Half-Caf: my '80 cb750f SS cafe project

[Half-Caf]

So, as of a couple days ago, it was determined that I would not have 1, but 2 roommates this summer!
That means no more motorcycle parts scattered EVERYWHERE in my apartment.
I pooled them all into one place and figured I would share a sneak peek at what is to come -mind you that these do not include all my crap in the garage or my project room.


Some of you observant types will notice some new goodies

[cdaiscool]

Wait, do I see 2 sets of carbs?

[Half-Caf]

cdaiscool wrote

Wait, do I see 2 sets of carbs?

Sure do. Did you think you were the only one who got the "Tools special"

[Half-Caf]

So I was able to do a little more work today.
Still haven't really torn into the engine, but the weather has been great, so I painted a couple parts today (aluma-hyde requires some heat to cure properly)




I decided to use this stuff on some high traffic and high heat areas. It is self-priming, and supposed to be pretty tough (should be @ $20 a can  )

Also, I trimmed a little more fat off the headlight lens today.



What I really needed were some side profile pics. It's hard to tell, but I trimmed off ~1.5" that attributed to the height. Now it's basically just a flat lens.

AND... I worked on putting another nautical star on my left side cover. I promised I'd take more pics so you could see the steps this time, but you will have to wait until tomorrow as I'm not completely done yet.
I'll tempt you with this for now

[shinyribs]

Never heard of aluma-hyde but I like it. I also dig your bubble-wrap star

[Half-Caf]

If you're interested, this is where I got mine.
2 cans ended up being $40 shipped.

[Half-Caf]

Ok, time for that Write-up on the Nautical star tape job. I tried to take lots of pictures, so I will let them do the talking.
Before you do any real tape work, make sure you get some good automotive tape and some sharp razor blades. All of the cuts I made were freehand with loose utility blades.


Step 1: outline shape and cutout center


Step 2: make a smaller star inside that one and cut off excess tape. This will be the star's border.


Step 3: tape across the star with the edge of the tape lining up with the point and opposite indent. This step looks a little confusing, but these lines will be helpful in the next step!


Again, trim off the excess.


Step 4: Now cut along those straight lines you made in the last step. See the Nautical part starting to show?


Step 5: cut out the final little triangles and you're done! Those lines you taped in step 3 will also act as a guide for this step.

Now clean up those edges and hit it with some paint!

[Half-Caf]

In other news, I received my new tapered bearings and fork seals from allballs today.
Now just to decide on fork oil


Apparently the F2 (my forks) shipped with 10W fork oil. However, it looks like changing it out to 15W was popular for those who like a firmer feel.
The F2's dry weight is 407lbs as opposed to the cb's 520lbs. Also, I'm no heavyweight @ 160lbs.
I'm thinking that given the extra mass of the 750, I should be ok with the 15W.
What do you guys think?

[Piute]

                                                                 8.50



                                           most any non-specific/dealer bike shop

[shinyribs]

''This step looks a little confusing''...well said Love that star you do. I would steal it,but you all would see it so... I won't.

You are still running clip ons,right? When you lean on your bars like that (like my clubmans) you put more weight on the bars than the guys cruising with stock bars,obviously. When I first put my progressive springs in I was kinda disappointed that the front end still a little too firm.My original springs were bottoming out and banging before.Real harsh on my palms.I wasn't getting the plush ride I was hoping for with the progressives. I told Eric who I got them from and he suggested I run thicker oil in the forks cuz of the clubmans and my size. I'm 225 lbs...occasionally...it fluctuates depending on the Holidays. The oil helps controls rebound-forks coming back up.I put 15wt in mine and it helped a bunch. It seemed strange cuz i thought the firmness i was feeling was too firm on the compression.It wasnt.It was too soft on the rebound allowing the forks to jump up into my palms. The thicker oil slowed the rebound down and now my palms dont get the same harshness as before. I havent rode much with this setup,but the results were immediately better. Handling seems more predictable too since the front suspension cycles smoother and slower. Before,if I was cornering hard and the front end hit some bumps it feel kinda unstable,like the tire was skipping.But now it seems like the front tire follows the road better,without the harsh skippy feeling. So,apparetly 15wt oil is thicker than the ATF I was running. I'm tempted to try some 20 wt,but with the clumans I have to pull my bars off to change the oil and thats a pain. Your weight should make a big difference on this. Since you are 60+ lbs lighter than me I dont know if the 15wt would be too much or not. I am happt with my 15wt,but fell like it could use more. Not sure until i try,though...finger cramp!owowow

[Half-Caf]

shinyribs wrote

You are still running clip ons,right? When you lean on your bars like that (like my clubmans) you put more weight on the bars than the guys cruising with stock bars,obviously.

