Topic: 1973 CB750 Four K3 -- Project "Terry's Fault" -- BUILD RESUMED

[Bill/BentON Racing]

Rafi, I've got some sprocket carriers if interested, Bill

[SOHC4 Cafe Racer Fan]

Woohoo. I have it on good information that this project and thread is being resurrected into active status.

[Stev-o]

Woohoo. I have it on good information that this project and thread is being resurrected into active status.

Pics or it aint happening!

[edwardmorris]

Haha, thanks for the bump Don. Yes, its winter and there are bound to be some days I'm stuck at home because of snow and will be needing to do some wrenching to keep busy No pix of any major progress yet Stev-o but I do have some to report. Early this year, the K2 and K3 builds were running in parallel until it warmed up and I was totally focused on the K2. Got that done, dialed it in, and just kept logging miles as I made time.

So last when we left off, I had the frame out at the welder's for installing the GFK. After cutting the frame, I did my usual Eastwood Internal Frame coating, drilled out the missing "quiet memo" holes, cut off the nasty welded on foot pegs and grab rail mounts. Frame is back with the kit installed and ready for PC.

Swingarm went to Mark/Hondaman and has returned with a new life. From the pix earlier in the thread, you can tell the swingarm collar was toast, so Mark made me a custom one matched up to the newly installed bushings, good stuff! Also ready for PC.

I had the center stand shortened for the K3 too, but as I learned during the K2 assembly, this simply doesn't work for the 18" rear wheels. So, I now have two shortened center stands, one PC'd and one bare that I can't use. These may work well for those who go with 17" or 16" (what the K3 came with) rears, so PM me if you need one of them. Another center stand has been added to my list for Santa!

Kick stand has been elongated just a little. This has worked out really well on the K2 (eventhough I do have the stock size one for it), so I'm keeping it elongated for the K3 as well.

Most of the missing bits came from Billy B some time in March, but I can't find them for the life of me. I've gotta clean up shop box by box as I'm missing many critical bits.

Found me a good sprocket carrier for like $9 on ebay, total fluke.

Engine obviously is all blasted and stripped, but needs a compulsive clean. The K3 head has small fin damage that I couldn't find any local guys to fix. A replacement K3 head is on its way from Billy and this one is going to Mark/Hondaman for one of his builds.

Right now, I'm just boxing up stuff to get to the powder coaters, hoping to save some $$ off-season.



The one thing that worries me a little about this build (even more so now after the K2 BOTY win) is that it is going to disappoint many. It isn't even in the same galaxy as a stock build, but its not going to be cafe/chop/punk. I'd call it a pro-stock build as it will retain some of the stock look with beefed up internals. I wanted to build this to be purely my own, and its based on one of my fav vid game beasts (I know, super lame). I almost got booed off of here when someone mistook a gold shine to be rust on the K2  . When they see this one I fear the worst

[SOHC4 Cafe Racer Fan]

Not every build needs to be at a concourse level or even close. Just build what you like. We will still be here.

[edwardmorris]

Not every build needs to be at a concourse level or even close. Just build what you like. We will still be here.

Haha, thanks Don! On that note, any tips on cutting up the front fender? I'm going for a smaller arc than stock...

[Terry in Australia]

Good to see this thread "back on the road" Rafi, keep up the good work, and enjoy your build. Cheers, Terry.

[SOHC4 Cafe Racer Fan]

Not every build needs to be at a concourse level or even close. Just build what you like. We will still be here.

Haha, thanks Don! On that note, any tips on cutting up the front fender? I'm going for a smaller arc than stock...

Use a masking (painter's) tape on the cutting area and draw/pen out your arc.  Use a new cutting wheel and go at it. 

[edwardmorris]

Thanks Don, I can't find my angle grinder. I think the wife hid it because she thinks its a flame thrower that will burn down the garage  :o . I did some digging to see if I could use a hacksaw and found this

http://forums.sohc4.net/index.php/topic,91026.msg1017788.html#msg1017788   (Cool shot of Phaedrus 1).

So I did that, then marked the rounded ends using the cut-offs, then free-hand dremel cut. Came out OK I think, need to go over to the in-laws over the weekend to grind it down smooth.

