Author Topic: 1972 CB750K2 (start from scratch) project. Cases back together (Read 102441 times)

SOHC4 Cafe Racer Fan · « **Reply #400 on:** June 02, 2015, 11:23:59 PM »

Quote from: Davez134 on June 02, 2015, 09:19:40 PM

Quote from: CB750 Cafe Racer Fan on June 02, 2015, 09:53:27 AM
Hey Dave,

What's left or is there anything left to button up? Or are you busy riding it like you stole it?

Great bike!

Nothing left, just riding it. Mornings only now though, getting in to the 100's temps here now.

Oooof! Vegas baby, Vegas.

Davez134 · « **Reply #401 on:** June 04, 2015, 10:14:41 AM »

So, I am going to embarrass myself to save someone else any problems/headache in the future. The only leak I have from this motor is from the crankshaft oil seal. I thought I fixed it by lightly tapping it in and squaring it up in its place but leak came back even worse when I rode it hard last week. Now I know why. Look at this picture, I installed the damn thing backwards!!!

The metal ring is supposed to face inward! The oil seal I got from cycleX did not have a pronounced lip on one side to make it obvious, and I had never used a seal with a metal ring in it before. I know the "open end" of a seal should generally face toward where the oil is. I now realize, when the metal ring is removed that this is the open end.
I ordered some universal 30x42x8 crankshaft oil seal without a lip, cleaned area, applied hondabond lightly to surface and drove it in slowly and evenly with a piece of PVC and dead blow hammer. The right direction this time.

Hope this works. So far so good.

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SOHC4 Cafe Racer Fan · « **Reply #402 on:** June 04, 2015, 10:57:11 AM »

Good on you for pointing it out so that even one person doesn't do the same.

edwardmorris · « **Reply #403 on:** June 04, 2015, 12:48:35 PM »

I used the OE seal and it had that lip, so I feel better about installing, but not sure enough, so I'll pull the advancer and check closely.

Retro Rocket · « **Reply #404 on:** June 04, 2015, 03:24:31 PM »

Quote from: Davez134 on June 04, 2015, 10:14:41 AM

So, I am going to embarrass myself to save someone else any problems/headache in the future. The only leak I have from this motor is from the crankshaft oil seal. I thought I fixed it by lightly tapping it in and squaring it up in its place but leak came back even worse when I rode it hard last week. Now I know why. Look at this picture, I installed the damn thing backwards!!!

The metal ring is supposed to face inward! The oil seal I got from cycleX did not have a pronounced lip on one side to make it obvious, and I had never used a seal with a metal ring in it before. I know the "open end" of a seal should generally face toward where the oil is. I now realize, when the metal ring is removed that this is the open end.
I ordered some universal 30x42x8 crankshaft oil seal without a lip, cleaned area, applied hondabond lightly to surface and drove it in slowly and evenly with a piece of PVC and dead blow hammer. The right direction this time.

Hope this works. So far so good.

Sent from my iPhone using Tapatalk

Dave, in this order mate, seal first, beer second....

Ravie · « **Reply #405 on:** June 04, 2015, 03:28:39 PM »

I used a small amount of aviation permatex on the outside of mine. Hell no to leaks! Lol.

We will find out in a week or so.

Davez134 · « **Reply #406 on:** June 04, 2015, 03:50:22 PM »

Quote from: Retro Rocket on June 04, 2015, 03:24:31 PM

Dave, in this order mate, seal first, beer second....

I thought I worked better after a couple. Apparently not!

Retro Rocket · « **Reply #407 on:** June 04, 2015, 03:54:23 PM »

Quote from: Davez134 on June 04, 2015, 03:50:22 PM

Quote from: Retro Rocket on June 04, 2015, 03:24:31 PM
Dave, in this order mate, seal first, beer second....

I thought I worked better after a couple. Apparently not!

At least you've got it sorted out now....

Davez134 · « **Reply #408 on:** June 05, 2015, 12:25:46 PM »

We'll see. I did take it out right after driving in new seal, ran it pretty good, 20 miles or so, 80-90 mph, rpm's up, no leaks yet. I was going to put some more miles on it this week, but I just separated my shoulder and fractured part of scapula. No riding for a bit. At least it wont leak just sitting there!

Davez134 · « **Reply #409 on:** June 10, 2015, 04:25:36 PM »

Shoulder has been feeling good enough to ride since installing crank oil seal without separating cases. I don't want to get too optimistic yet but...
Since driving in new crank oil seal

Dry boot...

Dry engine

I ordered extra seals just in case though

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SOHC4 Cafe Racer Fan · « **Reply #410 on:** June 11, 2015, 12:56:15 AM »

Good to hear. Knocking on wood that the fix is solid.

