Topic: Bought a 72 CB750 K2, running but carb leaks, front-brake, iffy clutch

[edwardmorris]

So I gave it a try again today, with a full charge on the battery and the choke pulled. This time I may have even got it to start with the kickstarter, but the only catch is that with either of them, kick or electric, the bike won't start unless I give some throttle even with the choke open all the way. I let it run for about a minute or two, then shut off the choke and it died within seconds. Started right back up with the choke open, this time I shut the choke while giving it full throttle, and it stayed on with surprisingly low RPM at full throttle. Let it warm up some more, then I dared shifting into first with the clutch pulled in all the way and CRAAAAAAAAAANKKK. Didn't turn off nor did it shift, but sure scared me lifeless. After that, I left it alone as it was heating up bad. So I guess next thing to tackle is the clutch? I recall though, that on the day of purchase, the bike started with the electric starter without giving throttle, and just shut off the moment it shifted into first.

[Stev-o]

Yes, adjust clutch.  May be a good idea to replace the cable first, though, a very simple task.

[Nic]

My 750 needs just a little throttle with full choke on or "closed" not open, sorry, couldn't resist. The choke is open when off, anyway, I can't just push the choke off after a minute, I need to just open it a tad from full on usually then I ride it a couple of Ks with half choke and not a lot of throttle before it likes the choke full off. You'll know when it's warmed up proper as the throttle will start acting the way it should with the choke all the way off. You'll get the hang of it.

[edwardmorris]

Grr, REALLY getting aggrevated by those pesky air bubbles in the line. I cut them short but its still happening, getting sick of flooding them out everytime. Whats making bubbles?

[754]

Trust me....Dont look at the bubbles.  Put black line on if you cant stand to see them. The bubbles are not hurting anything.

[edwardmorris]

Trust me....Dont look at the bubbles.  Put black line on if you cant stand to see them. The bubbles are not hurting anything.

It won't start when there are bubbles in the line and I can tell that the gas is not moving at all. When I flush them out and start it, all works well, then when I shut it off and come back within the hour, air gaps and zero luck starting it without flushing them again.

[Powderman]

Got the master cylinder rehabbed in Tuscan Black Matte. Hopefully Rafi has a before pic to post as I forgot to take one.
Here it is stripped and blasted and ready to coat:



And completed:

[Stev-o]

Hey Mo....you get the brakes working yet?!

[edwardmorris]

Hey Mo....you get the brakes working yet?!

lol very funny!

[Stev-o]

Hey Mo....you get the brakes working yet?!

lol very funny!

Ha!

It's fun going back and reading your old build threads and see how far you've come and how much you have learned. 

[edwardmorris]

Hey Mo....you get the brakes working yet?!

lol very funny!

Ha!

It's fun going back and reading your old build threads and see how far you've come and how much you have learned.

haha, yea its embarrassing. When I was tearing down the engine, I remember being constantly scared and kept running back and posting something just to get some validation that I didn't screw it up It took me days to get it done. Thankfully everybody here had the patience to put up with all that, great great community! When time came for the K3 tear down, it took me just hours to be done with it and back inside, quite the difference once you know what you're doing