Two Stroke Racelab

An interesting event will take place in Greece on 09th of September. A regularity rally at Tatoi Circuit, an old racing circuit that is now abandoned.  A festival that will host lots of all time classic cars and motorcycles and many veteran racers.  Hopefully there will be a lot of two strokes in there, like air-cooled RDs and maybe a TZ750, H2R etc.  More info at  classicbike.gr

The Honda Rs125 was about ready for it's first start up, so that was another great opportunity to call some friends for beers ...and help push starting the bike in the meanwhile.  Everything has gone well except a fouled spark plug at the very beginning but the bike started barking again and made a couple rounds around the block. Everything looks to be in perfect working order. Success! Next things in the wishlist, a Vertex piston a handmade expansion chamber some stickers.  Big thanks to all my friends for helping out.  Cheers!

It seems like I'm slowly reaching the end of the NF4 project and the first start up is close enough.  Here are some pics of the progress so far.  I've managed to find the suitable water hoses as they were missing except the lower one that was replaced by an aluminum tube bended to shape. For more info on how to fabricate-form aluminum tubes for use as water hoses, use the search function of this blog.  All electronics in place, turned the wheel in gear and yep... there is spark at the plug.  Aluminum Renthal sprocket, DID chain and the regular blah blah...  Keihin PJ38 carb, lovely view... note the clear vinyl hose behind the carb, it is the crankcase breather and Honda uses the frame to act as an oil catch tank. Tidy and minimal. The virtuousness of a racing 2T single cylinder bike. A few things left here and there like bleeding the brakes, pour some oil on the front forks, mounting the '95 nx5 ferings etc.

Not the kind of posts that I do but the good company deserves it... More beers for Nick, Thanos, Harry and myself at RoadHouse Rock Bar. More food as well. ...and Harrys keep ruining my photos and keep calling me a moaner. LOL Cheers for the NSRs... ok and for the Aprilia Rs250 as well. 

I've spent some time with the NF4 project and I believe the engine is now complete though still needs some minor work here and there. According to the porting theme, the cylinder is a '94 model and has a new nicasil plating from the last owner with the cross hatching markings still visible in there. After some chamfering work it's ready to be installed on the cases.  Piston to cylinder clearance is 0.09mm so it's out of spec and ring gap is 0.42mm hence really close to service limit as well but do not exceed it. I will still use it for the first start up as to verify any possible issues with the rest of the bike e.g electronics etc After a few minutes the engine is complete... ...thought the leak-down testing showed a major leak on the reed valve assy.  I'm really thankful I didn't had to split the cases and after a couple more tries to seal the reed valve the leak down test got a stable and healthy me

First link by George Kitsos(GR), a racer with multiple awards in the Greek racing champion.  Currently racing on a Honda Rs250 NXA.  Check out his site at  www.kitsos1.gr Second link by Akis Tsokos(GR), another one great racer, currently racing on a Yamaha '99 TZ250M bike (ex-Matsudo's bike, Kurz Team). Check out his site at  www.tsokosracing.gr Last but not least, a great blog by Petros(GR) aka Manivesto, with many interesting pics about his beloved theme... the Vespa & Lambretta scooters.  Everything about Vespa events taking part in Greece, from carefree coffee pics up to track days!  Check out his site at  manivespa.blogspot.gr

Here is my new set of expansion chambers for the Nsr250 bike. Well, it seems like there is still some work involved 'till I mount them on the bike. LOL Anyway, 0.7mm mild steel sheets and ...here we go again.

Another one nice fabrication by Spyros(GR) aka Bismarck. This billet aluminum ring on top of the Nsr250 cylinder head allows for precise mounting on a lathe hence machining work is possible.  Original inspiration taken out of Winton's Nsr250 blog, check out the related link at  edetuckracing, setting the squish .

In 1974, Agostini switched from MV Augusta to Yamaha. That's the time when Yamaha asked Castrol to develop a synthetic oil that would beat Castrol R by lubricating the engine more effectively, adding power and helping to combat engine detonation. The result was named Castrol A747... an almost 40 years old formula that still keeps rocking.