Trouble with Valve Clearances

[klous-1]

Hi guys,

I have adjusted the valve clearances on my YBR 125 (EFI), and now have problems.

If I set the inlet valve to within tolerances, when cold it seems to run rich, any opening of the throttle and the engine splutters and dies. It ticks over slow, but adjusting the idle screw doesn't help matters.

So I have to increase the valve clearance, but of course get a horrible loud tapping/clicking. Runs OK, but still doesn't start great, power and repsonse seems ok, but worried about ruining the engine on this long trip.

I'm in Kenya, wondering if it is a coincidence that just before the adjustments I filled up with fuel, so maybe bad fuel?

Should I use two feeler gauges and set both valves at the same time?

Or some ideas?? Would be greatly appreciated.


Have taken it to Yamaha dealer here too, who checked the valves, which were ok he said (but he wasn't the greatest mechanic), by which time the engine was warm anyway of course and so started ok.

Stumped. Should have left well enough alone!

Thanks,
Nick