tick tick tick 150 cc gy6

[rks]

Well, now you have opposing opinions. I like ticking....some like things a bit tight

.004 and .005 are the right settings, and as the engine warms up to normal operating temperature these gaps will decrease. They will also very likely decrease over the next 2000 miles of operation, depends on how new your scooter is. I've found that they will hold an adjustment longer, once you get past the first 2500 miles or so.

At a leisurely 6000 rpm cruising speed, your valves are opening and closing 50 times a second. At idle, they're working 13 to 15 times a second. How you can achieve a gradual opening, or a gentle closing of the valves, at those speeds.....I don't know.

Little or no gap doesn't leave much room for oil to get between the moving parts. Maybe an extra .001" will provide a little better lubrication.

As a side note....my BMW's are air cooled, 2 cylinder, overhead cam engines, with 4 valve heads.....Gap spec for these engines...intake .006", exhaust .012". Valves make noise...tick, tick, tick. Thing is, they will do this for 100,000 miles or more. Some make 200,000 miles before a rebuild is in order.