Hi all, I've a new to me 86 TLR200 with a severe off idle stumble when I whack the throttle. So far I've set the valves (new timing chain also), set the decompression cable and throttle free play, cleaned and regasketed the carb including cleaning all jets and orifices, and set the float level to 24mm.
Relative to carb adjustments the air screw is at 1 3/4 turns out, and I've shimmed the needle by 1/16 inch spacer.
The problem is two fold:
1. on idle it doesn't return to a low idle quickly when warm. When cool (1 minute idle) with the choke off, idle is good.
2. as the engine warms the off idle stumble gets worse. I believe it to be a too lean condition as if I open the air box a little (using a wedge and tape on the air box cover) the stumble is worse.
I have read about the xr100 carb swap and drilling the jets but these two solutions would be a last resort for me. Any advise?