posts and the 150cc upgrade kit. (I have an mz rt 125cc) Just seeing if any one has upgraded the engine at all? I am using this bike to learn the roads etc before I go on to do my Direct access. Once I pass though I will want something a little meatier. maybe its easier to just buy a bigger bike but I like this little one and wanted to know if it could be done at all?

Many thanks

Mark

[DAVID THOMPSON]

the rt125 is best used stock.. supplies of hopup parts never were easy to find and even less now
over bore kits above 140cc do not work very good as the piston just gets too big
i think overbore is a waste and not worth the money

if its an rt125 the best mod is to put a 52 tooth sx sprocket on it this makes it have a top speed
of about 69/68 mph and a lot quicker on the low end and climbing hills
and use a standard chain the o ring chains just load it down
details here in this link

viewtopic.php?f=4&t=49&p=196&hilit=sprocket#p196

i have 21,000 miles on a 2002 and love it
just remember its just a BIG MOPED and enjoy ..

most mods make it run bad and get bad gas mileage
this bike is very light and speeds over 65 mph are scary
WANT TO GO FASTER get a 750cc bike
DAVE

[therealche]

And I think you may be confusing the TS125 ( 2-stroke) which is easily increased to 150cc, and the more modern RT125 (4-stroke)

[givusago]

thank you for the answers..

I do like the rt 125cc, lovely bike. Easiest thing to do is just buy a bigger bike if I wanted more power but wanted to see if anyone had stuck a 250cc(for example) into the frame.

Thanks again

[therealche]

Anything is possible but it would be a lot of work, for unknown results, and you end up with a bike no one wants to buy off you when you want to move up to a bigger bike. Better off selling it and introducing someone else to the wonderful world of MZs

[givusago]

True. I will probably keep it though.On a side note is 15w40 the best oil for the engine?

Many thanks