tdm900 Posted July 1, 2007 Report Share Posted July 1, 2007 I recently bought a cracking TYZ 250 and there is one thing that is intriguing me. It has got the number "18" stamped into the top of the headstock, just in front of the radiator cap. Does anyone know what it signifies, if anything? Quote Link to comment Share on other sites More sharing options...
steveo Posted July 2, 2007 Report Share Posted July 2, 2007 Checked mine, and it is clear, no numbers or letters. Quote Link to comment Share on other sites More sharing options...
garyp Posted July 3, 2007 Report Share Posted July 3, 2007 I recently bought a cracking TYZ 250 and there is one thing that is intriguing me.It has got the number "18" stamped into the top of the headstock, just in front of the radiator cap. Does anyone know what it signifies, if anything? Ibought one a couple of weeks ago, looked at mine and ive got nothing stamped on it. Gary Quote Link to comment Share on other sites More sharing options...
tdm900 Posted July 4, 2007 Author Report Share Posted July 4, 2007 (edited) Woody seems to be the font of all tyz knowledge on this forum, are you reading this ? Have you any idea? Edited July 4, 2007 by TDM900 Quote Link to comment Share on other sites More sharing options...
djscooby2007 Posted July 4, 2007 Report Share Posted July 4, 2007 it could just be like a tag as mine as the old owners postcode stamped in. do you guys know where i can get parts such as top end gasket kit piston ect...? thanks Quote Link to comment Share on other sites More sharing options...
tdm900 Posted July 5, 2007 Author Report Share Posted July 5, 2007 it could just be like a tag as mine as the old owners postcode stamped in.do you guys know where i can get parts such as top end gasket kit piston ect...? thanks piston - http://www.jkhirst.co.uk/acatalog/Pistons_Rings_Pins.html gaskets - http://www.jkhirst.co.uk/acatalog/Gaskets.html not cheap though !! Quote Link to comment Share on other sites More sharing options...
djscooby2007 Posted July 7, 2007 Report Share Posted July 7, 2007 hi if you havent guessed im new to trials and i am now woundering if my bike is ment to rattle a bit or is there somthing wrong??? thanks everyone Quote Link to comment Share on other sites More sharing options...
woody Posted July 7, 2007 Report Share Posted July 7, 2007 Sorry, no idea what the number 18 signifies. Perhaps Nigel Birkett may know if some were stamped for any reason, he's your man for anything Yamaha. Piston kits are generally a reasonable price, but if the barrell needs replating then that costs a bit. Head gasket is pricey. The TYZ shouldn't rattle so something is worn but obviously impossible to say what, could be piston, small end, big end or all three. It's an amazing motor the TYZ, they really will take some abuse. My Birkett framed TYZ suffered a heat seizure on the road in the SSDT after a blown head gasket let all the coolant out. It was locked solid and very, very hot. After it cooled down I filled it back up with water, managed to free it off and kicked it up. It had no compression so I guessed the rings were stuck but it started and got me back to Fort William. Fitted a new head gasket and managaed to get another couple of days in before I retired as it was still losing coolant and I didn't want to damage it too much or get stuck miles from anywhere. I didn't want to get spat off it on the road either if it locked up again as one near miss was enough... When we took it apart after getting home we couldn't believe what a mess it was inside. The mains were gone, so was the small end and big end and the piston was worn. Parts of the plating on the bore of the barrell had picked up and embedded themselves in the piston in several places and the rings were also welded into their grooves in a few places, the bottom one probably 90% stuck, both of these due to the heat seizure when the head gasket went. Despite all this the bike was still running fine, wasn't rattling, just a bit of a grumble from the mains and it was still pulling like a train with no apparent loss of power. It was still pulling 4th and 5th up the sides of the mountains on the moor crossings no problem and showing a decent turn of speed on the road. Looking forward to seeing what it goes like when the rebuild is complete Quote Link to comment Share on other sites More sharing options...
djscooby2007 Posted July 8, 2007 Report Share Posted July 8, 2007 ive checked the piston small end and big end and they seem ok so im baffeled Quote Link to comment Share on other sites More sharing options...
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