TZR125 2rh Posted September 25, 2013 Share Posted September 25, 2013 Hi all! (I feel like a foreigner amongst all you Yam owners, Kwaks are normally my thing) Until now! Right! So looking for help, advice, info! Currently rebuilding the above Teezer, got the engine back into the frame and ignition electrics all wired up, wanted to make sure the motor was sound before i progressed, (had the engine split to do the crankshaft oil seals) Anyway, rigged up a temp fuel supply and she fires on the 5th kick! Revved and idled perfectly! Engine sounds tight and sweet with no rattles! Next day decided to tidy things up and noticed 2 "O" rings in the gasket set packaging! Ah! Power valve seals! No probs, a couple of allen screws and "O" rings fitted, Kicked the engine over and there seems to be a small knock/rattle! Now this is a fixed power valve(no cables or servo) and it only has 2 positions from what i can see, position 1 and postion 2 which is 180 degrees round from position 1. Both positions still produce the same knock/rattle! Removed the power valve and it runs very close to the piston and rings(both still intact) considered removing the cylinder head and barrel to check the piston and rings but before that, i removed the powervalve and kicked the engine over, No knock or rattle! (baffled now) i'm guessing the powervalve is just scuffing the piston as it's running through it's cycle! Where do i go from here? I can find no reference anywhere to powervalve setup and position except for the servo operated ones! I really don't want to run the engine and risk damage! But if it's normal then so be it! Help me out guys! Apologies for the long winded posting but the more info i give then the better the solution! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted September 26, 2013 Moderator Share Posted September 26, 2013 There are folks on here better able to answer but pv to piston contact is not that uncommon. Normally shows in a hot engine though, generally results in busted rings and a big chunk of the top of the piston coming away. You need to work on the piston to pv clearance. Being a static valve simply radiusing the piston side of the pv should sort it. Link to comment Share on other sites More sharing options...
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