Intake valve getting tight

My bike was hard to start this past weekend, so I pulled the valve cover and checked the valves today. The intakes were tight. Exhaust were in spec. I reshimmed both intakes and have the proper clearance now. 2.15 shim in the left and a 1.90 in the right. Bike started easily after that. I bought the bike used, and the shim size was wore off the shims, so I don't know how much they moved. They were all in spec when I checked them the first time about 30 hours ago. My question is, now that they are moving, how muct time do I have left before I need to replace the valves? Secondly, how much am I looking at spending to have the head rebuilt? Thanks!

Thanks Dean, mine is the newer valve train. If the decomp. lever is stand alone, it is the earier valve train, if it is incorporated with the hydro clutch, it's the newer. Thanks for the link.

How many over all hours are on the bike? Do you know if they were shimmed before at all? Once they have been shimmed once, they will start moving faster& faster between each time they get re-shimmed. I'm not sure how many times you can get away with re-shimming them before the top-end should be rebuilt, but I'd guess it's only 2-3 times. (someone who knows this could chime in on this.........)

Thanks for the input everyone. I checked my maintenance log and it looks like it's only been 19 hours since I checked them last. I think I am more inclined to just have the head work done now than have to wonder everytime I ride if I'm going to have a valve drop. Going to head over and see George today at lunch.

if i had to put a # on it i would say it is safe to go down to a 165 or a 170 shim.i think it can be dangerous using shims thinner than that to acheive proper clearance.what you are describing is fairly common for this model.unfortunately you will probably be adjusting your valves very frequently untill you have valves replaced and head machined.dan