Gas tanks curing in the sun

BARNEY’S JOURNAL

October 14, 2007: A Look at the Timing Chain Area

With the engine on its right side, before the covers are removed.

With the generator cover off, the rotor and stator are visible.

Rotate the crankshaft to TDC of the compression stroke. Both valves are closed.

A closeup showing the "T" TDC mark on the generator rotor.

Points cover off showing the points.

Points removed showing the advancer unit.

Advancer removed, now showing the oil seal (which leaks) and will be replaced.

Oil seal and left camshaft bearing plate removed, exposing the cam sprocket.

The cam shaft removed, showing the timing mark on the sprocket aligning to the notch in the head!

So the cam chain is correct, but it is at the end of its adjustment travel so should be replaced,

The camshaft has rough surfaces where it "doesn't count".

Is this normal, since all the aftermarket and eBay cams seem to be smooth all over?

Now as to the question of top end gaskets, how does one determine which ones one needs? The good Dr. at http://dratv.com/topendgasset1.html shows two different head gaskets for the CT90 (dare I say S90 too)? My guess is I have the old one? Any comments? I am hoping to get the answer before I take the head off. Since I am hoping I don't have to, and Barney will run and not spew oil all over the place :-) If it does then I will need a correct top end gasket set.

So Jack if you look at this (:-) I have an E1 head with 89cc stamped on the iron barrel. Do I get the old gasket?

But when I see this "Permatex-like" stuff...

This is the cylinder - cylinder head joint. Looks like a lot of goo instead of a correct cam chain top gasket and the oil seal on the stud, etc. (?) and goo on the bottom too, so looks like a top end gasket set would be good?

Now back to the crankshaft end of the cam chain.

Notice the clear mylar wrapped around the rotor. This assists in removing and replacing the stator. It helps prevent the stator cores from being grabbed by the magnets in the rotor. This is similar to the trick from Bob 'n' Shirl down under somewhere, I think, for passing the camshaft oil seal when assembling. Message #67551 in the Yahoo! CT-90 group. Thanks, I will use it on the kick starter shaft oil seal (if I can) and the gear shift shaft oil seal (?) too.

Another picture of the mylar sheet between the rotor and stator.

Now at TDC, note the position of the cam chain tension adjuster.

Is Bailey right? Is the adjuster at or very nearly at its limit?

Another shot from below showing the chain.

Now my shop manual says 70.4mm but I measure about 38mm for spring length with no tension?

It seems to push the adjuster all the way with no problem? So is this correct for an S90 (or CT90, CD90, C90, CL90, CL90L) engine with this adjuster configuration? That is, one with no adjustment possible. I will be asking all these question in the yahoo group :-)