Topic: Top cam cover removal.

[maxheadflow]

So you have to pull the motor on a K8 to get the valve / cam cover off?   Last top end I did on a CB750 was a brand new CB750A.  IIRC I didn't have to pull the motor. Maybe just drop the motor in the frame by removing the motor bolts?

[seanbarney41]

yeah, the Automatic frame allows for top end removal...Not really possible with any other sohc 750.

Actually, I did a valve cover gasket once by tilting the engine forward in the frame...it was probably as much or more work than just pulling the engine out.

[BenelliSEI]

+1. I did it once and I’m sure it was more trouble than pulling it!

[maxheadflow]

Thanks guys.  Come to think of it I don't remember doing a top end on any other CB750.  I did do a set of engine cases on a roomates K1 but at that point the motor had to come out.   IIRC 500 / 550 top ends could be done in the frame tho I guess the carbs / air cleaner were a bit of a pain.   

I've got the valve cover loose thinking I could remove it so might as well try cheating..    That motor is damned heavy and I ain't getting any stronger.

[Stev-o]

You could install a frame kit, then the top end will come off w/o pulling the motor.

Frank/Scott makes a nice "weldless" kit...

[maxheadflow]

You could install a frame kit, then the top end will come off w/o pulling the motor.

Frank/Scott makes a nice "weldless" kit...

I take it that you have to cut the 2 lower frame rails in the neck?

[scottly]

Yes, you cut the tubes and the triangular piece.

[disco]

Frame kit is a good modification imho.

[Terry in Australia]

If you've got access to a set of old forks, you can make your own frame kit for cheap without losing the rigidity of an uncut frame, and it can always be taken back to original later on.

Sunday Swamp Rat reassembly 4 Aug 2019 6 by Terry Prendergast, on Flickr

[scottly]

Just how close of a fit are the fork tube chunks over the frame tubes, Slim?

[754]

 I am willing to put the Frank/Scott kit up against any other kit for a rigidity test.
 If it's Good enough  to hold your forks  on to your bike , it's probably clamping pretty good.

[PeWe]

Very convenient with frame kit!
My K6 got Franks kit after I have had som thoughts about cutting the frame. Since bike is a ride bike, not museum or collectors bike the decision was easier.
I had an urgent need of replacing cylinder studs and another jobs.

I have after that had great use of the kit lifting top end plenty of times. Also easier to pull engine and put it back in again. One man job. I remove head, cylinder with pistons and cyl studs, then loosen the bolts holding the engine and wrap a strap around it and lift it out, swinging onto the floor and let i land on thick wooden plank. This when the entire engine was to be opened.

Last job I did the engine job opened it completely on the floor. Then back into the frame, building it up in there with pistons, cyl studs,cylinder (Mike's Billet block) and head. Timed cam in there too.

My last build, a K2 had frame cut since the 80's. It got Franks kit too. I have already used it when switching head 4 months after the build was ready.

I prefer to have tubes cut so the ignition switch can be fitted, rear tube cut to make the biggest opening.
Here how I did it on my K6 that has been used more than I can remember (change cam a quick job, fine when testing several hot cams)
planning the cuts: http://forums.sohc4.net/index.php/topic,62832.msg1505097.html#msg1505097
when done: http://forums.sohc4.net/index.php/topic,62832.msg1515860.html#msg1515860

[Terry in Australia]

Just how close of a fit are the fork tube chunks over the frame tubes, Slim?

G'Day Scott, It was very close, but I had to slit each section to pull it down nice and tight. With the 4 x 6mm stainless screws drilled thru both the frame sections and the 6mm thick steel sleeves at each intersecting section, it's super rigid. I remember seeing a frame kit here with hose clamps holding the sleeves in place, and thinking, "How useless is that?" but with bolts passing through the whole deal, it's super rigid, and importantly, a cheap fix.