Took the forks to the local auto shop and borrowed their 3/8" air impact with and allen style socket to knock loose the bottom bolts. Took them apart at home and found there wasn't a copper crush washer on either of the bolts, but the drain bolts on the side did have them. Whatever drained out of there wasn't oil, and stunk like sewage. Took off the circlips and put the lowers through the parts washer (ahhh! that sweet smell of simple green  ) then rinsed them off with hot water. Left them in the hot water for a while then removed the seals fairly easily. The sealing surface looks ok, so these are good to go. Will need new tubes though.


Everything is ready to go to the powder shop, but I'm missing a center stand. Hopefully Bill can get it out soon Will be attempting to remove the cylinder-case studs over the weekend, have them soaking in penetrating oil for now. Gave them all a good tap on the head, will do the usual double nut with vice-grip at the bottom and heat.

[tweakin]

Build the bike for yourself not to please the forum and you cant go wrong.  Looking forward to following along.

The one thing that worries me a little about this build (even more so now after the K2 BOTY win) is that it is going to disappoint many. It isn't even in the same galaxy as a stock build, but its not going to be cafe/chop/punk. I'd call it a pro-stock build as it will retain some of the stock look with beefed up internals. I wanted to build this to be purely my own, and its based on one of my fav vid game beasts (I know, super lame). I almost got booed off of here when someone mistook a gold shine to be rust on the K2  . When they see this one I fear the worst

[edwardmorris]

Haha, thanks Tige. (I'm just kidding btw if anyone missed it ) This will be more like one of yours or Branden's 836s minus the high-end stuff (CRs/Motogp/BackcutTrans..etc.). I know its been a while Tige, but your pointers on the LED back-lit gauges were awesome! They turned out just like I wanted them! All that is left on them is to solder up some old school connectors to wire them up with the harness.

Haven't done much yet today except for clean up the garage a little to reclaims some workspace. Ended up with yet another bag of Honda part wrappers that fell through the cracks during the K2 assembly These things just have wayyy too many bits and bobs 

Build the bike for yourself not to please the forum and you cant go wrong.  Looking forward to following along.

The one thing that worries me a little about this build (even more so now after the K2 BOTY win) is that it is going to disappoint many. It isn't even in the same galaxy as a stock build, but its not going to be cafe/chop/punk. I'd call it a pro-stock build as it will retain some of the stock look with beefed up internals. I wanted to build this to be purely my own, and its based on one of my fav vid game beasts (I know, super lame). I almost got booed off of here when someone mistook a gold shine to be rust on the K2  . When they see this one I fear the worst

[edwardmorris]

Got the studs out last night but couldn't post pix. Pretty much all survivors except for the outer front two exposed to the elements. Those were corroded and bent a little when twisting loose. Thankfully no harm to the gasket area anywhere except for the stinky mess PB blaster made. Time to clean clean clean it all up and prep for PC. Replacement head should be here any day now.

[edwardmorris]

if you are having it powder coated, it doesn't really need to be that clean. A pro will prep it well beforehand.

I am that "pro" for this one, I'm doing all the initial cleaning and taping/masking as I don't trust anyone but Bob (main guy a the shop) doing it. He's too busy but told me he'd let me use his supplies, then review it after I brought it back masked up. I sorta insisted he does the engine himself. The rest of it, I trust his staff, they did ok with the K2 except for butchering the VIN plate for which Bob has apologized and expressed regret.

[edwardmorris]

Hoping to get more stuff done and prepped this weekend, but lets get another discussion out of the way shall we?

Engine: I no longer have the patience to re-plate all hardware nor the money to replace it with all NOS stuff. Any cause for concern going all stainless throughout? I know that the super long 120mm and 140mm main bearing ones will not be easy to find but I plan on using APE HD main bearing studs anyway so not an issue. Rest of the sizes seem readily available. Two minor concerns I can think of are slimmer nuts (like front suspension) and small OD washers (OE ones have two part numbers for 8mm bolt washers).

Good news with the main bearing studs is that the newest batch from APE are a few mm longer so the issue of them being a little short is addressed. However I haven't yet received confirmation of the same issue being resolved for the cylinder studs. Anyone have any trouble in recent times with the HD cyl studs being too short?

