HELP NEEDED

JUST STARTED THE BIKE UP READY FOR MORTIMER, RUN WELL UNTIL REVED HARD, NOW STARTED TO RATTLE EVER SINCE. STILL RUNS AND TICKS OVER NICE, BUT STILL HAVE ENGINE RATTLE AND IT SMOKES A BIT. BUT THROTTLE IS STILL RESPONSIVE. ANY IDEAS!! HELP US QUICK!!!! :)

What engine do you have? If it's a Yam and the rattle is from the top end, think cam chain or small ends. Other options are valve clearances, and if it's smoking maybe a sticking valve or valve stem oil seals.

DO YOU THINK ITS WORTH TAKING TO MORTIMER? THINK RATTLE IS FROM THE BOTTOM END. `

Does the rattle reduce or go away with the clutch lever in Gilo?
If so it could be a broken plate or spring, or the clutch nut coming loose. Or you may have just fooked the mains, lets hope not.
May be worth giving Rob Wilky a ring in the morning, he's a good lad and good with the yam engines.