Drag on rocker VS feeler guage

[chipripper]

Hello all!

I am setting the closing clearances for my valve adjustment, with the opening rockers removed. I feel a slight drag when the cam lobe contacts the closing rocker arm. What I don't get is, I can fit a .002 feeler under the shim when I load the rocker arm.  I'm so cornfused. I think I need a break from all this measuring and mm to in conversion.

TIA

[koko64]

How much drag on the feeler gauge? A tight fit?

[chipripper]

Nope. .002 is smooth .003 is tight. Very light dragging where the cam lobe  first contacts the rocker.

[Howie]

A good method until you get the feel is the "go no go" method.  In your case, a .003 should be obviously too tight and an .001 loose.  anyway, sound like you got it.

[chipripper]

So just to be clear..

.002 is OK but not ideal for the closer. I shouldn't worry about some drag on the CAM lobe, as long as it does not bind?

Sorry if I'm being dense, I'm wrenches down and well into Sat night

[EEL]

So nobody mentions this but I'll throw it out for your future reference.

This will apply from a fully cold motor.

You obviously don't want to get to this point but if you do this will help diagnose your issue. Once you button up your engine and run it, you can tell a few things from how the bike idles:

1) If the idle bounces up and down while the bike is cold and then settles to a stable idle once warm, your valve clearances are too loose (most likely your closer)

2) If you idle is stable when cold and then stutters with some hesitation after warmed up (almost like its going to stall) your closers are too tight. Do NOT run this bike PERIOD until your have fixed the issue.

If the latter occurs, lather rinse repeat with measurements.

This is from my personal lessons learned from past experiences with adjustments.

[EEL]

So to get this straight in my head. When you say opening rockers removed. Do you mean you shifted them to the side or you physically pulled the rocker pin and are holding them in your hand?

If the latter, then spinning the cam lobe fully should not have drag. If you do, you're tight somewhere.

I ran into this issue as well in the past. The feeler fits but spinning the cam lobe results in drag. What I figured out was that the closer tolerances are so finicky that the shim thickness itself is sometimes different on one side of the bottom of the shim vs the other side.

This can occur from sanding down a shim by hand, not having a level surface or  having a portion of the sandpaper worn out while exposing the other half of the shim to a relatively untouched section of the sandpaper.

Do this. Rotate the closer shim clockwise by 45 degress and then spin the cam lobe again. See what happens. Do small increments and see if your drag disappears. Also try to measure the clearance with your feeler gauge and see if it changes.

Due to cramped working area, a lot of the times you can only measure clearance on one side of the shim. Rotating the shim will give you a better and more accurate profile of the entire shim surface.

[chipripper]

I will check that out EEL. I abandoned this project for XMAS, but will be getting back into it this weekend.

I did completely remove the opening rockers, since the DS1000 doesn't let you move both rockers to the side at once, and I wanted to be able to fully rotate the CAM and feel for drag. What I think I noticed was there are tight spots on the CAM lobe, where it first contacts the rocker (that is where i feel the drag), but it feels OK once I am on the face of the lobe (where I did my feeler measurements). I read a few posts from bradblack indicating the tight spots at the beginning and end of the lobe were common on the s2r, which seems like a bad design, since if you set .000 for the tight spot, it will be slightly looser for the duration of the valve opening. You are definitely correct about the measurements being finicky as you approach the .000 clearance. I have a few weeks to get it perfect, since I am also stripping and polishing or re-painting my valve covers and some other bits at the same time.

[EEL]

I'm stripping mine down this week as well and plan to pull the open cam lobe. Here is what I would do. Put a smaller super loose shim in on purpose and see if the drag dissappears. In order to get it perfect you most likely had to buy a new shim anyways. So the old one is probably still sitting around.

I have never seen a closer get tight over time, usually just looser so try putting it back in and see what happens. This is of course if you didnt replace the retainers as well (with new half rings or MBP collets). Then you may have regained clearance you didn't have initially.

[ducpainter]

To go along with what EEL is saying...half ring orientation is crucial. The half rings 'wear' in and show wear on the valve side.

If you flip one over it will close up the clearance by about .001...for about 5 miles, and then you'll have that loose closer all over again.

[MonsterHPD]

To go along with what EEL is saying...half ring orientation is crucial. The half rings 'wear' in and show wear on the valve side.

If you flip one over it will close up the clearance by about .001...for about 5 miles, and then you'll have that loose closer all over again.

To get rid of this problem, as well as doubling (at least, I think) clearance adjustment intervals and eliminating broken half rings, I now have MBP retainers on all my motors. I think I've never had a service with not at least one broken half-ring .... but then all my bikes are also used on track.

DSC_0375 by torbjörn bergström, on Flickr

[ducpainter]

I have the same problem with broken half rings.

I still haven't made the switch to MBP.

[EEL]

I have the same problem with broken half rings.

I still haven't made the switch to MBP.

I switch to MBP retainers and EMS closer shims after the first adjustment. Since the MBP have a different profile, the existing shims have a weird groove from the half rings that impacts the closer measurement.

EMS shims have never let me down. From experience, I've been able to bump up the adjustment interval to 10,000 miles without any issue.

[Speeddog]

I see broken half rings mostly on 620's and DS1000's.
My conclusion is the first is due to getting revved higher than the larger engines, the second due to a large valve with a tiny stem.

I've been running my M750 with MBP's for nearly 20k miles, and it does hold adjustment better.
Exhaust closing clearance still grows, mostly due to valve/seat wear, IMO.

[MonsterHPD]

Well, I'm not sure if the M800 has broken any half rings, but all other have. The 909 SSie track bike was worst. The M900 also broke them, but not as consistently as the SSie in spite of agressive VeeTwo cams and 9300 rpm rev limit.  The 1100 broke all rings on the inlets, in spite of not very many track days. The inlets usually goes first; heavier valves, I suppose.