Author Topic: 1978 CB750K — Post 836 OIL PRESSURE - Hopefully Good!? (Read 248355 times)

SKTP · « **Reply #775 on:** May 20, 2015, 11:08:19 AM »

Had to google "Serdi" but I think so — basically a valve job and media blasting — they will inspect it for anything else (Valves? Springs? Guides?)

I'm not building a race machine. I just want to never take the engine out ever again — then buy an RC51

SOHC4 Cafe Racer Fan · « **Reply #776 on:** May 20, 2015, 01:21:35 PM »

Amen to not having to pull the motor again. I've had to do that a couple of times on the same bike. No fun. I think that the guys at APE will let you know if other work is necessary. They have a wealth of experience with the SOHC/4 motor.

And yes, the RC is still available.

brandEn · « **Reply #777 on:** May 20, 2015, 05:04:24 PM »

Here is some useful info from Cycle X on transmission gears.

http://www.cyclexchange.net/GearIdentification.htm

SKTP · « **Reply #778 on:** May 27, 2015, 07:13:58 PM »

Seat completed. Cannot wait to actually see it (Ships tomorrow). It's a stock 78K pan cut down to work with the F tank.

Upholstery by http://newchurchmoto.com

SKTP · « **Reply #779 on:** May 29, 2015, 06:23:24 PM »

Today's update — got a call from APE. They asked "How much was this engine smoking?" Valve job, guides and springs happening.

If it was that bad and still ran pretty well, I can' wait to see how it runs after all of this

Restoration Fan · « **Reply #780 on:** May 30, 2015, 05:00:31 AM »

Looking forward to seeing it all back together too. Keep up the good work.

SKTP · « **Reply #781 on:** June 04, 2015, 09:12:55 AM »

My first attempt at a custom seat is back from the upholsterer...It turned out pretty nicely. There's a small gap at the bottom between the tank that I could have done with out (my fault in pan and foam cutting) but I doubt most people will ever notice...overall I am fairly happy

SKTP · « **Reply #782 on:** June 04, 2015, 09:14:10 AM »

oh yeah, why is my tank latch not catching? It used to and now its not...nothing changed...have to investigate. have to move garages AGAIN!!!! 4th time during the build

SOHC4 Cafe Racer Fan · « **Reply #783 on:** June 04, 2015, 10:19:12 AM »

No substantial gap is apparent between the seat and tank from the photos, so I don't think it's anything to worry about. The seat looks nice, Chris. Did the upholsterer move the plunger? It might be moved or bent slightly preventing the latch from operating properly.

SKTP · « **Reply #784 on:** June 04, 2015, 10:23:59 AM »

not the seat latch...that works fine, the tank lid...it worked when I got it back from the painter then nothing happened. I thought storing it with the lid open was a good idea, now it won't catch. I'm sure i'll figure it out...but it's really odd since really, nothing happened at all. I put gas in the tank. that's it

The seat somehow looks smaller in person than in these photos...I'm also hoping once the engine and exhaust, etc...are all in it will balance out more...it's comfortable and can support 2-up riding...so I think mission accomplished

SOHC4 Cafe Racer Fan · « **Reply #785 on:** June 04, 2015, 10:30:53 AM »

Oops, I guess I had seat on the brain. Did you check the condition of the spring (U-shaped latch that catches the plunger on the tank? It may have slipped out of alignment or snapped.

SKTP · « **Reply #786 on:** June 15, 2015, 09:37:49 AM »

Figured out the tank latch...you have to bend the "spring part" up like an upside down "U"...works perfectly bent up but not at all when flat

edit: thought I'd put them side by side. I'll be able to swap on the K tank and Giuliari seat still. All mounts are stock. Will be selling a recovered stock 78K seat, more than likely...

SOHC4 Cafe Racer Fan · « **Reply #787 on:** June 15, 2015, 10:03:26 AM »

Chris,

I really like how the tank paint goes with the frame color. I think you have just the right amount of color. I was thinking what it would look like if the headlight bucket and ears were painted blue, too, but I think that would be too much. It seems to have a good balance. Now for that motor!!

SKTP · « **Reply #788 on:** June 15, 2015, 10:05:00 AM »

Thanks! I am very happy with the colors. I am waiting for my head from APE. Any day now...

