Author Topic: "Mile High" CB350 Four project  (Read 32711 times)

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Offline sbeckman7

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Re: "Mile High" CB350 Four project
« Reply #25 on: March 14, 2016, 12:19:02 AM »
Good to hear!

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #26 on: June 09, 2016, 07:42:21 PM »
Finally an update since I've actually gotten some things done!  A couple of the key goodies came in: MotoGP Yosh-rep exhaust finally landed and looks nice, and Cognitomoto finished cooking me up a custom triple tree. I'm still deciding if I want to polish it, or powdercoat it, or leave the nice satin finish on it that it already has...

I sent my whole motor off to Nils at Restocycle, and couldn't be happier with his service and communication.  I judge folks by how they handle things when $hit hits the fan, and a minor snafu (likely caused by UPS...) was greeted with an immediate resolution.  He will have my business again and again because of it.  Pics to follow!

AAAANNNNNDDD I got word from my welder guy that he's finally got my tank all put back together, and he's only charging for about 1/3 of his time!  I'll pick it up sometime early next week.

Frame is mostly de-tabbed at this point but I still have some work to do before I send it out for blasting.  Question for you guys:  I feel like the grinding wheels that I've been using for this task are leaving a bit too much evidence in the frame tubes.  What is everyone's abrasive disk of choice for this to leave a reasonable smooth surface on the tube prior to powdercoat?

Now that everything is squeaky clean, I have now found that one of the spark plug holes has some pretty damaged threads.  The plug threads in just fine, but a lot of material is gone from the threads in the head and the plug is quite loose and even wobbly until it snugs up.  I'm afraid there isn't enough material left to torque down the plug and have it hold.  SOOOOO......Helicoil or find another head?
« Last Edit: June 10, 2016, 08:27:29 AM by Denver_Larry »
2005 RC51
1973 CB350F...project

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #27 on: June 09, 2016, 07:44:52 PM »
2005 RC51
1973 CB350F...project

Offline calj737

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Re: "Mile High" CB350 Four project
« Reply #28 on: June 10, 2016, 03:25:28 AM »
An air-driven angle grinder with green/red scotchbrite disc. And thats about it. The powder coater will blast your frame anyway, and the coating will obscure any minor defects. Besides, the shine from the powder coat will distract everyone from seeing any imperfections with its beauty!

Cases look gorgeous! You might sen your triples to Nils too for a similar finish-
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #29 on: June 10, 2016, 10:47:38 AM »
Yeah I think you're right.  Polishing or powder coating can always happen later if I want to change it.
2005 RC51
1973 CB350F...project

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #30 on: June 10, 2016, 11:53:04 AM »
Another question regarding reassembly:

In the shop manual it mentions to install the shift drum in the neutral position, but doesn't mention what that is.  I assume you can use the second hole on the clutch side of the drum shaft as a reference, but I just don't know which way to have it.

And input on the spark plug threads?
2005 RC51
1973 CB350F...project

Offline camelman

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Re: "Mile High" CB350 Four project
« Reply #31 on: June 10, 2016, 05:02:07 PM »
Nice work so far. A couple comments on things you've brought up.

When you grind tabs off the frame, a flexible disc will maintain the radius of the tube more easily than a hard disc. A hard disc can quickly leave flat spots on the frame which are noticeable.

It seems you're going to some serious lengths to customize that machine. If you're considering power improvements, then I really recommend boring the carb throats. The carbs on the 350f are bad choke points, but can be made to flow much more air by a competent machinist. Next up for power improvements on the 350f is the head (ports and possibly larger valves) and then exhaust. Rick Denoon at DenoonSP will work magic on your carbs if you're interested.

For your spark plug threads, I wouldn't recommend a helicoil unless you can find one with a tapered final winding. Otherwise you'll have a gap in the contact between the crush washer on the spark plug and where the end of the helicoil "coil" stops. That gap can be filled by doubling up on crush washers with one larger than the other, but that's a dodgy solution. Timesert makes a good spark plug repair kit that would offer a better sealing surface.

Please post pics of the weld on your tank. I've considered doing that myself, but the cost is prohibitive. It seems a seam welder would be a great way to weld those tanks up (I think that's how the factory did them), but they aren't common.

