Topic: CB 750F Super Sport Question

[Falcon75]

Just recently picked this bike up and not sure how you can tell if the head gasket is gone. The bike was sitting for awhile and the seller put some seafoam in the oil as well as the gas tank to loosen things up. I have changed the oil and it smell of this seafoam. I will keep an eye open on the oil reservoir to see if will be filling up with gas and oil.

Bike is really loud when idling, sounds like the cam change needs adjusting, will have to look at that.  Does seem to be down on power as well, not sure if its running on all cylinders? Well I have a lot to learn when it comes to these bikes. And my learning curve will be steep ha ha.

CHeers Bruce.

[Kickstart]

Congratulations on your new bike...

I wouldn't worry about the head gasket just yet.  I believe most of these bikes generated a slight head gasket oil leak.  I know all of mine have it.

I would do a compression test just to see what you have though. 
If you're not sure if one of the cylinders is firing... after the bike warms up for a minute (or while it's warming up) spit on your fingers and quickly touch the headers.  If one or more doesn't sizzle when you touch it then it's missing on that cylinder (or at least missing more than the others)

Do the basic stuff first (timing, cam chain adjustment, valve adjustment, spark plugs, air filter, oil change) and see what you've got before you start to take anything apart.

Good luck.... and post a picture if you get a chance.

- Chris

[ChuckG750f1]

The cam chain makes noise even when it's adjusted.  But, carbs out of sync and/or cylinders not firing will make things worse.  Also, the clutch basket is probably adding to the noise.  Pull in the clutch and see if the noise diminishes.  Kickstart's advice is the place to start.  Good luck.

[TrueSpin]

Once you've had a look at your timing and checked whether all pipes are hot, please provide a little more detail about the bike so we can help diagnose further (if you need it, that is).
Your forum name says F1, so I assume it's a '76, but you know what they say about assuming.

[Jerry Rxman Griffin aka MuthaF'er]

Bruce,

Adjusting the cam chain tensioner is a piece of cake so get that out of the way. One thing you might consider is "helping" the plunger a little by inserting an allen wrench, etc in the open end and pushing slightly while the adjusting bolt is loose and during retightening. The adjuster bolt can be tightened too much creating a divot in the shaft and the spring may not be enough to push it inwards.

As mentioned, the clutch can/will create a rattle. If it goes away when you pull in the lever then that's at least part of the noise.

As mentioned, carbs out of sync will cause rattle also.

Then there is stretched primary chains &/or a bad primary chain tensioner. That's a serious issue as far as repair goes - remove engine and take it apart. That's a rattle that you'll most likely live with until you HAVE to get into your engine.

Just be sure you go through all the tune up steps first.