Author Topic: Hello from Houston (Read 2255 times)

77379 · « **on:** October 12, 2016, 04:40:35 PM »

Hello all, I am a fairly new owner of a couple of cb750s. The first one, a 1971 I got about a year ago. It's a good running bike but it could use some work. While looking for some parts on Craigslist I came across a 1969. I picked that one up and that is where I am going to start. It's in rough shape but the frame and cases look good. So I started the tear down. I'm going to take it slow because my free time is limited like everybody else. After freeing up the stuck pistons in already oversized sleeves, I discovered a crack in one sleeve. Because I want to eventually rebuild the bike back to original, I am going to resleeve the cylinders. I searched for some new sleeves and found some at LA Sleeve. Their reference materials only go as far back as 1973 for the cb750. I'm pretty sure but not positive that a 1969 sleeve would be the same as a 1973 sleeve. Would any of you all know for certain if they are the same? I know I'll have a lot more questions along the way but I'll start with this and again hello to you all.

Stev-o · « **Reply #1 on:** October 12, 2016, 05:09:38 PM »

Welcome from Lake Travis. Guessing you are in the Spring area?

Yes, the '73 sleeve will fit your cylinder.

If you have nothing to do next weekend, there is a great annual vintage bike show in Luckenbach...

http://www.harvestclassic.org/activities/

77379 · « **Reply #2 on:** October 12, 2016, 06:01:18 PM »

Yes, I'm in Spring Stev-o and thanks for the warm welcome. It will be a great weekend to be in Luckenback but I already have some plans. Looks like fun, enjoy it.
Thanks for the confirmation on the sleeve also. I've got it ordered along with new pistons and rings.
It's on to sanding down that valve cover while I'm waiting for FedEx.

rocket johnny · « **Reply #3 on:** October 12, 2016, 07:59:47 PM »

welcome from western colorado ! see some pics of your bike ??

77379 · « **Reply #4 on:** October 13, 2016, 05:08:20 PM »

I'll try this again. My post with the pictures didn't seem to post before

scottly · « **Reply #5 on:** October 13, 2016, 08:31:50 PM »

Welcome! What are the serial numbers on the frame and engine?

77379 · « **Reply #6 on:** October 14, 2016, 01:45:24 PM »

Thanks for the welcome scottly, it's engine 1770 and frame 1639. I wasn't able to take great pictures because I have too much stuff all crammed into a little space. My better half told me I need another project like I need a hole in the head but I'm looking forward to this one.

calj737 · « **Reply #7 on:** October 14, 2016, 02:09:51 PM »

If you strip that motor down, and the carbs, send them off to Noblehops (member here, Nils is his real name) to be vapor blasted. That will restore them to an uncanny finish.

http://forums.sohc4.net/index.php/topic,150819.0.html

77379 · « **Reply #8 on:** October 14, 2016, 02:37:21 PM »

Thanks for pointing me in the right direction calj737. I read through the link you sent and his work looks fantastic. There are plenty of positive testimonials commending Nils' work. Your advice is exactly the kind of information I was looking for. Thanks again.
Gregg

Stev-o · « **Reply #9 on:** October 14, 2016, 03:42:09 PM »

+ 1 on Nils' vapor blasting, fantastic work and service. I sent him a Kawasaki H2 motor as well as the rearsets on my current project.

scottly · « **Reply #10 on:** October 14, 2016, 05:27:50 PM »

I'm not sure if it would be wise to vapor blast a SANDCAST motor.

calj737 · « **Reply #11 on:** October 14, 2016, 06:06:05 PM »

Quote from: scottly on October 14, 2016, 05:27:50 PM

I'm not sure if it would be wise to vapor blast a SANDCAST motor.

And you think this why? Vapor blasting is completely non-destructive and removes grease, oxidization, and safe enough to apply to gasket, machined, mating surfaces.

scottly · « **Reply #12 on:** October 14, 2016, 06:16:53 PM »

Quote from: calj737 on October 14, 2016, 02:09:51 PM

That will restore them to an uncanny finish.

