Not with an OHC motor. Cold is loose.
Nah - Yours is a 1300.You all see my beat bike you would think George was riding it!
But, doing the checks does not insure they were done right. I am not saying you did not do it right, just no way of knowing if I were to buy your bike.Would anyone want to buy something from someone that neglected recommended maintenance?
It is the valve SEAT that wears, This causes the valve to set further in the head which decreases the gap between the valve stem and the cam/ tappet.I confess that I did not perform my first check until 28k miles. I found one exhaust and one intake valve that were both 0.001" out of spec. I installed correctly sized shims and buttoned her back up, and I don't plan on doing the next check until about 56k miles. But realizing the valve gaps had shrunk over time got me to thinking ...
If one studies the geometry of the ST1300 valve train, one may wonder why the gaps get smaller (tighter) with use. One would tend to believe the gap would get larger with normal wear. Unlike an engine with rocker arms, the ST1300 V4 valve components are all in line, directly on top of each other. The camshaft imparts a force down onto the tappet, which then transfers that force through a shim onto the valve stem. If any of these components exhibited any wear, the gap would increase with use ... but ours decrease with use.
The camshaft lobe, tappet and shim are not "growing," so what's moving? I doubt the valve's stem gets any longer when it's subject to repeated compression forces. The only thing I can think of which may move is the valve seat in the aluminum head. After a valve has been pounded shut a few million times, it's conceivable that the seat might get hammered deeper into the softer material of the cylinder head. After continued use, the seat is hammered no further into the cylinder head because the softer material has been compressed as far as it will go. And THAT is why I believe the initial valve checks are the most important.
Doing a valve check can be a laborious task, but the peace of mind it provides is priceless.
The first part of your statement is true...but even with aluminum heads, the valve seats are hardened steel, pressed into the aluminum head. So the hardened valve seals against the hardened seat. Even with both hardened steel parts, though, closing thousands of times a minute takes its toll. Very slowly, over time, the valve and seat wear and the valve sinks deeper in the seat (and, therefore, in the head), closing the valve to cam lobe gap.It is the valve SEAT that wears, This causes the valve to set further in the head which decreases the gap between the valve stem and the cam/ tappet.
A hardened steel Valve and a soft aluminum Head.
The ST1300 gaps must be measured with the camshafts in place. The only reason one would need to remove the air-box is if any shims need to be replaced on the starboard (right hand) cylinder bank. That's because the chain tensioner for the starboard side is under the air-box, between the cylinder banks, whereas the port side tensioner is very easy to access. Thankfully for me, both of the shims I needed to replace were on the port side.If they actually did need adjusting the procedure seems very tough as you not only have to remove the cams but also the air box?
Jim,Randy- a little secret- I'm trying the "flat rate method" (auto tech term to describe taking shortcuts to save time and/or labor). I was able to get all the shims and buckets out of the exhaust side without even unhooking a cam chain by carefully tilting the exhaust came up from the rear. I can't comment about how easy/difficult it will be to reassemble until my new shims get here. At most I expect to loosen the cam chain adjusters, seat the cams back down, and torque everything to spec. If that is the case, I should be able to do a valve shim job from start to finish, including the initial check, in under an hour. And this is the first time on an ST1300 for me. Next time should be quicker if I can keep the bike.
Jim