1982 CB750c Custom

[myTUNES]

Thanks for creating such a great forum for CB750’s. I will continually post the progress of my refreshment of this beautiful 1982 CB750c Custom. I recently purchased this bike off of a Craigslist ad for 900 dollars. I know it is a bit much, but the bike ran perfectly after being jumped off and tapping the starter solenoid (gentle coax). This included a spare tank (little rust inside), fiberglass saddlebag with a built in seat, two sets of crash bars, two grab bars, another set of carburetors, and a box of miscellaneous things: tail light, blinkers, and emblems. This will be my first refreshment of any motorcycle. I have never owned one before, but recently caught an amazement and attraction of older Honda CB’s. After a little research of the forums and Google searches, I changed the oil and oil filter, changed the starter solenoid, and changed the battery. Currently the battery is on a slow charge of 12volt 2amp. I am going to leave it charging over night and start him up first thing tomorrow morning. I used Texaco Havoline 10w-40 and went with a cheap FRAM filter. I checked to make sure the clutch was engaging by rolling the back wheel in first gear with the clutch pulled. The clutch works perfectly. I also attempted to bleed the front brakes, but there wasn’t any pressure against the lever at any point of the bleed.  Tomorrow I will pull the front caliper and see if the caliper piston is seized, or if I will need to replace the master cylinder. My guess is the master cylinder is bad. The seat is in perfect shape without any rips or tears; I was in such a hurry to pull the parts off and get them replaced I forgot to take pictures before I began working on him. I look forward to reading more about your bikes/builds; I know I will learn a lot from your posts and all help and information is gratefully appreciated.

[Hoosier Daddy]

Nice score! Especially with all the spare bits-n-pieces.
First thing I noticed was

myTUNES wrote

I used Texaco Havoline 10w-40

Drain it back out and pick up some motorcycle oil
Regular automotive oil has friction reducing additives that are BAD for the clutch plates in a motorcycle. You can get away with straight non-detergent 30w as a flush the first time you start it. You can even run Shell Rotella-T diesel oil, but don't use regular automotive lubricants.

Also at 2 amps you may want to let the battery charge a bit longer than overnight. 24 hours minimum is a safe bet.
Sorry to piss in your Cheerios all ready, just want you to get started off on the right foot.
Welcome to the forum!

[Piute]

   HECK
  That may be why my clutch is slipping ,been running 5-30 Valvaleeen past monthGetting Cycle stuff this morn.May just see how bad Head leak will get with the Rontel Syn.That I HAVE but haven't used cause worried about making leak worse.What the heck  SLIP Can't get worse I hope it will not.

                                                    Sorry think thoughs early 80's "C" are great

[Hoosier Daddy]

Piute wrote

HECK
  That may be why my clutch is slipping ,been running 5-30 Valvaleeen past month 

That'll definately do it Piute!  

[Piute]

                                      Much Appreciated
                                                           HOOTTER DADDY

[myTUNES]

Thanks for the advice Hoosier. I guess my uncle can use a gallon of 10w-40 Havoline. I will leave the battery on charge until 3pm or so. That should be 24 hrs.

[myTUNES]

So after my oil change debacle; I went out and tried to find some quarts of Mobil 1 racing 4T 10w-40. I seemed to have no luck at the local parts stores. I will have to wait until Monday to go to a motorcycle parts store just inside the 285 loop; a few miles from my house. I figured while I was in the parts store I could pick up some starter fluid and a few bundles of steal wool. It began raining as I arrived home so I will wait for the start up until I get the oil changed. I was able to pull both front brake calipers today. Once I pulled the pins and took out the pads, I removed the rubber sleeve around the caliper piston. Upon inspection I found large amounts of rust and what I can guess is brake fluid and plain ole crud around the piston. I removed it the best I could with steel wool, doused them in wd40, and tightened C clamps to loosen them. Those will soak over night and I’ll check on them later tonight with a little more wd40 love.

[Hoosier Daddy]

Heh heh "HOOTTER DADDY "

Maybe this would be easier for you to find...



Or this...

[sgtslag]

Motorcycle oils tend to be high priced (check the SAE rating, to make sure it is the proper type, for your engine, as many M/C oils are formulated to an older standard...  SF, SG, etc. -- current is SM).  Shell Rotella T (conventional; SM for cars, won't void any factory's warranty)/T6 (synthetic; SM for cars, won't void any factory's warranty) is available at Wal-Mart, and just about everywhere else.  The Shell is 'diesel' (rated SM for cars, too!), no friction modifiers (no energy star symbol), is 10W-40 (conv.)/5W-40 (synth.), M/C rated by JASO, higher in detergent levels, and runs ~$13/gallon conv., ~$22/gallon for synth. (at Wal-Mart, more at other places).

The T6 is very popular amongst various motorcyclists -- do a search on Shell T6 and motorcycles, to see what I mean.  It is great oil.  With the T6, I have switched everything over:  car, truck, motorcycle, lawn mowers, snowblower, and a 1965 Sears & Roebuck Air Compressor (would not turn over in the Winter, with straight 30W, needed it to run -- put in the T6, and she spun over with no issues, aired up the tire I needed, and life continues to this day, without issue).  With the T6, I can stock one type of oil, and be good to go with any engine.  Makes my life a lot simpler.  YMMV.  Cheers!

