After having a lot of starting and running issues I gave our 99 Breeze a tune up, changing plug, rebuilding carburetor and adjusting the valves. Now it starts very easily and runs great but it now has a valve clatter that it didn't have before. I have double and triple checked the valve adjustments but can't get rid of the clattering of the valves. Any ideas???

 

It could be the valves have been tight for so long, you got used to not hearing anything while it was running. Yamaha air cooled motors do have a tick to them when they run, I have heard that noise on Warriors and my 95 Wolverine, even with the valves adjusted to spec. You should not hear a "clatter" , but a steady softer tick is pretty normal with an air cooled motor. Just make sure you had the motor right on TDC when you set the valves, and did you get a good "snug" pull on the feeler guage when you tested for proper gap? I like to run mine so there is a little resistance to pulling the feeler out, that way you know it wont be on the looser side, even .001 or .002 loose will make a big difference in noise output.
The fact that it starts and runs much better tells you the valves have been off for quite a while, so it sounds like you are on the right track.

 

Thanks 95Wolv - Since my original post, I did go ahead and check them again and take the valves down to the minimum spec with good resistence. Now it sounds pretty much like you are describing. I appreciate your input as it makes me more sure of what I was suspecting too. Happy New Year.

 

Glad I could help, and Happy New Year to you too !!