Took out the ct3 for a shakedown run and shook off one of the headlamp bolts.

After warm up I had several instances of being in neutral when I thought I was in first and rolling on the throttle and slowly letting out the clutch left me in the middle of an intersection.   Would removing the rubber clutch rings help?

Tried for an extended full throttle run. After a couple of minutes I experienced several stumbles or cut-outs. they were not abrupt and felt like I was not getting enough fuel.   I let off the throttle and only experienced the stumble again when approaching top speed after 10-15 seconds.  Phone app indicates that my top speed was 63 mph.  

Stopped for lunch. I had trouble restarting. It took 5-6 kicks. Perhaps the plug was fouled with oil.  

Got home and saw the right half of the crankcase was splattered with oil; some black and some blue. I recently slightly over filled the oil tank reservoir with Yamalube 2S. There also seemed like a lot of oil was coming out of the exhaust gasket/clamp.   I looked in side the oil pump area which was relatively clean

  

I had recently adjusted the oil pump and bled it.

Here is a photo of the spark plug from yesterday which had been installed and used from before the oil pump adjustment.

 

Any thoughts or words of wisdom?


pertinent background:

In the last year:
installed new friction disks, left original plates and rubber things
filled with Yamalube Trans Oil Plus 20-40
installed new oiled air filter
replaced crank seals with redi-sleeve over magneto side of shaft with permatex motoseal to mitigate pitting near oil seal surface
adjusted the timing to start points opening at 1.8mm BTDC
replaced cylinder base and head gaskets, tightened head bolts to 18 ft/lbs in four ft/lb increments in criss cross pattern
replaced intake manifold and reed valve gaskets
replaced exhaust gaskets
installed new petcock
B8ES spark plug
rebuilt/cleaned carb using original spec jets and slide
have not burned out the carbon in exhaust

 

Maybe you're just burning out old transmission oil that was in the crankcase?

I left the rubber rings out of my clutch and I haven't had any problems shifting it, but I can't imagine leaving them in would cause a problem with that. Does it seem to go firmly into first gear when you hit it? I'm not exactly sure what you're describing, is it popping out of first gear? If it was in neutral when you let out the clutch, you would just stay where you were.

Just yesterday I got done trying to seal the exhaust pipe to that flange, I used orange high temp RTV. Put some into the groove and set the exhaust in, then pulled the exhaust out and filled it up again and put the exhaust back, then "caulked" it around the flange and put a heat gun under it for a while. We'll see how long it lasts.

I downshift when approaching a red light.  When I come to a stop, I put it in neutral. When I am preparing to go in anticipation of the green light, I shift down a bunch of times to make sure I'm in first. The neutral light is off and I think I'm in first but if acts like I'm still in neutral.   I don't feel or hear anything to suggest that it's popping out of first. It only occurs after the bike has been fully warmed up.  

One thing I noticed about this bike is that I don't feel or hear the thunking that I've experienced from other bikes when shifting from neutral into first.

One thing I didn't do is torque the exhaust bolts to a specific measurement. 

I just remembered that I though it unusual for the amount of oil around the spark plug hole:

 
 

As I approach a stoplight I usually tap the shift lever down numerous times to make sure it's in first, before I go up to neutral, but once I'm ready to take off I just push down once. Maybe by tapping numerous times from neutral you're causing it to shift slightly out of first or something? I'm thinking maybe if you're pounding on the shift lever numerous times, it's jumping back close to neutral, but not far enough to engage the neutral light?

Your exhaust pipe is leaking from the flange. Not from where the flange is mounted to the cylinder head. The pipe is only held on with springs, and normally there's a string packing in there, but it's probably gone. That's why I tried to seal mine up yesterday with orange RTV. Seemed like I was getting a lot of noise out of the front of the engine, and it did quiet it down a bit.

Thanks, I will check the string packing.  It might have fallen out when I took the jug off to replace the base gasket.

If it's the original gasket, it's probably shot or gone. I used a long needle to feel around inside there and there was nothing inside mine. I almost ordered another one, then I tried this high temp orange RTV solution, and so far it's holding pretty well. I've also read elsewhere on this forum that some people have taken string and coated it with the RTV, let it dry, then packed it in.

 
 

Looks like it might be coming from both gasket & packing area so replace both plus rtv the string as Tom P says. If its not easily selecting first i wonder it the eccentric gear change centralizing screw needs tweaking a little. Not easy to get at though. Can you easily hook second from neutral & start off. Test for the screw setting is best when in gear--make that 3rd gear or test will confuse--& feel the free spring loaded movement up & down to hook the next pin. Movement should be similar both ways. But if there's a lot of movement upwards to hook 4th gear & then [from a resting lever] if its missing or touching the down change pin maybe its not hooking it when running & your foot is touching the lever. Confused--i am lol.

yes, thoroughly confused.  first time I've heard about an eccentric gear change centralizing screw. I will read up on it.   thanks though.

Both the packing and gasket were new as of April 2021 but I was in a mad rush to get things back together and might have fudged something.

 

Number 4. it's an off center screw. Bit hard to explain. It sets the claw arm equal over the drum pins. If was ok befoe it should be ok now though & mostly oinly changes is someone's dumped the bike hard on a rock etc & forced ther gear change beyond limits by bending the wobbly screw veven more-so i guess. Never seen one break off though. Realy its ascrew to make up for slight machining discrepencies possibly.

The string gasket was mostly gone, kind of disintegrated. Thanks ! I am surprised it had less 100 miles on it.


While the pipe was off I took some photos. I was expecting more gunk inside. Does this look right?

The string gasket was mostly gone, kind of disintegrated. Thanks ! I am surprised it had less 100 miles on it.


Since the pipe was already off I took some photos. I was expecting more gunk inside. Does this look right?