Project - CB Cafe'-R (1982 CB750 F)

[lucadortenzi]

hello again everyone, and thanks for your replies so far.
I finally got a space where to work on my project and will crack on this saturday attacking the carbs.
I am aiming to:
Clean the carbs and reinstall them by sunday;
Change oil and filter;
Get a new battery on;
Get the engine running by next weekend.

Any heads up/advice/tips you guys might have please shoot. I have experience with scooters and small motorbikes but this is my first  big project ; )
Thank you in advance!
Luca

[rich]

Sounds like a great weekend to me!

I just wanted to point out, in case you missed it, this carb cleaning guide that's on the Repair Manuals page of this forum. It's good some good information on cleaning the carbs:

DOHC carb cleaning run down Honda_Carb_Manual_revD.pdf

The oil and filter shouldn't give you any problems. Just be sure note the locations of the washer and spring that are in the oil filter cover and don't over torque the bolt when you put it back on.

[lucadortenzi]

Hello! Nice weekend spend cleaning the cabrs but still did not installed them. I might get a set of Mikuni's VM 34 or a kit of CR29 as some extra money are coming in.
Probably sell the set of stock carbs after a nice deep clean.

anyone knows how to check the conditions of the inside of the tank in case has leaks or it is a bit rusty?
Also, anyone has restored brake calipers  before?
I think that needs to be added to the list : p

[TOOLS1]

I would go with the CR 29s. As for your tank, just look inside with a flashlight, and you will see if it has rust.
TOOLS

[Re-run]

Brakes are simple. Take the calipers off the rotors first. Then while over a bucket, pump the handle to force out the pistons. Bucket is for the fluid of course. Open the top of the master and slowly pump a couple more times and most of the fluid should be out.

Disconnect the lines from the calipers and master and inspect those, likely they will need replacing. A local hydraulic shop should be able to make new lines for fairly cheap. I got my from http://www.helperformance.us/motorcycle/ they are very nice lines.

the manual should show how to remove the piston in the master, do this and clean it out, paying attention to the small return holes. Rebuild if needed.

You already have the pistons out of the calipers so clean the housings now. Remove the o-ring seal and make sure you carefully clean that groove. Corrosion builds up in the groove and will prevent the piston from retracting properly. Make sure the rest of the housing is clean. Clean and inspect the piston. Major pitting will require replacement. Minor pitting and flaking is usually fine. Get a new seal and put it in, then install the piston.

Get everything back together and on the bike and grab a big bottle of brake fluid. May as well use dot4 since it is better than 3. At this time, bleeding can begin.

[lucadortenzi]

Hi guys, hope you're all well. So stock carbs are clean and back on the bike. After installing a new battery and wired everything up I went to start the bike to realize I did not fill one of the cells. (do you know if I can just top that cell up and give it another charge or the battery is ready for the bin?

I also opened the clutch casing to realize that the oil coming out was full of sediments. Looks like the friction plates have been grinded to death. I have ordered new ones. Everything else looks fine in the clutch. What I would like to do is also flush the engine with some clean oil to get all those sediments out.
Any advice on how to do this? (I have the impression that the sediments are only in the clutch case and not in the rest of the engine or that would be a problem I reckon.

Re the brakes calipers, I am stuck with the cilinder inside. Looks like they are badly seased : (

Will also add some images. Look forward to hear from you chaps.

[shinyribs]

That's a gorgeous bike you have there, but that clutch is hideous! All the oil in these bikes mix together so I'd be cautious of that.  At least, maybe drop the oil pan and take a look around?

Good luck! Hope she cleans up easily. I love the blue on that bike.

[lucadortenzi]

Thx Shiny..is frustrating having such a nice machine and does not even run at the moment.
any idea of the best way to flush the engine? or i just clean up the cluch casing properly?

I also might add some new oil..and run the bike for a bit..then rechange the oil again?
Will get new clutch plates on wednesday and install/adjust the clutch.

Any more feedback also on the clipers are MORE than welcome. Cheers chaps.

L

[TOOLS1]

I would try filling the battery, and see if it will work, you have nothing to loose if it does not. On the brake, reconnect the caliper to the master cylinder, and use the master cylinder to pump the piston out. On cleaning the engine, take some brake clean, and spray the area around the clutch. All the crap will jusr run out. Then run some "Sea Foam" through the engine. Just follow the directions on the can, or do a searh on the forum here for "Sea Foam". It will be clean as new.
TOOLS

[lucadortenzi]

Ace, will try all of this tonight. Thanks!

[lucadortenzi]

Ok, so went to the workshop, and filled up the empty cell with some acid. Under charge now so let's see what voltage pulls out.

I have clean the clutch box and casing from all the sediment from the clutch plates. Will run some SeaFoam when I get it.

