Author Topic: 1975 CB750 Build! "Kona" - Sold and gone. (Read 71238 times)

Ravie · « **Reply #75 on:** July 23, 2014, 08:02:50 PM »

One of them's got a decent scratch in it and I do see some wear in the top ones especially. The bottom ones are not so bad, oddly. Could I just replace the top halves?

Ravie · « **Reply #76 on:** July 23, 2014, 08:25:04 PM »

yeah, I probably will. Cost isn't really a big factor - it will only lengthen the amount of time it takes for the rebuild as a function of how much money I can spend and when... I'll be sad if I can't finish it before the riding season is kaput...but at the same time I want to do it right the first time around, so I'm not in a hurry either. Rather do it right than quick.

Best (cheapest) place to get new primary chains? I'm getting a fair amount of stuff from DCC and Vintagecb750.com. not sure if DCC has it (haven't looked)

Tews19 · « **Reply #77 on:** July 24, 2014, 09:27:05 PM »

The horn sounds like this.

Watch "The Most Annoying Sound In The World" on YouTube
The Most Annoying Sound In The World: http://youtu.be/0cVlTeIATBs

Ravie · « **Reply #78 on:** July 25, 2014, 09:48:13 AM »

This may not belong here but I thought I'd share this anyway, as it pertains to this thread..

Got my walking papers today.

Just started working for this company three months ago who has been keeping my resume for a year because the general manager liked it. They finally hire me only to have one of their major contracts have issues causing them to lay off a bunch of guys, myself included.

So That's gonna slow down the bike project for sure. I still have quite a bit I can do as far as cleaning/painting goes but parts purchases will be at a stand-still until I can become gainfully employed again.

I did manage to clean up the fenders and spray them just now. I'd sand-blasted them a while back to prep them for being painted and decided to hit them with Rustoleum truck bed liner. Looks good so far. had one goof on the rear fender but I think I got it covered okay.

Rav

Tews19 · « **Reply #79 on:** July 25, 2014, 09:54:08 AM »

That sucks bud but hang in there. Are you missing any parts? I can check my stash or you can see my for sale thread. If I have anything you may be able to use let me know. I send as to you for free to help the build continue. I could check the K0 engine lower I have for any internals you may need.

Ravie · « **Reply #80 on:** July 25, 2014, 10:34:23 AM »

Thanks Tews. I'm not sure. I think I've got just about everything I need that I don't need to buy new. The wiring harnesses in both bikes were in terrible shape so I was just going to buy a new stock one at some point. Same thing for most of the electrics..they looked pretty nasty, some of them.

As far as engine parts go, it's complete except for the pistons which I am going to replace as the originals were quite worn, most likely the crank bearings, seals, and sprocket (I need a new chain and was advised probably back at page 1 that I need to replace the sprockets as well as the chain)

Thanks again, and I'll let you know if I come across anything.

SOHC4 Cafe Racer Fan · « **Reply #81 on:** July 25, 2014, 05:31:42 PM »

That totally sucks. Hope you find a new gig soon in the interim, let us know what we can help you with on this build or otherwise.

Ravie · « **Reply #82 on:** July 25, 2014, 07:59:26 PM »

You guys are good dudes. Thanks. I've got some unemployment I can draw on for a while, so that helps.

I need to spend the morning cleaning the garage tomorrow. Amazing how something as small as a bike can create such a huge mess. I need to organize my parts piles better. I've been bagging, labeling and then throwing everything into a big pile.

Now that my money flow is changing I'm rethinking some of my plans. The bearings checked out tight and while a couple of the uppers have some side wear, I don't think they would be a danger if I ran them. I really think the primary chains look tight too. Maybe I'll do a vid and get your opinion. I could just do a bore/hone/new pistons/rings and leave the bottom end be except for a new cam chain and tensioner. The transmission components all look great, too.

Tews19 · « **Reply #83 on:** July 25, 2014, 08:13:34 PM »

On my 550 build I'm doing right now I left everything on the lower end the same. My buddy who is a former mechanic checked it all out and said I was good to go. Of course I changed the seals. The top end is a different story. Big bore in a small engine.

Tews19 · « **Reply #84 on:** July 26, 2014, 07:39:02 AM »

Nope. I read if I recall from bwaller or Ape that it was somewhat overkill on the 550. I may be lucky to gain a few HP with this build with the minimal work I did.

Ravie · « **Reply #85 on:** July 26, 2014, 09:16:45 AM »

No problem!

Is there any HP difference to go multiple oversizes up if you did nothing else to the engine?

Ravie · « **Reply #86 on:** July 26, 2014, 11:25:11 AM »

That's pretty much what I was thinking. Are there any examples of the best places to "help" head flow around? Maybe some pictures or videos?

SOHC4 Cafe Racer Fan · « **Reply #87 on:** July 26, 2014, 03:12:11 PM »

Quote from: calj737 on July 26, 2014, 11:40:06 AM

Here's some pictures from the best guy around, Mike Rieck. This is my 500 head he did a Stage 3 job on. Intakes and exhausts, plus manifolds pictured:

Magnificent. I think even MR would tell you that it's not solely about widening the ports but getting optimal shape. That's where there is an art to porting to optimize flow.

