Two Stroke Racelab

Another one rare PGM unit that needed repair and belongs to Deon(OZ). It is an SPL unit for Honda Rs250 NF5, most probably for the latest 1992 model. I'm not sure what SPL stands for but I've came across a few racing parts marked with these letters and all seemed to be NF5 or NF4 parts. They seem to be special parts, similar to KIT parts for later models.

Here are some photos while dismantling the wet clutch basket. The rivets were drilled as to remove the retainer plate. The rubber cushions seem to be in very good condition, they will become handy later... Here is the wet clutch basket after removing the cushions and the primary gear. Now back to the dry clutch basket. The retainer plate was removed and a real mess was revealed. The cushions were highly damaged and this must have helped for causing the cracks on the basket. Here you can better see one of the cranks on the basket. It goes deep and very close to the mounting points for the rubber cushions and the rivets. The two clutch baskets, side by side. The modification looks pretty straightforward and to use the wet basket on a dry clutch, only a simple lathe boring operation is needed. To be continued...

Just a photo of a very rare Mugen PGM unit that belongs to Richard(UK). It had some Rc Valve issues but it is now repaired and posted back.

Greetings to all. I haven't been blogging a lot lately due to a lot of work and loss of ideas... so, it's a nice opportunity to present some work from fellow Martin.  Martin is based in Devon, UK and I believe he is contributing and helping on 2T forums for more than a decade. I used to read all of his helpful info on tuning Tzr-Tdr250 bikes and I've learned a lot from him.  He is well known for his tuning work on many Yamaha bikes but I believe the most commendable point are his hydroformed ex pansion chambers for TZR and RD bikes ., You can find Martin at "mjseventyseven AT gmail.com" and of course via the tdr250 forum . Some of his work... Tdr250 Pipes   Tzr250 1KT - 2MA Pipes   RD350LC/YPVS pipes (available to give either 9500rpm or 10,200rpm peak power).

One of the issues I had with the FCC dry clutch conversion for my Honda Rs125 bike, was the clutch basket that had several cranks on the perimeter. While still having some wet clutch parts for my NF4 bike, I started thinking on the possibility of using the wet clutch basket instead of the dry one. Front side of both baskets...  Back side. To evaluate the possibility of using the wet basket on the FCC conversion, I had to strip them down completely and take more measurements and plan the lathe and/ or milling operations needed. Let's start with the wet basket by removing the inner collar. To be continued...

I've just completed working on a custom made leak down tester to suit Nsr250 Mc16 Keihin 28mm carbs, for Karl(UK). I love working on a metal lathe.

Το φόρουμ 2stroke.gr κλείνει 3 χρόνια λειτουργίας και θα το γιορτάσουμε δεόντως!

The end can on my TZ125 was in a bad shape and needed re-packing. I had a piece of carbon sleeve laying around at the workshop, so I decided to give it a try. Inside diameter of the carbon sleeve is 60mm while the stock aluminum tube is 62mm. The flange that bolts on the expansion chamber was modified on my lathe and for the other side I fabricated a shorter stainless steel end piece. And the end results with photos of the stock and the new end can.

Leak Down tester kits for the Yamaha TZ125 4JT bikes can now be purchased via my online store. The kit will fit all Yamaha Tz125 1994 - 1997 models. Most probably it will suit later TZ125 models as well though I haven't verified this yet. The leak-down tester is an essential tool for any high performance two stroke engine. This kit is installed in place of your carburetor and by pressurizing the engine cases you can check for any air leakage due to worn mating surfaces, erratic torque values due to aged parts, worn crankshaft seals etc. It is a necessary evil that it will help prevent catastrophic damage to your engine and keep performance up. A very valuable tool for a two stroke engine, handmade with care. Directions of use:  Testing can take place after a newly assembled engine to verify that everything is leak free, on a bike you just bought and you need to check crank seals condition etc. Place the tool in the carb manifold, seal the cylinder head with a normal spa...

Another one racing story from Sakis Vasilopoulos in his own words. Sorry from the majority of my visitors but it's in Greek language. Γεια σου Νικόλα,  για μια άλλη ακόμα φορά ξεκινήσαμε για την μακρινή πίστα της ROAD AMERICA,ELKHART LAKE WI.  Απο το σπίτι μου μέχρι εκεί 1473 μίλια (one way), για να φτάσεις μέχρι εκεί πρέπει να διασχίσεις τη FLORIDA,GEORGIA,TENNESSEE KENTUCKY ,OHIO,INDIANA,ILLINOIS και μέρος από το WISCONSIN! Φύγαμε Τετάρτη και φτάσαμε Παρασκευή! Χάσαμε τις πρωινές δοκιμασίες αλλά μπήκαμε στις ελεύθερες το μεσημέρι για να τσεκάρουμε για τις επίσημες του Σαββάτου με τον Maik Τα προγνωστικά μιλούσαν για βροχή το Σαββατοκύριακο και στις δοκιμές του Σαββάτου το μηχανάκι δεν είχε απέλαση! Ψαχνόμουν με τα ζιγκλέρ και αντί να το φτιάξω το χάλασα! Στον αγώνα δεν περπάτησε και τερμάτισα 3ος, το Σάββατο το βράδυ το έφτιαξα αλλά τη Κυριακή άρχισε να βρέχει και να φυσάει. Μπήκαμε στις δοκιμές το πρωί με βροχή να τσεκάρω jettings, gears κλπ. Γλίστραγε παντού, η ...