cb750 engine rebuild

[350rattle]

First post for me but I have lurked for a while. I am close to getting a ’73 CB750 with 25K miles on it. The bike runs and has good compression. I was planning on doing a top end engine rebuild, lap valves, carb clean and rebuild, and brake overhaul.

A few questions: When I get in there, what am I looking for that would make it necessary to delve into the bottom of the engine? How much more involved does this become then? Any other maintenance items that would be logical to do with a bike with this many miles while I am at it?

Just a start, more questions to come. Thanks in advance.

 

[Rocan]

when you drain oil metal shavings means you need to dwelve into the bottom end.
otherwise not much reason if compression is good and shes shifting fine. the hondas really do live and die by their top end.

 

[crazypj]

First get a good service manual or three (Haynes, Clymer, Honda)
If it's been beat on the primary chains wear uneven and may need replacing.
I haven't done one for a long time, engine weighs 212lbs, not sure I could lift one out of frame now

 

[rockcitycafe]

opened quite a few 750 bottom ends, never found one that didn't have uneven primary chains... bad design imo, shoulda been hyvo

 

[skyshadow]

Treads jacking in efforts to keep another thread from being creating superflorously... Any pointers on removing the jugs on a cb750 DOHC?

 

[carnivorous chicken]

First post for me but I have lurked for a while. I am close to getting a ’73 CB750 with 25K miles on it. The bike runs and has good compression. I was planning on doing a top end engine rebuild, lap valves, carb clean and rebuild, and brake overhaul.

A few questions: When I get in there, what am I looking for that would make it necessary to delve into the bottom of the engine? How much more involved does this become then? Any other maintenance items that would be logical to do with a bike with this many miles while I am at it?

Just a start, more questions to come. Thanks in advance.

Just out of curiosity, if the bike runs and has good compression, why are you rebuilding the top end? If it runs but not well, have you tried standard tune up procedures to see if you can get it running better (adjust valves, timing, new plugs, points and condensers, check air filter, sync carbs, etc.)?