Topic: Potential 1970 CB750 K0/K1 Hybrid

[newday777]

Red foam is back in stock now on Yamiya. It is $350 now plus $200 shipping to the US.

There are no other sources out there as far as I know.

Just dye the white foam red???

Can’t be too difficult.

It’s been on my list of things to figure out over the next few months.

The foam may start to break down from getting wet.

[BenelliSEI]

Red foam is back in stock now on Yamiya. It is $350 now plus $200 shipping to the US.

There are no other sources out there as far as I know.

Just dye the white foam red???

Can’t be too difficult.

It’s been on my list of things to figure out over the next few months.

Let me know how that goes…… I tried a few and failed miserably.

[jakec]

Red foam is back in stock now on Yamiya. It is $350 now plus $200 shipping to the US.

There are no other sources out there as far as I know.

Just dye the white foam red???

Can’t be too difficult.

It’s been on my list of things to figure out over the next few months.

I’d be fine with white foam in the correct shape but no one makes that either.

[grcamna2]

Red foam is back in stock now on Yamiya. It is $350 now plus $200 shipping to the US.

There are no other sources out there as far as I know.

Just dye the white foam red???

Can’t be too difficult.

It’s been on my list of things to figure out over the next few months.

I’d be fine with white foam in the correct shape but no one makes that either.

4into1 carry it?

[jakec]

I only see later style 1972-76

[MauiK3]

Waiting to hear what you find inside.

[Lucien Harpress]

The goal is to get the engine out this week.  I've pulled most, if not all of the stuff in the way (air box, carbs, oil tank).  I think today I'm going to get the frame wrapped to protect the paint.  I'm not looking forward to pulling it out sideways, but it is what it is.

I attempted to strain my used oil through a coffee filter- a good idea that didn't work.  Still, the bottom of the catch pan looked like  :)metallic paint, so I've got a couple good ideas of what I'm going to find.

[Kevin D]

I have used a paint filter and it works fairly well.

[Lucien Harpress]

I would love to say this gets easier.  That would be a lie, though.





Thankfully, I didn't scuff up the frame or engine too bad getting it out.  The bad news?  I've added to my list of things I need replaced unrelated to the engine.  My "stripped rear shock mount" was joined by "new coil" because I may have forgotten one plug wire still in the plug well of the engine when I pulled it.  The wire came with it, the coil stayed.

In any case, since I'm going back into this engine I'm thinking of doing a couple other things beyond correct crank bearings.  I'm VERY strongly considering getting my crank balanced.  The bike has always been on the buzzy side, to the point my hands got tingly on longer rides and my mirrors were mostly useless.  I was hoping a rebuild would help things, but my 15 minute post-rebuild ride showed that not to be the case.

Cycle-X keeps coming up as the place to go for this, and the rates seem quite reasonable.  The plan is to get the engine tore apart again, take a look at the actual damage and (depending on what that looks like) then shoot out some exploratory e-mails. 

[BenelliSEI]

…… Nice work. I feel your pain.

[denward17]

Good Luck Lucien...

[Don R]

 My "tight spot" engine turned out to be a scuffed cylinder it was scuffed low where I couldn't see it with the head off. The piston had a matching bad spot. Good luck with yours. I've used a shop vac with a piece of tubing and brake clean to clean the oil tank.
  Mythbusters proved that sucking up fumes and gas doesn't always turn a shop vac into a jet engine.

[Don R]

Red foam has been out of stock for more than a few months, I missed (cheaped) out on getting one before JT Marks passed away, Now I wish I had gotten two.

Don: have you tried contacting his newer JTMarks77 seller? I think it is his daughter (wife?), as I got a girl's name with thanks on my last order from there.

 I sent an email to JT's old address, I'll see if she replies or is still ordering from yamiya.

[grcamna2]

I would love to say this gets easier.  That would be a lie, though.





Thankfully, I didn't scuff up the frame or engine too bad getting it out.  The bad news?  I've added to my list of things I need replaced unrelated to the engine.  My "stripped rear shock mount" was joined by "new coil" because I may have forgotten one plug wire still in the plug well of the engine when I pulled it.  The wire came with it, the coil stayed.