SOHC4 Cafe Racer Fan · « **Reply #789 on:** June 15, 2015, 10:15:38 AM »

We'll have to take our bikes out for a ride together one of these days.

SKTP · « **Reply #790 on:** June 24, 2015, 09:50:25 AM »

Got my head back from APE! Valve job and resurfacing. They were fantastic to deal with. Great communication.

I just emailed them but thought I'd ask here too...

What are these 2 things and where do they go? They came with my head. (I know what the dowels are)

edit: I guess they are #6? I will have to do some reading

12238-300-010 ORIFICE, OIL CONTROL (NOT AVAILABLE)

madmtnmotors · « **Reply #791 on:** June 24, 2015, 10:25:46 AM »

+1

You are lucky they were not lost. They are required.

SKTP · « **Reply #792 on:** June 24, 2015, 10:32:41 AM »

Pat from APE returned my email with in minutes with photos from HONDAMAN's book (which I own). I have some reading to do

Thank you Pat, APE and Hondaman!

SKTP · « **Reply #793 on:** June 28, 2015, 07:15:02 PM »

Do these need to be replaced? I am finding most info about these to be pretty confusing....

Davez134 · « **Reply #794 on:** June 28, 2015, 09:12:16 PM »

The first and last pic look suspect, from the photos they look scored pretty deep. Also appear to have small gouges. The middle two don't "look" horrible, but the only way to tell is to plastigauge them.

SKTP · « **Reply #795 on:** June 28, 2015, 10:49:52 PM »

I agree that the top and bottom ones are scored (they are a matching top and bottom). So if I replace them, I might need to buy different sizes and mix and match? And ultimately not use a couple (or more?). How often do these lead to engine issues? Do most people buy all greens and hope for the best? Replacing all 10 could get pricey really fast...especially if you needed 2 or more sizes of each, if I'm following the logic here (since you can't know if it's the right tolerance until it's in and checked) right?

Edit: I'm still wrapping my 11pm Sunday night head around this...I guess if the crank shaft size is known and the plastigauge shows the gap, you can figure it out in one shot? I need to rethink this in the morning

RAFster122s · « **Reply #796 on:** June 30, 2015, 08:26:38 PM »

Yes, plastigage on the bearing surface across to get a read on the clearance of the crank and bearing shells. Measure all of them and you can then know based on the plastigage charts your clearance for each bearing shells and the crank. That then gives you the measurement and you compare that to the sizes available to choose the correct ones for replacement.
You will have to torque the crank down to spec to get accurate readings. Just be sure it is surgical clean before you button it up.
Good luck.
Or, spend silly amounts of money for ridiculous performance having the crank balanced and lightened and that gorgeous knife edge treatment. APE can hook you up as they do beautiful work and can ensure your crank is tip top.

David

SKTP · « **Reply #797 on:** July 01, 2015, 10:07:23 AM »

No more money...I'm tempted to just bolt it all together...but I will plastigauge them...no sense going this far and half-assing it

SOHC4 Cafe Racer Fan · « **Reply #798 on:** July 01, 2015, 10:25:40 AM »

There's a point at which you shake your head at the $$$$ you've put into the motor.

Q: How fast do you want to go?
A: How much do you want to spend?

I think the knife edge might be nice if you have extra $$ burning a hole in your pocket, but if NOT, then get your bearings sorted and put her back together!

MCRider · « **Reply #799 on:** July 01, 2015, 10:39:23 AM »

Quote from: CB750 Cafe Racer Fan on July 01, 2015, 10:25:40 AM

There's a point at which you shake your head at the $$$$ you've put into the motor.

Q: How fast do you want to go?
A: How much do you want to spend?

I think the knife edge might be nice if you have extra $$ burning a hole in your pocket, but if NOT, then get your bearings sorted and put her back together!

The knife edge is nice for bragging rights. But many of the drag race ilk say you'll get a better launch with some weight left on the crank. This is bigger point than the advantages of knife edge. A little more weight good for street too. Road race about only place for knife edge.

Weight removal best done to alternator as they have been known to break the crank. Otherwise, remove whats necessary for balance and go home.

News:

Author Topic: 1978 CB750K — Post 836 OIL PRESSURE - Hopefully Good!? (Read 248355 times)