Two Stroke Racelab

Sakis Vasilopoulos won the first award at Dania Vintage Motorcycle Show with the help of his Yamaha Tz350 Kenny Roberts bike. Enjoy the pics...

Info & pics available at : 2stroke.gr bikerspirit.net

Ετοιμάστε τις διχρονίλες και ελάτε να κόψουμε τη πίτα μας για το καλό του νέου έτους. Μπόλικες εκπλήξεις - δώρα, διχρονοκουβέντα και μπυροποσία θα μας περιμένουν στο Pit Stop, τη Κυριακή 26 Ιανουαρίου. Περισσότερες λεπτομέρειες στο παρακάτω  ...θέμα.

Sakis and his Yamaha TZ350, last weekend at Homestead Miami.

Frits Overmars is a well known tuner and very knowledgeable on Aprilia 2T racing bikes. The below schematic with calculations, offers his point of view with a simplified exhaust concept that will give some basic exhaust dimensions to start working on.

The SPJ carb from a later RS125 bike can be fitted on an earlier NF4 bike without much issues. The carb collar is a tight fit though removing the carb from the frame looks to be much easier than the stock PJ due to the shorter body. The throttle cable fitment clears the frame nicely as well. Most probably just the fitment of the carb without a proper electronic conversion from later bikes doesn't worth the hassle and the cost but it can still be used nonetheless. 

Pickit is a family of programers for PIC microcontrollers, made by Microchip Technology. The latest version called PICkit3 features a 16-bit PIC24F processor and offers a useful & convenient way for either programming or debugging PIC and dsPIC microcontrollers. Accompanying the pickit3 and available for free download is a powerful graphical user interface called MPLAB Integrated Development Enviroment (IDE).  For the connection to the PC you only need a free USB port and the pickit can be connected to the target via a header and instantly used as an in circuit serial programming (ICSP) device.  Making a simple Google search for motorcycle projects using PIC microcontrollers, you will find lots of stuff like CDI units, Quick Shifters, Shift Lights etc. and sometimes these projects include the HEX files so you're ready to program and experiment with some PICs with the help of Pickit3. 

I have a lot of backordered expansion chambers and a lot of R&D left on a electronic gizmo that I'm working on. I'm trying my best, yet still, can't organize my schedule and keep up with the deadlines and I've left quite a few people disappointed. I'm currently fabricating some Battery Eliminators, modifying and repairing PGM and YPVS units for Marti(CY), Jason(MT), Yuri(IT), Antonio(SP) & Eddi(ZA).

Next in line in the  "Low Budget" cylinder repair articles, is measuring the piston to cylinder bore clearance. There are few tools out there but keeping the budget in mind, not all of them will suit our purposes.  Hence, a quick and easy way is to use piston fit fillers, something everyone should have in his toolbox. Piston fit fillers are cheap and very useful.  You will need 0.002, 0.0025 & 0.003 inch fillers as these will cover most of your needs.  You will have to measure the clearance on a 90 degree position in relation to the piston pin. Along the "boost" port is what I usually prefer. A 0.002 inch clearance is suggested for most engines (0.05mm) but consider going up to 0.003 inch (almost 0.08mm) as this will most probably save the race!  Also check :  a)   Muriatic acid for removing piston deposits from nikasil cylinder.   b)  Cylinder honing and a few more notes on piston fit fillers in the link below Piston fit fill...