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'76 cb360 trouble. again.

2175 Views 14 Replies 6 Participants Last post by  tbpmusic
Ok. I had the bike running pretty well for a while, it wasn't perfect but I was getting closer. Then it started fouling the right cylinder plug and causing the right side to quit running. I would pull the plug, clean it up and put it back in and all was well for a few miles. I tried adjusting the air mixture screw (after syncing the carbs as best I could) and it didn't seem to make any difference (I know the bike has to be warmed up to make carb adjustments). All the while the left cylinder has been running great, plug looks good and all.

Now a more troublesome issue. I have been trying to figure this out, mostly by trial and error, which means I get the bike running and go for a ride, bring it back and make adjustments. I pulled the carbs and cleaned them, again. Well, it starts right up on both cylinders and I can rev it fine, I pull out and it spits and sputters in first, pulls well in second and then the right cylinder dies. Turn around and limp it back on the left cylinder and when I park it and shut it off, I get real black oil coming out of the header to muffler joint in the right side exhaust! What? I did seal the header to muffler joint as was suggested here when I got the new mufflers, but obviously its not sealed anymore. So I can get it running on both cylinders again without much problem, but then I get a lot of smoke out of the right side because there's all this oil in there.

Now, I'm just assuming its oil that's in the exhaust. I had to add a little oil today but I really haven't been running it that much. I checked the compression again today, 150 psi in the right, 152 in the left. The points are spot on, both sides, as are the valves. I know the compression is right on the line for a top end job, but I'm trying to avoid that if possible.

I honestly don't know where to start. Help.

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Ben, Regardless of the PSI reading, you are "pumping oil" out the cylinder and into the exhaust. It is possible that that same oil actually increases the PSI reading (deceptively) allowing you to believe it is better than it actually is (would be) dry, and your rings are REALLY bad........

However, fuel in the oil sump (unburnt by-pass or leaked in through bad petcock/ bad needle and seats, or bad float levels) can raise the oil level to the point this symptom can occur...... SMELL THE OIL.... IF there's ANY gas smell, don't run the engine... Find out how the fuel is getting in, and fix it , then change oil.....

Let us know.....
That oil is getting into the cylinders somehow...You just need to figure out how..... Bad head gasket leaking in?..... Worn valve guides?...... "Stuck" oil ring on that piston?...
Several possibilities that could still show semi-decent compression readings.....

Unfortunately, the cure for any of them is tear-down and check......Unless you can think of a different possible cause......
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