Ribs, as I am running a sport bike front end, clip-ons are the stock offerring. Even though I'm not that heavy, I'm still considering the 20W just because the bike itself is a good deal heavier.
That and also more damping does not sound like a bad thing.

On a different note, I began my engine teardown today! I had a buddy from church over and we lugged the beast downstairs into my kitchen (which now smells like grease and blaster  )
A tall stand/table rigged with a couple lights overhead made for a fine operating table. I already had the valve cover off, so we got to work unloading the head and doing LOTS of bagging and labeling.
Here is what things looked like after we were done with the head.

Didn't look too shabby to my untrained eye...

Taking the head apart was almost easier than getting it off the bike. After I made sure all the necessary bolts were removed, I used a rubber mallet and hit upward on the "cam housing" just above the fins. Perhaps a photo would help, but alas, I didn't get to take as many as I would have liked

Here are a couple shots of the cylinders after I removed the head:



And after I popped off the gasket:


Anyone have any tips about how to clean up old, crusty gasket remains? I will be facing a lot of these and I want to clean things up nicely without causing any damage.

[Piute]

  HECK your already in the kitchen  OVEN CLEANER(lemon scent)

[Half-Caf]

Oops, forgot: I tried to remove the cylinders before I left for work, but they did not seem motivated to go anywhere. Any tips on getting the entire assembly off the case? Unlike the head, there are no surfaces safe for me to bang on with a mallet.

Another question: What are your opinions on cleaning out the carbon buildup at the top of the cylinders? I was reading online and found that you shouldn't do that unless you're replacing the rings also

random forum wrote

The carbon ring inside the cylinder acts like a seal to the piston rings on the cylinder. As the rings wear the carbon builds at the top stroke due to gases and oil blowby from the rings. This carbon helps the worn rings on the compression stroke on the detonation of the fuel.

I wouldn't have any problem replacing the piston rings if they weren't so freaking expensive. Cheapest I found was $25 for one piston  
I don't know much about these -should they be replaced?

[Half-Caf]

Sorry for the spastic posting tonight, but after reading this post, I think I am just going to buy new rings and hone my cylinders.
I found a set of rings on eBay for $75. No-namers, but they should work.

EDIT: I previously mentioned a big bore kit, but I have decided against it.

[shinyribs]

If your cylinder walls are nice and smooth,with no scratches running up and down,your rings are fine. Removing carbon is never a bad thing as it can actually be abrasive. If your engine is relying on carbon build up to seal the compression around the rings...well...that goes without saying.

Oh,and don't draw the line AT ALL.Go fer it! $130 looks like a great price.Figure out what it would cost to get the boring done,though.

[cdaiscool]

Drawing the line over $50 + boring?

Big Bore kit for my 750 is quite a lot more. You're lucky.






GO FOR IT!


Cliffs: GO FOR IT!

[Half-Caf]

cdaiscool wrote

Drawing the line over $50 + boring?

Big Bore kit for my 750 is quite a lot more. You're lucky.

Oh contraire, my friend: http://www.ebay.com/itm/130626398925?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_1210wt_891



A brief update on my current status:
-I got the cylinders off. I will post pics and a couple tips tonight.
-One piston does not want to give up its pin. I am afraid to use too much "motivation" as I don't want to hurt my rods/crank
-I am out of plastic bags  (going to get some +oven cleaner now)
-Working on getting the clutch disassembled.
-Goal for today is to have everything off the crankcase so it's ready to be split tomorrow.


BTW, you guys are like the devil on my shoulder...

[TOOLS1]

That is the same seller I got the 836cc kit from, for my buddies bike. His machine work, boring, and valves came to $340.00.
To remove the pin make a puller out of a 1/4" bolt, some washers, and a socket/piece of pipe.
TOOLS

[cdaiscool]

That's a decent price. They cleaned/checked the valves to make sure none were bent? That's awesome, if so.

The big bore kit I need is the 823 kit. Here's where I've been eye-balling:

http://www.cyclexchange.net/DOHC%20PARTS%20pAGE.htm

The link you posted is oversize, not sure if its stock oversize, or an 823 kit...

[Half-Caf]

Still not sure what I think about the big bore idea...
My current piston rings seem to be in good shape, so I don't think I would even need to get new ones.
Also, with a big bore kit, I would be spending $150 for the pistons, maybe another $50 on the bore, and potentially having to buy a jetting kit and go through the whole carb-tinkering phase (not my favorite)

I guess what I meant with the "draw the line" comment earlier was that there's a lot of crap that comes with  going the big-bore route. I will already be adding 150cc's to my stock setup with this engine -I think I can roll with that and be perfectly content with what I've got.