Re: What to look for when buying a CB750

Posted by sgtslag on Aug 05, 2011; 1:13pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/What-to-look-for-when-buying-a-CB750-tp3227766p3228668.html

The C model is more for in-town riding, due to the lower gearing.  If you plan on touring on it, go for the K model.  Check the oil:  look at the color, sniff it to see if it smells burned (you probably know this stuff already, but I prefer to cover the bases, than to miss something...); check the exhaust color upon start-up, to see if it is blue (burning oil), or maybe a little white (normal); check the exhaust pipes carefully, looking for rust (can be replaced, but 4-into-4 is a bit of a challenge to keep); check around the header pipes where they bolt onto the engine -- feel (when it's cold!) for exhaust blowing past the seals; check the condition of the chain (630 on the K, 530 on the C; 630's are more $, and more challenging to locate, but they're heavier, too), to see if it is rusted badly; look at the sprockets, as well, since the book recommends changing all three at the same time (NOT necessary...); check the condition of the spokes on the K; check the condition of the rubber (should be replaced unless they're less than three years old, and they have plenty of tread left; check the front fork tubes for leakage -- oil smeared up/down the sliders, indicates the seals need to be replaced along with the ATF fluid within the tubes.

Some things to realize no matter what used bike you buy:

***Download the Factory Service Manual (FSM) from this site's Home Page!!!***

1)  Plan on changing all fluids (oil and ATF in forks, only), no matter what!

2) Plan on performing a full tune-up:  plugs, adjusting the timing chain tension, possibly adjusting the valves, cleaning and balancing the carbs.

3) Replace all of the light bulbs, including the instrument bulbs (avoids losing them at the most inopportune time...).

4) Possibly needing a new chain, and/or sprockets.

5) New tires -- you only have two!  Your life, literally, depends upon them!  The C will run tubeless; the K will need tubes with the spoked rims -- you can use tubeless tires, no problems, whatsoever, running tubes within them.

6)  Changing the oil and filter; changing the ATF fluid in the forks (check the seals for leaks, replace the seals as needed).

7) Drain the blow-by box, beneath the battery:  catches water, and other gunk, which come out of the engine; can cause engine to run rough, if the bottle fills up, easy to drain, easy to check.

8) Check the health/fluid level of the battery, replace it if necessary.

If you want recommendations on tires, plugs, and other parts, give us a shout.  Cheers!