Topic: 1972 CB750K2 (start from scratch) project. Cases back together

[edwardmorris]

Was it for sure that seal that was leaking and not just chain lube? My center stand gets greasy and I clean it every few trips, but its easy to tell its the chain lube based on how stringy it is (Lucas brand I think). The black paint could be hiding it, but that area looks too clean for an oil leak to me,  unless you already cleaned it before the pix?

Yeah, I'm sure it's not chain lube. And it's not coming from oiler hole either, I left the tray out and plugged the hole as well. The pic doesn't show it well, but it's oily as #$%* in there.

Cool. Just for added sealing, apply a thin coat of Hondabond/Permatex #2 on the outer surface. I'm pretty sure I did that, will have to go back and check before I get to the K3.

[Davez134]

I did apply hondabond to outer surface. It was actually leaking from around shaft part of seal. Maybe got tiny damage somehow when installing?? I'm going to use permatex this time outside, as it seems like it may lube better installing, then seal too.

[Davez134]

To get proper clearance, I removed shifter cover and foot peg.

Made tool to hit it in with, got to play with my new cut off saw.


Covered splines with tape, assembly lube on inside, non hardening dealer on outside of seal.



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[evanphi]

That's a tiny chop saw!

[Davez134]

That's a tiny chop saw!

Ha ha. I can't tell if you're joking or not because it does look small in that picture but it is 14 inch and heavy!!

[evanphi]

I'm used to larger bases for woodworking. Yours must be for cutting steel?

[Davez134]

It actually uses same blade for steel/aluminum, plastics. You can touch the steel right after cutting and it doesn't burn your hand. It's an evolution/rage blade and saw. Haven't used my DeWalt saw since I got this one.

[Davez134]

So, I think the reason this seal was leaking was the inner lip location. Compared to the OEM self I just put in, the lip was further out toward the end of splined shaft. It was just about where the splines start. The genuine seal inner lip is a few mm back toward smooth part of shaft. The original one I put in came in a kit from cycleX.

[MRieck]

The only thing I'd add is cut the corner off a plastic sandwich bag and cover the splined shaft. It will help prevent tearing the seal lip as you slide it over the shaft. Just pull it out right before you set the seal. It just noticed...sliding it over the shaft, pulling it out...never knew working on replacing a seal was so much like sex.

[Davez134]

The only thing I'd add is cut the corner off a plastic sandwich bag and cover the splined shaft. It will help prevent tearing the seal lip as you slide it over the shaft. Just pull it out right before you set the seal. It just noticed...sliding it over the shaft, pulling it out...never knew working on replacing a seal was so much like sex.

sandwich bag would have been a much better idea than the tape I used. Yeah, my mind is dirty too...the only difference between all that you just said about the bike and sex is that with the latter, I dont swear, get angry and want to punch or throw anything during or after. Yet.

[Davez134]

Got a chain guard finally. Had it powder coated in a fine texture black because it had some rust pitting that would have showed if done in smooth gloss.



Matches the texture on my motor pretty close too



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[evanphi]

WOW!

[SOHC4 Cafe Racer Fan]

Looks good Dave.

[MRieck]

Looks good Dave.

I agree

[el pachuco]

Got a chain guard finally. Had it powder coated in a fine texture black because it had some rust pitting that would have showed if done in smooth gloss.



Matches the texture on my motor pretty close too



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Another beautiful bike!!
I recently sprayed my chain guard with rattle can bed liner. It looks very much like yours.  I like it much better than gloss black.

Also, I read where crimping the gauge halves back together kicked your butt.
I just did mine today. I used a piece of 4" PVC pipe (2" long ), sitting on a ' round plywood base  for the upper half to rest in and a 12" speed clamp to press the two halves tight, while I crimped them back together. Made for a good tight seal and a secure fixture while I hammered away on the ring.

[budman]

You do nice work, Dave.

[eM3rge]

Hey Dave! I was just browsing around here and I think I have your old bike!

[Davez134]

Nice, haven't seen it in a while. Good to know someone is still enjoying it!

[eM3rge]

You're more than welcome to check it out, I'm at the southwest part of the valley.

[Davez134]

I'm in the southwest as well. We'll have to go ride soon.

[moraarcher]

Very impressed, what a beautiful bike. Just showed the pictures to my wife and said I'd like to something like that someday. She said it looked great and if that's what I wanted to do go ahead. That's my opening and now I'm on the hunt. I still have some things to finish on my '72 750.
Once again nice job on the bike and the write up.

[Davez134]

Very impressed, what a beautiful bike. Just showed the pictures to my wife and said I'd like to something like that someday. She said it looked great and if that's what I wanted to do go ahead. That's my opening and now I'm on the hunt. I still have some things to finish on my '72 750.
Once again nice job on the bike and the write up.

Thanks for the kind words! Glad I can give some inspiration, and facilitate the go-ahead from the boss

[Davez134]

So I'm getting some things done this winter while it's cold out. First of all, I was leaking oil past a couple valve seals. I replaced The seals, but the leak came back. Most likely because the bronze guides are worn. They are being replaced with cast iron guides, valve job, new seals. Second, against my better judgement, I am splitting the cases to replace the crankshaft seal in the points side that I put in backwards originally (big oops). Some pics to come soon.

As it sits right now (minus head, which has been sent out)

[SOHC4 Cafe Racer Fan]

That motor looks pretty clean.

[Davez134]

That motor looks pretty clean.

Yeah, I was pleased to see the cam was well oiled and things were nice and clean. The pistons however were caked with deposits, and oil was even in the valve relief of #1. My head is in good hands now wait that sounded weird.