FallonDave
XS650 New Member
Just restored a 1981 XS650 Special 2. Like an idiot I only lapped the valves and didn't have them ground. I rebuit the carbs replacing diaphrams and ets and mixture screws etc. Cleaned out carb passages several times now. Problem is unsteady idle, unable to sycronize carbs, eratic carb performance. Replaced carb mounting manifolds with "made in Japan" ones. Hooked up vacume gauges and only get about 1-3" of vacume on both cylinders. I know on cars you should get around 15-20". I've seen no discussion on this subject on the 650's. My question is should I still see 15-20 " with the 650's short intake manifold run. Has anyone put a gauge on the carb hose barb and actually seen "normal values"? If so I suspect I have leaky valve seats., weak spring or other valve issues. I'm asking someone who has a good running 650 what their vacume reading is at 1200 rpm etc. I am running Uni pod filters