Timing Question

[Hans Hergesheimer]

Today I started my a valve adjustment on an 05 S2R (800cc, 2V) and noticed some interesting things.  I am using a crankshaft turning tool, fitted through the inspection cover on the alternator side.  I turned the engine over until the horizontal cylinder was at TDC, using the mark on the timing belt driveshaft pulley.  At this point, the mark on the flywheel, seen through the sight glass in the alternator cover, did not line up as described in the service manual.

In order to check things again, I turned the engine over until the horizontal cylinder was at TDC by plugging the sparkplug hole with my finger and then narrowed it in by feeling the top of the piston with a screwdriver and slowly advancing the crankshaft.  (this took two people).  Using this method, the marks on the timing belt driveshaft pulley and the clutch cover lined up, but there was no mark visible through the alternator cover.  As near as I can tell, the mark it should line up with on the flywheel and TDC for the horizontal cylinder are approximately 10 degrees apart.

I checked all of my clearances for the opening and closing rocker arms at both points, but noticed no real difference between 10 deg before TDC and at TDC.

Is this discrepancy between the flywheel marks and the timing belt pulley something I should worry about remedying?   If not, I will simply use the marks on the timing belt pulley since they actually line up correctly.

[theducatikid]

I've only done one valve adjustment on my 620, so my experience is pretty limited, but this is what I noticed:  the timing marks on the pulley aren't as exact as the flywheel marks.  Try getting close with the pulley marks then line up the marks on the fly wheel.  Now look back at the mark on the pulley,  you'll notice they are still close to being lined up.  As long as the aren't off by an entire tooth, you should be good to use the flywheel marks.

[uclabiker06]

if the three marks on the timing cams for the belts all line up you have horizontal TDC.  Using your finger to feel the air right before TDC is a good idea.  Another technique people use is to put a screw driver through the spark plug hole to check for TDC.