Topic: CB450K7 running on one cylinder

[Johnny5]

Hey everyone,

I have a 74 CB450 and am working on getting it in running order. Did all the regular maintenance per the shop manual, so new spark plugs, adjusted the cam chain, valves, timing, and carbs cleaned. Verified spark on both cylinders and was timed with my auto timing light. What I'm getting right now is a strong running left cylinder and a poor/barely running right. Spark plug color on the left is golden brown and the right is wet with gas. So it's sparking but gas is still flooding in. I do recall the exhaust valve adjuster feeling tight even with the lock nut loosened when I set the valve clearance. If this valve is giving me fits for whatever reason, would this cause my symptoms? Is it possible for that valve adjusting rod to be completely turned the wrong way but still be able to set the valve clearance? Im a bit perplexed.

Bike is running super strong on just one cylinder, so it's promising what she'll run like after the right side is running.

[tbpmusic]

The cam follower shaft has a little notch mark on the end - this mark should point away from the spark plug.

[Johnny5]

Here's a couple pictures of the right side. The inlet side looks like there's a super faint round punch mark facing outward. I marked it with the arrow. The exhaust side, there's no mark on the outside, but the inside is all knackered so I'm assuming the punch mark is probably there, so this would be facing the wrong way. So from here, do I put the motor at TDC on the right side and simple turn that follower to face the correct way?

Inlet


Exhaust

[MoMo]

If you set the valves with the motor at TDC for the right cylinder and used a .002 feeler gauge you could not have made a mistake....Larry


Have you done a compression and/or leak down test?

[Johnny5]

If you set the valves with the motor at TDC for the right cylinder and used a .002 feeler gauge you could not have made a mistake....Larry


Have you done a compression and/or leak down test?

Havent done a compression test yet. Also from what I've found online is that the punch marks are supposed to be face away from the spark plug and I really can't tell from the old adjustment ends. When I was adjusting the valves, those followers can be turned all the way around, so it's possible there's a mistake if the marks are pointed in the wrong direction. Just having a tough time seeing the marks. Usually they are round punch marks but these if they are there, look more like a small line.

[MoMo]

Here is a clean photo.   As mentioned before setting should be correct if procedure was followed

[Johnny5]

Here is a clean photo.   As mentioned before setting should be correct if procedure was followed

Yeah, the marks are little lines. I could barely see them on my bike because it's pretty knarled up. But it looks like it's in the correct position.


I figured out the issue. It was indeed a carb problem. At times gas was flooding into the right side, at times no gas so it wasn't consistent, but after pulling the float bowl, there was the issue. A tang was interfering with the float being able to do its job. It's now firing strong on both cylinders. Feels good!

[MoMo]

 good to go