[TOOLS1]

Texaco Havoline 10W-40 is a perfect oil for your bike. I have used it in more bikes then most of the members here combined have owned, and never had a problem. If an oil has the a fore mentioned "friction modifiers" it will be listed on the label, and should be avoided.
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[myTUNES]

After the oil, solenoid, and battery change he starts without any problems. I initially had to spray a little bit of starter fluid to get him to ignite and idle for a few seconds. Scratch my head once and put a little fuel in the empty gas tank, haha he runs constantly at idle with no choke and will restart without hesitation. Glad I didn’t run any trash from the tank *fingers crossed 4 starts shouldn’t do that*. Its’ current idle RPM is about 900 cold and 1100 warm. I couldn’t be happier with the bike. It did have a small clank coming from the top end on the left side, but after about 30 minutes of idle, to condition the seals, it has quieted a lot. I think I will give him a good bath and try to clean the engine from any grease and grim. Do ya’ll have any good tips or cleaners that you love?? I will be posting a video tonight for ya’ll to enjoy, and I will be cleaning the spare set of carburetors I have for fun, practice, and a learning experience. I heard a rumor of soaking the aluminum in Pine Sol. Do you have any thoughts on this?

[Piute]

    I would not suggest a high power car pressure wash UNLESS  you know what your doing & not in a hurry,HURRY causes problems( we all no this),
      I us foam engine spray(keep away from chain/area) Then just yo regular garden hose to rinse off,The high pressure will put water into all & any area that has a bad gasket(if not bad can make bad)..Points , "O"rings, unsealed(shrink tube)electrical connections,This is one time that I would say PLEASE don't get in a hurry and use a high pressure wash,BUT GO AHEAD cause most will

[myTUNES]

No worries Piute, I only have a car wash bucket and a garden hose. I made sure to keep all the coverings I.E. side covers and seat, on the bike to refrain from getting water into the air intake and battery compartment. I didn’t even spray the hose too hard near that area, and the ignition fuse on top of the handle bars. I had a can of half used engine degreaser so after the wash I covered the engine in the spray degreaser, and I’m waiting 30 minutes or so to wash it off. I’m kind of worried about the spark plugs getting water near them, but I put a few scrapes of rags around them.  I figure I’ll take the seat and side covers back off and make sure everything is still dry in there. I have a sample of car wax from a car show; maybe 2 years old. I’m going to try and get “some” shine back to this old tank. lol

[myTUNES]

If ya’ll would? Please help me identify the ticking sound coming from the top of my motor. It has since quieted a lot from this video, but I would like to know if there might be any underlying problems that anyone can foresee. Thanks again ya’ll; I love my CB750c.

http://www.youtube.com/watch?v=LLmhKrds-hc&list=HL1357265167

[myTUNES]

Waiting for paint; any ideas? I’m leaning towards British racing green. Well, I’m really excited about how well it runs and pulls through the gears. It is still a little sluggish getting to 5k RPM, but after it reaches that it pulls through the higher RPM’s really well. I did find a tear in carburetor number 4’s insulator. I think I should just repair it with some E6000. I’m sure it still needs a carburetor sync as well. Next projects on my to do list is: paint the wheels and mount my new tires, check valve clearance, check the charging system with my new analog multimeter, move the toggle switch to the inside bottom of my head light, put my chain guard back on, put my painted emblems back on, cut down my exhaust, paint and wrap my exhaust, but for now I ride.











Video After Carburetor Rebuild:

http://www.youtube.com/watch?v=Cyvwr2-mU6s

[Piute]

                                 Nothing better then "Fresh" meat

                                           I like a lot of bite

[myTUNES]

Just don't burn them..

[myTUNES]

I will get to the bottom of this problem. The motor revs through the RPM’s, but it sputters or jumps  1k to 3k without much power, and once it reaches above 3k its power is greatly diminished compared to how I remember it being before, but it doesn’t sputter, and pulls without jumping or losing power. I rode it around town maybe a mile to the parts store, then to the grocery store. At the grocery store I looked at the header pipes. With a wet finger the 2-3 pipes would sear the moisture off my finger, where as the 1-4 would not. This is the only thing that would lead me to believe there is another problem than the insulators, but I will be replacing those as well. Tomorrow I will check the spark for all 4 plugs during low and high RPM’s along with the charging system.



Any help for this poor soul TOOLS1 ?

I currently have new NGK spark plugs in, and I checked the plug wires for spark with a grounded screw driver. All of them make spark, but I feel I am running on alternate cylinders during load, 1-4 during low RPM and 2-3 under higher RPM. I will test this theory tomorrow with the spark plug gap tester.

[myTUNES]

Well, after checking my timing last week. I noticed that my timing light wasn’t flashing at RPM’s over 3k. SUSPICIOUS . I couldn’t rev the motor up to high RPM’s with the wire unplugged and plugged into the spark plug gap tester, so it was almost useless, not to mention the plugs wires are to small to fit the tester. Some ideas just never pan out.

I then tested the spark units (igniters) from the side of the battery box, coupler A and B both read 12V, followed by the pulser. Hmmm 0 OHMS resistance.

So, I finally got my pulser in the mail yesterday from CT. The seller told me about the three foot of snow they received over the week prior, and shipping would be delayed. Luckily, it was only one day delayed, and I got it on the bike first thing this morning. It feels so much better. It pulls through all the gears, as every cylinder is firing for the first time since I disassembled it for paint. I forgot how fast this bike is, and the new spark plugs just make a huge difference as well. Next to come are CBR900rr coils and new wires. I think I am going to retard the ignition slightly also, I think it will make it run smoother from what I’ve heard.  I drove him to work today; what a feeling when everyone says just how beautiful your bike is. The guy who drives a moped was there too. He asked me to listen to his moped because it was making some noise. I figured it was his exhaust shield rattling, but the owner of the restaurant said “it doesn’t matter how much you rev that thing it doesn’t make it manlier”. We had a good laugh.

[TOOLS1]

I love those meaty Adventure Tires.
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