You don't want an uncanny finish on a Sandy, you want it to look original.

Gregg, do you know what you have there? It's the holy grail of SOHC fours. Only the first 7300 or so 750's were sandcast. Is there any damage in the engine case in front of the sprocket?

danyo · « **Reply #13 on:** October 14, 2016, 06:52:44 PM »

Another sandcast found! Congratulations on your score. I can see smooth oil filter housing. Don't throw away any parts, lot of them very hard to replace.

Sent from my SM-N900T using Tapatalk

scottly · « **Reply #14 on:** October 14, 2016, 06:59:19 PM »

Good eye, Danyo; I missed the oil filter housing. The giveaway for me was the shape of the serial number pad; that's why I asked about the numbers.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #15 on:** October 14, 2016, 08:54:30 PM »

Get in touch with KMB69. He's in Houston and may have some good advice.

70CB750 · « **Reply #16 on:** October 15, 2016, 03:37:26 AM »

Welcome!

calj737 · « **Reply #17 on:** October 15, 2016, 04:06:59 AM »

Quote from: scottly on October 14, 2016, 06:16:53 PM

You don't want an uncanny finish on a Sandy, you want it to look original.

Perhaps if the bike were worthy of a "Survivor/Original" condition, that would be prudent. Given its condition, and the modifications made by prior owners, the route I'd take is to restore the bike to a high standard. VB is used on Concours level restorations very commonly as it produces the best, least destructive result to aluminum. Period. Besides, how else do you comprehensively recover the neglected aluminum? Sand and buff it? Then you end polishing it, which is certainly not "good".

Whether or not the OP fancies it, well thats up to him. I was merely providing him links to resources to aide him in determining a path to his objective.

77379 · « **Reply #18 on:** October 15, 2016, 01:32:38 PM »

I think my last post didn't post again for some reason but I'll repost the pictures to answer some questions
Gregg

77379 · « **Reply #19 on:** October 15, 2016, 01:47:07 PM »

Ok in my lost post I tried to answer some questions and explain my goals. I learned about the sandcasts about a year ago when I was looking for a vintage CB750. I do realize that this bike has the potential to be a nice bike and I plan to put it back together in as close to its original form as I can. I like the idea of the vapor blasting because as I was sanding away at some of the covers I knew there had to be a better way. I wish I had some pictures of the before. I posted one of the covers that I have been working on but is not complete yet. I also have a picture of the cylinders that show the date code at the bottom of 41H, which I believe is August 1, 1969. I also showed the worst of the damage on the fins and where the top and bottom case bolt together. Again I appreciate the welcome, the advice and interest in my pending project.
Gregg

calj737 · « **Reply #20 on:** October 15, 2016, 03:52:06 PM »

Gregg - you may enjoy reading this thread. A member here has done as accurate a sandcastle restoration as can be found by mere mortals.
http://forums.sohc4.net/index.php/topic,79183.0.html

There's also a completely separate Sandcast Forum you can join:
http://www.cb750sandcastonly.com

77379 · « **Reply #21 on:** October 15, 2016, 05:53:54 PM »

Yes calj737, I read through markb's restoration of #97 start to finish - twice. He truly did beautiful work on that bike. His work is very inspiring. At this point I know I don't have the skills to do the high level of restoration that he did. He set the bar very high. I contacted him about a few questions that I had and he was also very generous with his advice and very helpful.
I also saw the sandcast forum. Some of the members there are high level experts about the sandcast version of the CB750. From what I read on their forum, they are having conversations among experts. I appreciate their expertise and their appreciation of 750s. I will be the first to admit that I am no expert. I know that I don't have the expertise to make a worthwhile contribution to their discussions. I have also dealt with some other active members from their site in my quest to acquire parts and have had nothing but positive experiences with them. From my limited experience here, I have enjoyed the welcoming, the interest and the willingness of previous strangers to point me in the right direction.
Gregg

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Author Topic: Hello from Houston (Read 2255 times)