Davez134 · « **Reply #411 on:** June 16, 2015, 12:00:39 PM »

I've been using reproduction gauges from z1parts.net on this bike. They look great, the speedo is perfect, tach is ok, but bounces like crazy above 5500 rpm. They sent me another one no questions asked but it did the same thing. I think this is why... No dampening pot

So I switched the face plate over to a honda tach so it would match speedo, painted housing, crimped back together, used back plate from reproduction. Came out pretty damn close

Taking it to my first vintage bike show on Friday

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SOHC4 Cafe Racer Fan · « **Reply #412 on:** June 16, 2015, 12:24:35 PM »

Pretty damn close, indeed.

Ravie · « **Reply #413 on:** June 24, 2015, 11:57:20 AM »

My original tach gets "stuck" after revving. If i tap it it will slowly come back down. Can you shed any light on why that might be?

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Ravie · « **Reply #414 on:** June 24, 2015, 12:48:28 PM »

Lol, what? Hahaha. I suppose I have to take it apart to rectify that?

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edwardmorris · « **Reply #415 on:** June 24, 2015, 12:50:33 PM »

Quote from: calj737 on June 24, 2015, 12:35:45 PM

Low on damping fluid. Or, you're not holding your mouth right?

Late K2 and later years didn't have the damping fluid set up, much simpler insides.

edwardmorris · « **Reply #416 on:** June 24, 2015, 12:52:25 PM »

Quote from: Ravie on June 24, 2015, 12:48:28 PM

Lol, what? Hahaha. I suppose I have to take it apart to rectify that?

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If you do take them apart, be careful with the crimp rings, save them and reuse, much easier during assembly. Lube up the mating gears while in there too. I can dig up a link to a pictorial if you need it. Pretty sure I posted it somewhere in the FAQs.

edwardmorris · « **Reply #417 on:** June 24, 2015, 12:54:38 PM »

Quote from: calj737 on June 24, 2015, 12:53:50 PM

Quote from: edwardmorris on June 24, 2015, 12:50:33 PM
Late K2 and later years didn't have the damping fluid set up, much simpler insides.
Tattletale! Can't you just see him now, looking and looking, and looking? Kind of like telling a newbie, "To use the rattled an spray paint, gotta shake it until the rattle stops".

DRAATS! that would have been fun

Davez134 · « **Reply #418 on:** June 24, 2015, 01:10:45 PM »

Quote from: calj737 on June 24, 2015, 12:56:49 PM

Sh!t, Dave. I'm sorry, I actually thought this was Ravie's thread. Please pardon the horseplay in yours.

Never apologize for horseplay to me! Keeps us lively. That, and talking sh*t are the only things I'm good at!

On a serious side, Marcel (cb750faces.com) has 2 great YouTube vids on opening/closing gauges.

Ravie · « **Reply #419 on:** June 24, 2015, 01:19:42 PM »

And then I wonder why so few people dig my thread... hahaha

Cool guys. I'll read up.

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Ravie · « **Reply #420 on:** June 24, 2015, 02:12:41 PM »

I honestly don't even know what that means. Some sort of easterner slang? lol

Davez134 · « **Reply #421 on:** June 24, 2015, 03:33:36 PM »

Quote from: Ravie on June 24, 2015, 02:12:41 PM

I honestly don't even know what that means. Some sort of easterner slang? lol

I'm not sure what it means out there in Kansas, and maybe I don't wanna

Ok I'll explain I guess haha. It doesn't mean anything really, just something you say to mess with someone when they can't figure out why something they are doing isn't working. Next time you are turning a wrench, trying to get something in place that doesn't wanna go, just consciously think about the weird way you're holding your mouth and you'll get it.

BTW, I like all this other bs going on in the thread, it means I'm not having issues with the bike!

Ravie · « **Reply #422 on:** June 24, 2015, 03:48:20 PM »

AH! Ok. I had never heard that expression before and in text it's hard to really get the intent...

As a guitar player AND a mechanic...you can be damn sure I'm good at making faces!

Well good, come on over and finish mine then, would ya? hahaha

Davez134 · « **Reply #423 on:** July 28, 2015, 10:16:00 PM »

Today, my wife finally took some good pictures of the bike, since all I have is cell phone pictures. I have been riding it daily and it is running GREAT!!!

SOHC4 Cafe Racer Fan · « **Reply #424 on:** July 28, 2015, 10:28:27 PM »

Quote from: Davez134 on July 28, 2015, 10:16:00 PM

Today, my wife finally took some good pictures of the bike, since all I have is cell phone pictures. I have been riding it daily and it is running GREAT!!!

Kudos to the wife. Those are outstanding shots!

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Author Topic: 1972 CB750K2 (start from scratch) project. Cases back together (Read 102441 times)