MZ/MuZ Riders

Chaps my sport would like some more power.

On open road rides I find the power really lacks beyond 100km and long steep hills can be a chore, I really didn't expect that from a single 660cc!

I know the bike could probably do with a bit of a tune up to get it running a little better but if im honest its a bit smoky and does go through oil so I think a top end rebuild is probably due (bike has done 70,000km and I presume hasn't had a rebuild).

Important notes
I would like to do this myself, I am fairly mechanically minded but will need some help along the way
It is a street bike and not raced but I don't mind if it runs lumpy and rough/hard to start etc like a race bike
The rest of the bike is standard but im not against changing exhaust/intake etc if that's worth doing
I like torque and dont really find myself revving it out much, I would like to open throttle at 100km in 5th and have power on tap to pass without dropping down a gear
I would like enough torque to lift the front wheel and give me the odd fright and keep me on my toes
My wife doesn't know so I need to keep it fairly cheap!

What are my options?
686 kit? are the Ebay ones ok? what compression ratio should I be getting?
Other options?
Peoples experience?

Thanks!

regear it i find the germans are bad about gearing a bike to tall
had a set of 3,36 r50/5 gears ia r90s for a while top end speed stunk
but from 40 to 75 mph nothing could keep up
my rt125 is regeared 52 tooth rear in place of stock 49

tops out at 69mph but works to that speed much better
my speed limits here are 55 or less on all but 2 roads
and i seldom use them

Dave

Rebuild top end and check the valve seats. I wouldn't be surprised if you need a valve job, piston and bore to 101mm. No need to go straight to 102mm, which would be the 686 kit as it would just be extra cost at the machine shop. You may not even need to go to 101 if the cylinder is in good shape as you can get 100.5mm pistons. Put a proper air filter on it and remove the snorkel on the airbox, check the header welds to see if you can open them up a few millimeters with a die grinder, then re-jet the bike. The last step may get expensive unless you have a connection to a good mechanic and/or dyno with exhaust gas analyzer, but you will benefit greatly if the other work is done right. A Megacycle X2 cam rebuild would be icing on the cake.

Hi Toledo, in all fairness my 10'000 mile sport will do 100mph (160kms) in standard form on original gearing with good quality fuel if that's a benchmark to work from? Eric

Toledo, what did you do on your engine, and how did it work out?

Hi toledo.
Have you done a compression test?
It`s got to be getting `tired` at that sort of mileage i suspect and combined with standard (overgeared) gearing is not a good combination.
I run a Mastiff with more`open` inlet and exhaust systems and 15:43 (standard) gearing. It now feels slightly undergeared but is bloody quick!
Currently 70mph is 4500rpm (Corrected from previous post)

Zombie alert - the OP hasn't been in for 4 years...