1975 CB360 Freeze-dried Hell Ride

Sonreir said:
Points bounce gets worse with increased RPMs, not better, so I don't think that's the issue. Have you followed the procedure for tweaking the mixture screws? It would seem to be that you're having issues with the idle circuit in the carbs. Possible something is gummed up or dirty?
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I wanted to make sure the ignition system was working as it should before I moved to the carbs. Gummed up or dirty is definitely a possibility. Opening the float bowls without undoing too much of PJ's work is on the checklist. Ruling out points bounce, should the points fire consistently at a constant size and glow? One thing I notice is they fluctuate in size and intensity and even go dark. I wonder if maybe the backfire is occurring at a miss or low spark at the the points.
 
I wouldn't put too much stock in sparking at the points. Less is usually better, though. Too much and it might mean your condenser is going out. Bad condenser won't usually affect the spark quality, but it will cause your points to wear faster.

If the spark is a concern, check it with a strobe light to ensure it's consistent.
 
Well, I think I figured out what my problem was. I started getting smoke out of the breather tube, which suggested blow by. Compression test suggests piston ring failure. I got 110 on the left and 150 on the right while hot. Dropped some oil in there and we get 180 on left. I don't know if I'm creating the succession of failures or if its just a condition of the bikes history and having sat for several years. When I tore it down for a broken cam chain, I did not replace the rings. They showed good compression (135 both sides cold) in a test before the chain broke. The jugs looked clean and polished. So, I focused on the valves and put it back together. Should I have changed the rings out since I had the head off anyway? Could I have shifted the rings, so they're not at 120 degrees? Do I suffer from some degenerative brain disease that causes me to lose mechanical abilities and sound judgement over time?
 
Setting the rings at 120 degree intervals isn't worth the time it takes to do, I haven't bothered for at least the last 30 yrs
Most likely you damaged a compression ring re-fitting cylinders.
Hopefully the bore isn't damaged
 
trek97 said:
dude, that stinks.
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I'm about to say fuck it and turn this thing into one big experiment and just start doing crazy frankenstein shit to it. It's a rat rod of sorts anyway. I'll bring it to Thaw and maybe it gets tore down and fixed there. Maybe it gets drunk and falls off of a really high bridge. I went ahead and quick shipped some rings from Wiseco. Hopefully the jugs are good.
 
Let's fix it and then throw it off a cliff. No sense in half-measures.
 
deviant said:
I wanted to make sure the ignition system was working as it should before I moved to the carbs. Gummed up or dirty is definitely a possibility. Opening the float bowls without undoing too much of PJ's work is on the checklist. Ruling out points bounce, should the points fire consistently at a constant size and glow? One thing I notice is they fluctuate in size and intensity and even go dark. I wonder if maybe the backfire is occurring at a miss or low spark at the the points.
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Majority of advancer springs are stretched and cause timing to fluctuate at low rpm.
Cut the end off one spring and bend the next coil over to fit on post and tighten things up a bit.
You should still get full advance by about 3,000 rpm instead of 1800~ 2,000 rpm, usually makes bike run a lot better
 
I rechecked the compression several times because something just didn't seem right. I did it cold, then I ran it to operating temp and got 160. I shut it down, let it cool, ran it again for 10 minutes and got 160. Tested it a few more times and continue to get 160. The first time I tested I either didn't have the throttle open, the release valve was depressed or the fitting wasn't seated. Regardless, compression is checking out at least for now. I can't explain why I get white smoke out of the breather. Maybe someone can enlighten me. The motor is definitely getting hot, and the smoke is not coming until riding or running for a while. It's been in the 90's here, so it hot outside too. I'll pull the covers off of the float bowls and pull the slow idle screws to check for debris. I hope some more intelligent brains can help me dial this thing in, because I'm certainly feeling stupid and at a loss.
 
Is it actually smoke or is it steam? If you get it on your hands, does it condense to liquid?
 
It's not an intense amount. Sort of like the second exhale after you take a puff, and don't get all of the smoke out with the first exhale. It actually took me a minute to figure out it was coming out of the breather because it wasn't necessarily obvious at first. It becomes sort of constant though. I first noticed while sitting at a light and looked down at the idle screw. I don't think it's condensation, but I haven't checked either.
 
deviant said:
It's not an intense amount. Sort of like the second exhale after you take a puff, and don't get all of the smoke out with the first exhale. It actually took me a minute to figure out it was coming out of the breather because it wasn't necessarily obvious at first. It becomes sort of constant though. I first noticed while sitting at a light and looked down at the idle screw. I don't think it's condensation, but I haven't checked either.
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my sl350 did that for 12,000 miles, and it used a bit of oil
i rode the hell out of it
get it running good and ride it
 
Damned if you do....Damned if you don't. If it is running ok and not a lot of smoke....I say Don't and keep an eye on it. It's not confidence inspiring but on the other hand you've had worse ::)
 
After my rebuild, mine was doing this for about 20 miles. Took a while for all the moisture in the air to get cooked out of the engine.
 
I put a bunch of miles of Kentucky twisties on the CB at Spring Thaw. Trek helped me dial in the carbs and now the bike runs really, really well. PJ's carbs are brilliant! Save for the left points wire grounding on the points cover 4 times, it was a good three days for the 360. A little die grinding to the bottom of the cover, some fancy orange electrical tape, and it was all smiles from there. One thing to note: It has been pointed out that I need to be running with resistor type coil plugs.
 
deviant said:
I put a bunch of miles of Kentucky twisties on the CB at Spring Thaw. Trek helped me dial in the carbs and now the bike runs really, really well. PJ's carbs are brilliant! Save for the left points wire grounding on the points cover 4 times, it was a good three days for the 360. A little die grinding to the bottom of the cover, some fancy orange electrical tape, and it was all smiles from there. One thing to note: It has been pointed out that I need to be running with resistor type coil plugs.
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Wooh! Good news man. Gonna start riding it to school?
 
plagrone said:
Wooh! Good news man. Gonna start riding it to school?
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Yessir! Every day. Except, I have to wait until a new ignition switch gets here. My dumb ass somehow lost the key between here and Kentucky. Haha!
 
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