Yamaha Starbike Forum banner

950 valvetrain racket

2K views 9 replies 4 participants last post by  Mattbastard 
#1 ·
Does anybody else's 950 have a certain light clatter from the valvetrain everywhere but idle? Kinda sounds like a Sportster up top, like an old sewing machine.

I did the 16K adjustment, no idea if they were off at first, I just loosened the nuts and adjusted them all to spec from there. I can't say I noticed it before, just lately it seems a little clattery.
 
#2 · (Edited)
when they are properly adjusted they will tap loud enough to hear them. You hear it more if you have a windshield on the bike, it reflects the sound up to your ears more.

When you dont hear them tapping then you have to worry they are too tight.

Did you let the bike sit overnight and adjust the valves with the engine stone cold? (say yes) If you ran the engine at all and then adjusted the valves, they wont be right.

Next time you check them see if they are within spec before you loosen the nuts. If they are in spec there is no reason it loosen the nut and set them again.

Last time I checked mine they were fine after 12,000 miles since the last check.

Also, make it easy on yourself - there is a range that is acceptable. For example if the intake is suppose to be within 4 to 6 thousands, if the 4 gauge will slip thru and the 6 wont - you are good. Some people try to get the exact snug feel on the middle gauge (5 in this example). Its a waste of your time, the engine runs over a wide range of temps, if the spec is 4 to 6, then thats close enough.
 
#3 ·
Engine was cold enough to freeze the balls off a brass monkey. (Google it)

I even lined up the TDC marks with the two little windows for F and R cylinders.

I have a windshield so that makes sense. Since I know valves tighten over time I set the feeler at the widest acceptable dimension per valve, spun the stud down into it, then set the lock nut. I suppose that may add for some audio to the valvetrain.
 
#8 ·
Tappets gonna tap
Alligators gonna alligate

(they actually named them tappets!)
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top