Now that you have managed to figure out where neutral is, get that battery disconnected.  Don’t be working in that primary case with the battery connected.  These rascals have a nasty habit of automatically energizing the starter motor (some anomaly with the decompression relay).  Always best to disconnect the battery when working on the engine.

Nice job on the clutch release cam.  No big deal on the o-ring.  By now you have probably figured out that removing the clutch cover is an easy job.  If that particular o-ring leaks, it is merely a housekeeping issue.  It will be a very small leak and won’t degrade oil pressure to anything.  Up to you if you change it or not.  Regarding the clutch push piece o-ring, you should probably change that one.  It affects oil pressure to the trans & clutch.

The play in the fitup between the release cam and the release shaft is something you have to evaluate on your own.  One way to get a better feel for how much play is in there is to push down on the release cam such that it is hard against its stop in the clutch cover, then gently twist the release shaft back & forth while you hold the release cam against the stop.  Any lost motion will be evident.

The yellow arrow points to the stop.

If the release arm is situated too low, you need a shorter pushrod.  If the arm is situated too high, you need a longer pushrod, or you have too much play in the fit between the release cam and the release shaft.  If there is too much play between the shaft and the cam, shimming may be required.  Let us know what you figure out.

Once you know the as-found condition, you can remove the clutch cover and disassemble the clutch.  Inspect all the plates, measure their thickness, and clean them in new Rotella.  Just use an old toothbrush and clean Rotella in a shallow pan.  Scrub it all up and measure all the plates.  I bet they are all just fine.  Take some pics so we can see.

Put it all back together and reinstall the clutch pack.  It will be good practice and only takes a few minutes.  Then reinstall the clutch cover and gasket and confirm your pushrod situation.

Some tips on the clutch assembly:

Take a mill smooth file and dress down all the sharp edges on the clutch hub nut.  Those sharp edges dig into the soft lock-tab washer and mess up your torque when you tighten the nut.  Be very careful with the torque on that nut.  Never use a rattle wrench on it, and don’t exceed 50 ft-lbs.

See how all the edges on this nut have been rounded off so that they are not sharp.  Just break the edge with a file.

This sketch shows the orientation.  Note that the sketch doesn’t show the fiber plate.  That outer fiber plate is different from the other five plates.  It’s a bit thicker, and the hole in the center is larger to accommodate the wave washer assembly.

Thanks Mike!

Battery was promptly disconnected and returned to the bench.

Yup, I'm missing the important bolt that holds the side stand to the frame when the cap nuts on the long motor mount bolts running thru the case are loosed to remove the right foot peg, brake assembly and heat shield (causing my shifter and entire assembly to feel wonky).  I knew something wasn't right because this didn't happen on my last S40 when I removed those 2 cap nuts.  I almost dropped the bike on its left side when I was getting the bike on the stand.  Thanks for this catch!  I was able to get the bolt added to the parts order I placed yesterday.

I bought a cheap snap ring plyer set.  Now I need to figure out how to use it.  It has 2-straights, 1- 45, and 1- 90 degree.

Sorry for my confusing comment about the oil hole in the exhaust lobe.  Attached are a few endoscope photos of what I believe is TDC on the compression stroke.  Both sets of valves are closed, rocker arms wiggle, and I can see the oil hole in the exhaust cam lobe (photo attached).

Exhaust Valves Closed.

I bagged off the clutch pack and gear area in the event I might drop the little C-clip.  Put an old kitchen cup towel in the bottom to catch little parts and keep the area free of debris.

DragBikeMike wrote on 12/17/23 at 18:47:24:


When I checked this before surgery, it rested (tilted slightly) towards the top of the range markings but still within the range.  My push rod is the 45.5mm length.  I'm inclined to leave this as is and just roll with the 45.5.  I see no visible difference in the stock vs Sneeze cam release that would suggest a different length push rod is needed.