I re-installed the engine last weekend, and with the gap afforded by the removal of the frame section, it was a piece of cake. Once this bike is done, I'm gonna make another frame kit for my K2 bitsa so I can fix the weeping cam cover gasket. Luckily I've got another rusty set of forks to chop up, so the only cost will be the 20 new stainless nuts and bolts.  

[754]

 Here is what you have for clamping, its not pulling it round and from the bolts to the slits is not pulling tight. .
 Not to mention you have to drill 16 extra holes, not easy to get them straight I am thinking.
 And you have to remove 20 bolts and nuts, on Scott's you remove 4 bolts and nuts, on mine..only 4 bolts.
 The rest you loosen a turn and slide clamp back  no fumbling or dropping nuts or washers. .
 But hey it works,  and you are happy.  Pull all 4 out switch them around, see how it fits now..
 Scott and I don't use steel for straps and clamps, because we don't want extra weight.
 With 2 T handle Allen wrenches, our kit  allows frame section out,  in 2 to 3 minutes.

[scottly]

Terry, keep track of All your time, and apply your rate from your day job. Now how cheap is your kit?

[Terry in Australia]

Ha ha, Frank, it clamps down fine, the fork tubes are such a close fit to the tubes it only needs to pull down maybe 1mm? Disregard the slots, I cut them with an angle grinder and they're a bit wobbly. way more rigid than an alloy clamp on the outside, and as I use my Dewalt rattle gun to undo/do up the bolts, it takes about a minute to install/remove.

I didn't mark which ones went where when I took them off, but didn't need to. I measured the distance on each set before I drilled the holes, so it doesn't matter where they go. Weight wise, I guess they weigh a couple of pounds? I've lost 141 pounds since this time last year, so a couple more pounds on my CB750 won't make a lot of difference, methinks? The good thing is, anyone with an old set of forks and basic tools can make them.

Scott, I play with bikes as a hobby, not a business, so I don't worry about how long anything takes to do, but I suppose it took me an hour or so to make these? I've got lots of rusty old forks here, so I won't run out of prospective frame kits for a long time.....        

[754]

If there  is anywhere near 1mm clearance, there is not much of the fork tube touching the frame tube after you tighten it..
Not wrapping tight  less rigidity..

[scottly]

Terry, like I said, keep track of all your time on the next set; I think 1 hour is grossly understated given your available methods.
My clamp bores are within .010" of the tube OD...

[PeWe]

Frank's kit is easier to undo in the future if going back to bone stock. The only mtrl missing is the thickness of the saw blade and 4 bolt holes.

I understand Terry when he has machines and parts to be used for a quick fix instead of order a kit and need to wait 2 weeks for delivery.

[Terry in Australia]

If there  is anywhere near 1mm clearance, there is not much of the fork tube touching the frame tube after you tighten it..
Not wrapping tight  less rigidity..

Nah, it's tight all the way around Frank, so yeah, probably only a few thou, and as opposed to relying on an alloy clamp to hold it in place, the bolts that pass through the whole assembly make it a much more rigid structure. Yours are much nicer looking though.

[754]

 Pity we have springs in our forks, you could be using your method  to make your own triple trees...

 Ever put a set collar on a shaft with one screw, you can wiggle it, if you have 2 setscrews 180 apart, you can still wiggle it...... now bear in mind set collars are short.
 Now take same set collar with 2 screws 90 degrees apart, no more wobble. .

Now on the other kits made, and on Terrys example, there is a small flaw in manufacturing process, that can affect rigidity, I will leave  it to you to figure it out...  I eliminated that factor.

[Terry in Australia]

Yeah, it's a bit like why we have cylinder studs that go thru the cylinder block to hold them down, rather than just clamping them down on the outside frank, your method looks nice, but doesn't really provide any strength. Look nice though.

[754]

 I am not the sharpest pencil in the box, but even I know there is a difference between clamping flat pieces and round pieces...

[maxheadflow]

Thanks guys,

You convinced me to pull the motor. 

[scottly]

If you're going to pull the motor, you might want to check out the C-hook lifting things members have come up with:
http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742