Yeeeeeup, the Rcexl CDI I got from ZYHobbies is defective. Put a CH CDI on the 200Ti and it runs perfect. Nice increase in fuel economy over GI too. Now I can move on.

Interestingly, it spools up a Xoar 18x8 lightning fast from idle, similar to YS 4S engines, but only reaches 7350 peak rpm. Advancing the timing from 33° to 34° offered no increase in peak rpm but no detonation even when overly leaned either.

Typically when I see super fast transitions like this I also see over revving, reaching max peak rpm rating for the engine, and prop for a little more static load. Not so with the 200Ti.

PRODUCT SPECIFICATIONS

Type:4-strokeDisplacement:2.00 cu in (33.00 cc)Bore:1.10 in (28.20mm)Stroke:1.03 in (26.40mm)Cylinders:Inline twin, chrome platedEngine (Only) Weight:51.5 ozCrankshaft Threads:M8x1.25mmBenchmark Prop:17 x 8 APC @ 8,900Prop Range:16x8 - 18x10RPM Range:2,000 to 9,200Fuel:10%-30% syntheticMounting Dimensions:160 x 110 x 142mmMuffler Type:PipeCylinder Type:16.5cc x 2 / AACCarb Type:Barrel, 2-needle valveCrank Type:Ball bearing