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Reassembly of the CB350 Motor Begins

Careful measurement of critical parts showed all within service limits, so it was time to start the reassembly.


I coated the pistons with assembly lube and slipped the rings down into their grooves. I made sure that the mark (a Capital "R") was up on the top two rings. I checked the groove clearances by trying to slide a feeler gauge of the thinnest spec for all three rings into the grooves beside the rings and it would not go into any of them. Good to go.

Next, I inserted the piston pins and locked the pins in place with their circlips. I made sure the arrow on the top of the pistons pointed toward the front of the engine as I did this. So far, so good.

Now, I turned my attention to remounting the oil pump and clutch. (A hint here if you find yourself trying to do the same thing: make sure the main drive gears that go behind the oil pump are stacked so the flat sides of each are facing away from each other. The slightly beveled edges should be facing each other. It is hard to tell in photos, but the teeth of the two gears on the back of the clutch basket are slightly offset. If you don't put the main drive gears in properly they will not mesh with the clutch. I had great pictures illustrating this, but of course, they have disappeared into cyberworld, their hiding place known only to themselves.) My "complete" engine gasket set did not come with a gasket to go behind the oil pump, so I traced the oil gasket on a piece of white paper then transferred this to some sheet gasket material This new gasket I then mounted behind the pump.


Once the rear basket/gears and oil pump/gears were installed, I reloaded the clutch with the disks and other basket and tightened it all down with the bolt/spring/washers.

But here I came to a screaching halt. I laid out all the main gaskets to make sure I understood where they all went and how they would fit when I saw that the new head gasket would not accomodate the red o-ring that had come off the old. This is troubling becasue the Clymer manual says to make sure you put these o-rings (new) in or the assembly will leak. Of course, the Honda manual doesn't mention them or show pictures of them. Hmm. What to do?


Below are the two gaskets side by side (old on top) and you can see that the hole in the old gasket is much bigger than in the new, and in the old those little red -o-rings nestle in perfectly. I may seek advice on this situation or simply recut the hole in the new gasket to accomodate the o-rings. I know, I know, I really should use new ones, but Honda microfiche shows no such beast. If you recall, not long ago I had redone all the gaskets from the head up, so these o-rings have not been in terribly long, so I probably will use them again.


While pondering this stuation and deciding what I should do, I turned my attention to the starter clutch, just for giggles. I had rebuilt this with new springs, rollers, etc., but the bike would usually still not turn over with the starter,even though the motor spun. I turned the rotor over and decided to pull the clutch from its backside. Aha! What is this here?!


The clutch is cracked into two pieces. The bottom crack is obvious in the picture, but there is another one at about nine o'clock, hiding in the shadows of the groove there. That's not good. I called it a day in the garage and came inside to visit eBay, where I found a rotor/clutch asembly for not too much. I laid my money down and will soon have a new starter clutch to mount on Old Faithful.

Next the cylinders, heads and cam case go on.


Road Dog

"Ride Your Own Ride"

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