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Discussion Starter · #1 ·
Putting my '72 CB450 back together and I'm running into a problem with the clutch. I'm not the most knowledgable fellow out there, but I think I have everything set up correctly. This may wind up being over my head, but I figured I'd give things a shot before I give up and take it to the shop. Unfortunately, the bike isn't starting up at the moment (carb problems, I think), so I'm somewhat limited in my ability to troubleshoot this problem.

I have adjusted my cable so that there isn't any play in the lever. When I pull the clutch lever in, it feels nice and firm, like it's actually engaging. Doesn't seem to be binding or anything.

With the bike on the center stand and the clutch lever pulled in, I can't spin the rear wheel. If I'm in neutral, it spins nice and freely, so I know the rear isn't locked up or anything.

If I use the adjuster nut (I have an aftermarket cable) right above the left cover, and really crank it up, the rear wheel will slowly become easier to spin. That makes sense to me, because the more I adjust that nut, the more I'm forcing the clutch lifter rod in, which is slowly engaging the clutch in a permanent way (permanent as in as long as I leave it adjusted that way).

Any ideas why the lever with no play in it fails to let the rear wheel spin, but simulating the lever pull by adjusting the nut slowly but surely must be engaging the clutch because it makes the rear wheel easier and easier to spin the more I crank that nut.

I checked to make sure I have the ball bearing in there, the adjuster / lifter thing seems to be in working order (with the cover off, turning the adjuster clockwise lifts the adjuster), I've adjusted using the clutch adjuster, the nut above the cover, the adjuster at the lever. All to no avail.
 

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Discussion Starter · #2 ·
Been trying to read up on this, and maybe this is expected behavior? Sounds like it is normal for some bikes to be tight when in 1st gear with the clutch in while they're not running.

Hoping maybe that is the case, but since mine isn't starting at the moment, I can't fire it up and try it out.
 

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Let's start with terminology. The clutch is "engaged" when you release the clutch lever and the clutch connects the engine to the transmission. When you pull the clutch lever you "disengage" the clutch. When you pull the clutch lever you only separate the clutch discs by a few thousandths of an inch. Even so, with the bike not running, when you pull the clutch lever you should be able to roll the bike around pretty easily. Your symptoms sound like your bike has been sitting for some time which can make the discs "sticky". I'd get it running and see how it works after a few miles of riding.

It's also possible that your after market cable is stretching. Just adjust the cable per your factory service manual and see how it works.
 

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Discussion Starter · #4 ·
Thanks for the clarification, JT. You're right, it's a project that has sat for quite awhile while life has been attended to. As far as I can tell, everything is adjusted. No slack or play at the lever.

Obviously a perfectly adjusted clutch is pretty worthless on a bike that doesn't run, so my next task is to sort out the carbs. Just noticed the clutch thing while wheeling it around the garage today, so I figured I'd check and see what the experts say.
 

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It's normal for a wet clutch to do that. As long as it goes into gear normally, with the engine running, it's fine. You should have a small amount of free-play in the clutch lever to keep the clutch from slipping and clutch lifter parts from wearing out
 

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FYI, if you disconnect the cable at the lever, and adjust the large adjustment screw (helix) on the front sprocket cover first, then attach and adjust the cable, you will get the most movement of the clutch lifter. Just loosen the small bolt that holds it, turn it CW until you feel the helix press on the lifter, then turn it CCW a small amount.
To see if the clutch is really stuck from sitting, without starting the engine, just squeeze the lever all the way and try cranking with the kick start. The engine should not turn over this way, as the kick start works through the clutch.
 
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