Topic: Suggested preventive maintenance batting order CB750 K3

[Sigop]

Searched here for this subject and may not have exhausted what is on here, but will ask opinions.
Bought and have an original 750 K3 with no customization and 37K miles.  I have ridden it on and off for several years, and currently back running well.  (Well at perhaps 80% since I have yet to vacuum tune and will be ordering gauge for that.)

If it ain't broken don't fix it is running through my head. I only have one bike and work full time so I would hate to take it offline for too long a time (winter is short here in NC) On a bike that's 44 years old things are wearing and subject to giving up.  I'm not a great mechanic--make that very limited. BUT, if I should, what should I be starting to explore/check for/replace in progressive order of importance. For instance, I'm thinking tires, brakes and chain first. But brakes SEEM to work fine when I need them. New rubber 3K miles.

Anyway, any suggestions on if I should start a pm and if so, on what to start.  I'd appreciate any thoughts you folks have. Thanks in advance.

Note: Have been exploring cleaning/replacing chain/sprockets as an initial starting item. Hate to think what I have forgotten over 40+ years but think it is the second chain. Or not?

[Chachi]

I think the best basic thing to start with is the standard 3k tuneup - see attached pics. Should be plenty of links in here for the punch list and it's the manuals, etc. And if you haven't done it, you could drop oil pan and clean the screen and drain/refill fork oil. Check head bearings and swing arm. The other safety concerns need to be identified by you and addressed if needed - tires, brakes, chain, etc. But they are also all listed in the maintenance intervals in manuals.

-Oil and filter change
-Spark plugs check/replace
-Check points and timing
-Check valve tappet clearance
-Cam chain tension adjust
-Clean or replace air filter
-Check carbs
-Check throttle cables
-Fuel filter screen clean
-Fuel lines check
-Clutch operation check
-Brake fluid level check
-Brake shoes/pads check
-Brake control linkage check
-Check rims and spokes
-Check front and rear suspension
-Check swing arm

[SOHC4 Cafe Racer Fan]

Excellent advice.

[seanbarney41]

+2 on the 3k tune-up.  I have not found vacuum sync to make much difference on a already good running bike.  Oil change, oil change, oil change! And these engines are quite durable.  I end up replacing steering head bearings and fork seals on nearly every old bike I have had.  Best preventative maintenance is to ride often and fix stuff when it breaks.  And remember, cleaning is checking.

[Stev-o]

How old are the tires?  [date of manufacture is on the sidewall]

If over 7 years, order a new set.

[Sigop]

Thanks all.  Have performed most of the 3000, including gutting and cleaning carbs with wires, clearners and air.  Disassembled and replaced rings, gasket and filter on petcock, cleaned points and reset timing, though I think that is still off a little.  Have played with  air fuel mix screw but don't feel like I quite have that right yet.  Know the valve tappets should be done first, so had to order bent tip feeler gauge and then will restart entire sequence again.  Only about 3k miles on oil and still clear so good for now. Adjusted cam chain. New plugs and snipped end of plug wires and rescrewed the caps. Air box disassembled, cleaned, new filter and gasket so check. New airbox to carb rubbers and wintergreened carb to engine rubbers. All new fuel lines from tank and at carbs. Fuel tank some small rust inside way down in sides so OK for now. Throttle cable slick and spring responsive--good snap back.

Steering head bearings and fork seals are beyond my skills and tools, I'm afraid and certainly do not trust a shop with any work on this bike. Can drop pan and clean under there, and could also drain front fork oil, as well as check out master cylinder.  Good tip on tires--will check for date.

Thanks all.  Will update in future in "what I did to my bike today."
Safe trails.

[seanbarney41]

Sigop, just a couple things, oil change interval is every 1500 miles, motor oil lubeing the gearbox wears it out fast, steering head bearings and fork seals are easier and require less tools than rings

[Johnie]

Every 750 I do gets 2 new front wheel bearings, 2 new rear wheel bearings and 1 new carrier bearing. Back in the day sealed were not used so get yourself some new sealed bearings. Every one I remove shows dry bearings and would hate to have one go out on the highway. Again, not hard to do with the assistance of the guys here and the Hondaman manual. Cost of the bearings is about $50 and all you need is a hammer and long punch. If the OEM steering bearings are not notchy I clean and repack. I will guarantee yours are really dry. Again, not a bad job with the help of the guys here.

[Sigop]

Seanbarney41, I hear ya on the oil and will do. 
Johnie, you're goading me into something over my head, but if bad due to age, I have no choice.  When I start that I know I'll need help.  Will the Clymer's work for me?

Thanks guys.

[Johnie]

A Honda service manual is better than the Clymer, but the Clymer is better than nothing. Member Hondaman has a must get book on these bikes.

[70CB750]

Would not hurt checking swingarm for side to side play. If excessive. get new bushings for the arm.

 Also take the arm out, clean it and repack with fresh grease. I do it everytime i change rear tire.

[Sigop]

70cb750.  Thank you.