Tews19 · « **Reply #88 on:** July 26, 2014, 03:36:06 PM »

Quote from: calj737 on July 26, 2014, 07:58:41 AM

Sorry for the hijack...

Just a big bore kit? No Stage 3 or big cam? If not, then yup, stock is good. But if... MRieck told me I'd be very smart to install them with the work on my 500. I got APE studs and ARP nuts.

650 cam and I think stage 2 head work. ...

Ravie · « **Reply #89 on:** July 26, 2014, 08:02:01 PM »

Hey guys. I had a bunch of little things I wanted to talk about so I just went ahead and made a video for you.

https://www.youtube.com/watch?v=R-ti1IDkVZg

Tews19 · « **Reply #90 on:** July 27, 2014, 06:10:13 AM »

Ravie we just got home. The 360 tank is funky on my 750. I'd say it doesn't work on a 750.

Ravie · « **Reply #91 on:** July 27, 2014, 06:40:46 AM »

^ Cool Tews. Thanks. I'll go ahead with the CX tank.

Ravie · « **Reply #92 on:** July 27, 2014, 02:17:37 PM »

I haven't seen any replies to my vid here yet, so I'm guessing you haven't yet seen my mess...but it was BAD. Spent nearly half the day today cleaning the garage. Trying to clean the built up tar and oil and guck from the inside of my chain guard. Both are just as bad as one another...i've got it soaking and every 20 minutes I go scrub some more...

I went scratching up the rear light bar with rough grade steel wool hoping I could score it enough for paint...but it kept getting shinier...haha So I kept going with successive grades and now it's shiny! I guess the bike will have some shiny parts after all... But not many, darnit! This ain't no show queen!

I've been really thinking hard about my plans going forward. When I still had a full time job I was planning to get the frame blasted and powdercoated and stuff, but now that I'm looking at it with fresh eyes I'm thinking of other options. It's not in terrible shape. I could likely clean up some rusty spots and hit it with either Rustoleum or POR-15.

I may make another video before too long with more thoughts and questions. I'm hoping a few of you will give me your opinions on some of the things from the vid a few posts above ^

edwardmorris · « **Reply #93 on:** July 27, 2014, 03:07:28 PM »

I saw the vid but I can't recall all the questions. I do know you were wondering about ultrasonically cleaning the carbs, I can tell you it works well if you have one, I had a loaner so I did mine that way, came out nice

http://forums.sohc4.net/index.php?topic=126735.msg1542350#msg1542350.

Ravie · « **Reply #94 on:** July 27, 2014, 03:55:07 PM »

I saw a cool write-up on cleaning them using a home-made soda-blaster, too. I bought the hose for it... you essentially use a small clear hose and cut a slit and put your air hose in it and tape it on and it creates a venturi that will suck baking soda right out of the box. I need to get a new belt for my compressor tomorrow and then plan to try it.

I've got a thing of carb cleaner I plan to dip them in, as well. If I can't buy parts I can at least clean what i've got so it's ready for re-assembly.

One of the questions I had was about the coils. I've got two TEC coils (and TEC points...should I clean the contacts and try to use them?) and I'm curious if I should see if one works and how I might about testing them. I know that can be difficult to do.

mrbreeze · « **Reply #95 on:** July 27, 2014, 05:18:05 PM »

I use an old chevy points distributor for checking coils. That......a battery charger (or a charged car battery), and a vise. Just wire it up the way the way you would in the car using which ever coil you want to test.

edwardmorris · « **Reply #96 on:** July 27, 2014, 05:24:25 PM »

Soda blasting is good for the carb bodies, but you may still need to US clean the jets and such to get the gunk (if any) out of the small passages. As for the carb dip, I was advised to stay away from it if you don't want to lose the factory iridescent finish on the bodies.

Ravie · « **Reply #97 on:** July 27, 2014, 06:49:52 PM »

Too late! haha. So far it looks like all I'm going to need are bowl gaskets and fuel share-pipe o-rings(just came up with that name myself.). The first two I have taken apart were OK. Floats look good, etc. I finally figured out where the ID stamp is. 657B's. 105/40 jets. 2.0 on the inlet.

Ravie · « **Reply #98 on:** August 01, 2014, 07:53:37 AM »

Prepped and sprayed the frame and swingarm yesterday. Several coats of spray bomb rustoleum flat black and hot sun to help cure it.

836 big bore the plan, as it will actually cost less. That'll be neat. I have some experience porting aluminum heads so ill do some light work in the head.

Obligatory pics.

Sent from my HTC One V using Tapatalk

Ravie · « **Reply #99 on:** August 01, 2014, 11:56:00 AM »

I suppose I could set it up and put a heater on high below it for a couple hours...

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Author Topic: 1975 CB750 Build! "Kona" - Sold and gone. (Read 71238 times)