In any case, since I'm going back into this engine I'm thinking of doing a couple other things beyond correct crank bearings.  I'm VERY strongly considering getting my crank balanced.  The bike has always been on the buzzy side, to the point my hands got tingly on longer rides and my mirrors were mostly useless.  I was hoping a rebuild would help things, but my 15 minute post-rebuild ride showed that not to be the case.

Cycle-X keeps coming up as the place to go for this, and the rates seem quite reasonable.  The plan is to get the engine tore apart again, take a look at the actual damage and (depending on what that looks like) then shoot out some exploratory e-mails.

Lucien,is that a KZ1300 in the foreground ?

[RAFster122s]

I would love to say this gets easier.  That would be a lie, though.





Thankfully, I didn't scuff up the frame or engine too bad getting it out.  The bad news?  I've added to my list of things I need replaced unrelated to the engine.  My "stripped rear shock mount" was joined by "new coil" because I may have forgotten one plug wire still in the plug well of the engine when I pulled it.  The wire came with it, the coil stayed.

In any case, since I'm going back into this engine I'm thinking of doing a couple other things beyond correct crank bearings.  I'm VERY strongly considering getting my crank balanced.  The bike has always been on the buzzy side, to the point my hands got tingly on longer rides and my mirrors were mostly useless.  I was hoping a rebuild would help things, but my 15 minute post-rebuild ride showed that not to be the case.

Cycle-X keeps coming up as the place to go for this, and the rates seem quite reasonable.  The plan is to get the engine tore apart again, take a look at the actual damage and (depending on what that looks like) then shoot out some exploratory e-mails. 

What about APE in California, they do crank work...

[Lucien Harpress]

Lucien,is that a KZ1300 in the foreground ?

Sure is!  Picked that up a couple of years ago, and let me tell you, it's been a journey ever since.  It started with a bent rod, and while I've got it running and down the road, it's never been consistent.  The plan was to knuckle down and finally iron it out this summer once my 750 was done, but then this engine fun started, so looks like it's getting pushed back.

Still, when it IS working it's an absolute hoot.

[Gamma]

I feel for you Lucien, following with interest👍

[Kevin D]

LH, it will be easier to reinstall your engine if you grind the top lips of the circled frame boss smooth with the barrel. Sorry, I used to have a photo of my own smoothed motor mount, but I’ll be darned if I can find it. It’s posted here somewhere in the dusty pages of SOHC4.
I’m pretty sure this is a Hondaman tip.

[denward17]

Here's a pic of that mod....

[grcamna2]

I can see that sharp edges make it tough to install the engine.

[Lucien Harpress]

Whelp, teardown has begun, and even though I just have the head off, I've got a feeling deeper in is not going to be good.



(THAT definitely wasn't there before...)



(Now this bit of schmutz MIGHT be remains of the old head gasket, but on the other hand it is on one of the oil feed studs, and the others look pretty clean)

I stopped at the bores, because they seem pretty stuck on the block, and I need to find a way to get them off without goobering the paint OR bending the fins.  Still, I'm curious what deeper inside is going to look like.  Not that I'm going to like it....

[RAFster122s]

That's no fun, finding that lurking beneath the covers...
If crank is beyond what you can polish out by hand, if any damage is there then APE or CycleX will have to rework your crank. Did the camshaft get lunched in the process?

Hope the rebuild isn't too awful.
Definitely gonna need to tear it down completely and understand what failed and why so you can address those issues. Then clean and clean some more to ensure the internals are spotless. Crank bearing are going to need to be flushed well to ensure no metal paste is lurking in the ball bearings and primary gear and starter clutch areas are clean. Cases will need to have all the passages flushed and chased to check for any metallic remnant from the failure.

[BenelliSEI]

Check out page 32 of my “Sandcast Found” project thread. My “bores” were really stuck to the cases and I made a cheap and easy puller with a bit of angle iron, a pair of threaded rods, and a 20” length of 2” X 8” lumber…….Worked a treat.

[Lucien Harpress]

That bore puller idea is fantastic, and I'm absolutely stealing some version of the idea.  Thanks for the head's up!

[BenelliSEI]

That bore puller idea is fantastic, and I'm absolutely stealing some version of the idea.  Thanks for the head's up!

It did work well and only took about an hour to “build”. The angle iron is actually a scrap piece of a cheap, folding bed frame a neighbour threw out! Good Luck.