Also I have opened the Alternator assembly to find its content in these conditions:











Rotor and Stator are pretty expensive, i could do with saving on them from now..and see if the bike turns on ok and has no charging problems. Perhaps change them on a later date. I have cleaned the casing.
What do you guys think about cleaning all the rust with fine sanding paper?
How do you advice to clean the stator? WD40 could do?

Thanks all in advanced.

[TOOLS1]

 That case looks damaged where the bolt holes are for the cover.
TOOLS

[lucadortenzi]

Ouch you are totally right Tools. The cover was pretty stable tho. Any ideas?

[TOOLS1]

This is not the first case I have seen that looks like an arc welder went bezerk inside it. I guess if the cover still goes on, and seals, but all red RTV is an indication of it not being able to seal. You know a SOHC engine will bolt into your frame, just a thought.
TOOLS

[shinyribs]

That is a little scary looking,but it's won't take a whole lot to seal that area. It's not like it's under any oil pressure,it's just what residual gets tossed around in there.

Definitely get rid of all traces of silicone and , if it turns out you do need some type of sealant on there, I'd think about using some Three Bond or some Indian Head gasket shellac.

Always said to see one deteriorated from sitting.

[lucadortenzi]

Yes is looks like water got access to the Alternator..shaisse..
I should be able to cold solder and restore that bolt hole. I am just wondering about withstanding over 270 degrees C ( 500F ).
What is the red RTV? simply just the gasket?
Any trick on how could I clean the stator? I will try to see how all of this behaves with the charging and eventually get a new one.

Yes a SOHC engine would be sweet, but ain't in my budget at the moment, and not really finding many of them at the moment..any advice on where to look for one?

Thanks Tools

[lucadortenzi]

Yes it does looks like a mess Shinyribs..

I have ordered a new gasket and will reseal that area after cleaning rotor, stator and rebuild the bolt hole.
Any other piece of advice or warning will be super welcome.

Thanks lads

[masiste]

That is most unfortunate.

Looks as if your engine has been swallowing water, left unattended under a downpour, or ridden under rainy conditions with some opening sucking in water.

Perhaps the mess in the clutch plates is due to water damage.

I suggest taking the oil pan out like it was said before, to see if any other areas have that watery look.

Take valve cover off too.

Hopefully ot is not that bad.

Clean with W-D40  and hopefully rotor , stator and brushes are still good. A new set of clutch plates like you said will make it one working piece. Need pour oil on cylinders and valves to loosen them up under carefull cranking with wrench.

Many engines bend valves because after years of no use, guys try starting them just like that, w/o even loosening parts beforehand.

About the alternator cover, use a gasket...( on E Bay for about $7 bucks, bought one myself 2 days ago at dealer for $12 )...and forget about gooey silly cone.  I did repair once a moped engine case damaged thread like that with JB Weld, and a Heli coil insert. Get the appropriate size heli coil, and JB Weld it in place, that should be enough to hold that cover in place.

That is the thing about purchasing a vehicle that does not run.  a acquaintance of mine bought same bike, told it was running fine, jst being stored because of bad battery.

Upon changing oil, water came out of engine. It was full of water. Perhaps left out in rain with no valve cover on, no carburetors, you figure it out, but all full of water.

Do not dispear, just clean it good, and then rinse motor a couple times with engine cleaner and cheap oil to rid all water and contaminants out.

[lucadortenzi]

Golden words Masiste thanks.
Just a couple of questions:
For valve cover you mean the cylinder head?
Also shall I clean rotor and stator with wd40 only or give it a run with some fine sanding paper/steel brushes?

Then you're saying to pour oil from the engine top (after I remove/inspect the cylinder head)..

what do you mean for carefull cranking with wrench?

Got an alternator gasket already. Will need to re-build the bolt hole tho, any tips on how to do that?

I bought the CB for very cheap so I was ready for some surprises.

Look foward to hear from you.

Cheers

[masiste]

Hi

   The valve cover as I know it, is not the cylinder head, but the cover above it. That cover to which the tach cable affixes. Taking it out as if you were to adjust valves. Make sure it is lubed and free of water, moisture or foreign material.

  Take the spark plugs out too, and pour a spoon full of motor oil into each cylinder through plug hole.  Like this, you can later ..( let it soak a few hours)  ...use a wrench and turn the engine, so it will move and lube itself, pistons, cylinders, valve train, hopefully it will not be frozen.

  I would not remove the cylinder head unless engine was frozen.

  About alternator area, I would remove the rotor, stator, and clean area, with fine sand paper or a dremmel toll with a polish end, and then remove all dust and contaminants with WD-40, which is good for electrical conduction and water repelent.

  About the broken case, JB Weld and a Heli Coil the size of the stock bolt, could be used to affix thread onto broken case section. JB Weld os a cold mix that works like welding,  without the risks of actual welding, like high temp, meltdown of case, etc.

   Once the engine has been turned a few times with a wrench ( manually) and gotten lubed, you can get it started, and test rideen.

    Keep ot up .