[Stev-o]

I typically use ss hardware when replacing old hardware.  I see it as an upgrade.

Unless your rebuilding a NOS bike, which I havent.

[Restoration Fan]

Oh boy.  SO very in for this one.

Looking forward to it, Edward.

One piece of advice that slightly echos what others have said.  Don't worry about a concourse level restoration, or even a BOTM candidate restoration.  Every one of us rejoices when a single one of these old SOHC's is put back on the road again.

[edwardmorris]

Thanks Stev-o. Ron, yes this is going to be mine, something that won't need a lot of upkeep and is more fun. lol its early enough, lower your expectations on this one now, folks 


OK, so some searching around and looks like SS in Alloy is quite the debate, one even spun into a torquing technique debate  SS it is, gotta dig out my hardware sheet. No luck on the studs concern though 

Goodies from Bill arrived, was waiting on the center stand to get the frame+h/w sent off to PC. The replacement head is here, cleaned out some casting flash between the fins (very little on the early ones). Gotta do the same for the cylinders and wrap it up. Going through my list, bearing removal is next, not fun but needs to be done . Lesters are getting coated too!

[edwardmorris]

I already have a set of stainless screws made by James Spillane for the covers and I think I have just about located all the bolts except for the two odd ball fat ones.

Anyway, skipped the bearing pulling for today but I did finish the modification on the tail light bracket. That was the last piece holding up a drop off at the chromer. He's gonna look at me funny when he sees that I have a tiny box this time around Sorry about just posting boring text replies, doing things the second time around I'm not terrified of ruining something so I've been pretty lazy with taking pix. I'll definitely do better during assembly 

[edwardmorris]

So some progress today, unfortunately no before pix. The swingarm has new bushings and collar from Mark, but pretty much all the tabs on it were butchered by the PO. There was a wiiiide 16" rear that probably didn't work well with the rear brake panel and stay, so not only was the stay rod bent outta shape, but the PO had bolted it on from the outside of the brackets in pic 1, then tightened it down till they crushed together, then he bent it to match the bent stay rod . Took some work on my trusty bench vice and straightened it out.

Next big fail was the end cap threaded holes. During disassembly, I found that he had forced through some poor grade SAE size bolts through the 8mmx1.25 threads  . As sihtty as that is, since he cheaped out, the threads weren't fully gone on the swingarm (tough steel). Thread chasers didn't quite cut it, so I had to use a tap with tons of lube to fix them. Tested, we're good to go there.

Next up were the upper tabs that were butchered to install a gungho chain guard. I just don't get why did he have to drill a fat-ass hole through a 6mm nut ? And to make it worse, it was cock-eyed  . Even the 8mm tap was slipping right through so I went up to the next size without looking. Now this one has a 9mmx1.25 thread on it, no idea if there's a bolt that size easily available. I don't want to tap it out to 10mm so looking for ideas here, will an 8mm helicoil do the trick? Heck, even 8mm is too large, would ideally like to bring it back to 6mm.

[edwardmorris]

Well, got to the first of the five wheel bearings today. Warmed it up with the heat gun and knocked it outta there. The metal sealed bearing, meaning someone had changed it once before. The retainer was a bit tricky to get out as there are some banged up threads (upper most) on the retainer itself, but thankfully the carrier side is ok. Ran a tap and cleaned it out even more, but will need to find a better retainer+seal for sure, not worth risking with banged up threads. This, and cleaned up a bunch more parts, little progress during the work week.

[edwardmorris]

Debating if I should use this or stick with the stocker. This goes better with the Lesters IMO, but there is a tiny gap, not sure how big an issue that is. Thoughts?

[edwardmorris]

Some findings.

[enwri]

Or maybe,

[754]

I look at it this way.. Some guys drill holes in their backing plates.. Unless you ride a lot on dirt roads, dirt coming in is not an issue.. Water maybe , i would be careful at a carwash or after washing...

 But I often wondered, sometimes there is a lot of brake dust when removing wheel..and I dont think it helps braking.. But if its ventilated, or air can get in....maybe that dust will blow out..

[edwardmorris]

So what do you think about using a large gasket/o-ring on it to maybe partially seal it up? Moisture getting in there would be a concern. Any other ideas?