Common problems: 77 cb750k

[keyconversations]

I just made a purchase on a 77 cb 750k W/ 46k.  turns, but not running with registration dating 01....  I have built many kz650's and welcome this new challange...   Not really interested in splitting the crank case what do I need to pay attention to as I restore this old girl??  My worry is that this motor will have the same poor quality as the early 80's cb 750k that I have experienced through my friends purchase bringing it back to life.   Somebody install confidence in my purchase and tell me that with good work this motor will run in perfect harmony.. :)

[Peterwh]

Welcome to the forum.  You will find what you are looking for here.  I guess you are in the UK, correct?  With good work this motor will run in perfect harmony!

[Piute]

    Welcome   
  After all the read ups I've red I believe So also...Piute...

[Re-run]

Key, the sohc had a very strong case. If the motor turns over and has decent compression, say at least 110 psi, then you should be good there.
Main things are to get the carbs cleaned very well. The idle jets are push in but if you wrap a little rubber or even cloth around them and grab and twist while pulling, they pop out and you can clean them.
The accel pump will require attention too.

After that, standard tuning steps and barring something buggered by the last owner, she should fire up.

[TOOLS1]

Welcome to the forum. Unlike the 79 up DOHC bikes. The 69-78 SOHC bikes are pretty much bullet proof. 46K really is not enough miles to warrant a rebuild. The only real trouble spot with these bikes though is the 40 year old electrical wiring. And I do agree with Re-run about the carbs. However I remove the pilot jets by tapping then with a 4-40 tap, and a puller made with a short piece of metal break line tubing, and a 4-40 screw. You only need to tap it about 3/8 of an inch. Sometimes the the pilot jet will come out while tapping it. However if it does not, just slide the piece of break line tubing (about an 1 1/2 inch long down over the pilot jet. Thread a nut up on the screw, and then screw the screw into the pilot jet. Then tighten the nut against the break line tube, and the jet will pop right out. When installing it back in, just tap it in with the handle of a screw driver. Also if, you drill out the pilot jet to .45mm it will make cold starting a lot easier.
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[Lucky 1]

The 1977-78 CB750K models had many improvements over all the rest of the older models.
About 21 improvements.

Longest swing arm.
Better cam chain.
Wider cam chain galley.
Bigger valves.
Higher 4th and 5th gear ratios.
9.2:1 compression.
Accelerator pump on the carbs.
Larger cylinder head studs.
Better oil drains.
Better valve cover breathing ports.
Bigger clutch basket and stronger springs.
More fins on the engine and oil pan.
Etc.,.

You can look up the rest.

[warhawk]

may I ask on how can you know the manufactured date on a Honda CB750e...am interested in restoring the above motorcycle

[TOOLS1]

"CB750E" is the start of the engine number. If I had the rest of the number I could tell you the year it was manufactured.
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