Backfire & Valve Clearance Questions!!!

A buddy of mine just purchaced a 93 650L that has 30,000 miles on it. It ran great but smoked like a train when first started. After a few rides he started complaining of a tick in the valves so we adjusted the valves. The tick seemed to stop, but now there is a loud sharp backfire on decel. I rechecked the exaust clearances tonight and they were a little tight so i backed them off a little but still backfires. also when it backfires i notice a puff of smoke out the tail pipe. could the intake clearances be off????? any help would be appreciated thanks!!!!!!!!!!!!

I would look for an exhaust valve on it's way south (burnt) ... do a compression test ... :ride:

If it was not backfiring before you adjusted the valves, I would recommend rechecking the rocker clearances again.

If the valves are set rite try making the idle a little richer.

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