Camelman
1972 350f rider: sold
1972 350f/466f cafe: for sale
1977 CB400f cafe:sold
1975 CB400f rider: sold
1970 CB750 K0 complete bike: sold
2005 Triumph Sprint ST 1050 rider

We've got to cut it off... and then come down on rockets.  (quoted from: seven minutes of terror)

Offline Denver_Larry

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"Mile High" CB350 Four project
« Reply #32 on: June 10, 2016, 08:19:57 PM »
Thanks for the input, I'll get some pics of the tank posted as soon as I pick it up.


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2005 RC51
1973 CB350F...project

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #33 on: June 10, 2016, 08:45:54 PM »
Damn, those Timesert kits are no joke price wise! 
2005 RC51
1973 CB350F...project

Offline camelman

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Re: "Mile High" CB350 Four project
« Reply #34 on: June 10, 2016, 10:17:39 PM »
Keensert kits should be cheaper.
1972 350f rider: sold
1972 350f/466f cafe: for sale
1977 CB400f cafe:sold
1975 CB400f rider: sold
1970 CB750 K0 complete bike: sold
2005 Triumph Sprint ST 1050 rider

We've got to cut it off... and then come down on rockets.  (quoted from: seven minutes of terror)

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #35 on: June 15, 2016, 02:51:40 PM »
Today was a successful day in farming out work!  Dropped off the cylinders and head at the machine shop for boring, skimming, and valve work.  Then picked up my tank from my welder guy.  I think he did a decent enough job and the price was right for the time he spent on it.  Not show quality welds but they are getting filled and smoothed anyway.
2005 RC51
1973 CB350F...project

Offline calj737

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Re: "Mile High" CB350 Four project
« Reply #36 on: June 15, 2016, 03:34:13 PM »
Seam welding those tanks is a major PITA. Just fill it with gas ful to the top, and apply blue painters tape around the entire length of the tank to check for any leaks. If you find them, might be easiest to line the tank.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #37 on: June 15, 2016, 03:45:01 PM »
Was planning on lining the tank anyway since there was a decent amount of rust that I had to take care of while it was apart.  The filling and smoothing is just for cosmetics.  Any recommendations on a tank sealer?  I plan on staying away from the Kreem stuff...

Any experience with this?
http://www.caswellplating.com/epoxy-gas-tank-sealer/dragons-blood-gas-tank-sealer.html
« Last Edit: June 15, 2016, 03:53:09 PM by Denver_Larry »
2005 RC51
1973 CB350F...project

Offline calj737

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Re: "Mile High" CB350 Four project
« Reply #38 on: June 15, 2016, 04:06:22 PM »
I only use Caswell, but I use the clear formula.

If you grind in those welds, you could open a pinhole, so go easy. And if the skins were rusty when welded, I can almost guarantee air holes in the welds. Lining is probably required, and Caswell sells the best in my opinion.
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #39 on: June 15, 2016, 04:13:02 PM »
Cool, I'll look for the clear stuff since I'm not to excited about a real visible coating inside.  I'm planning on just knowing off the high spots a little and then filling/priming. 
2005 RC51
1973 CB350F...project

Offline nvr2old

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Re: "Mile High" CB350 Four project
« Reply #40 on: June 15, 2016, 05:14:59 PM »
You might also consider taking your tank to a radiator repair shop.  They can do a leak down test and point out exactly where there might be even a tiny pin hole, if any.  I've done that with great success.  They also have a sealer for radiators that works nicely on gas tanks, too.  Kills 2 birds with one stone.
'76 CB550F-'72 XL250-'82 MB5-'82 CX500 Turbo-'77 naked Goldwing-'75 CB400F cafe'-'79 Suzuki GS1000S..hey, it's a Wes Cooley..

Offline NobleHops

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Re: "Mile High" CB350 Four project
« Reply #41 on: June 15, 2016, 06:56:08 PM »
Thank you for the good words Larry, you were a total pleasure to work with. Still annoyed that UPS managed to pierce my double-walled box!

Project is looking awesome.
Nils Menten * Tucson, Arizona, USA

I have a motorcycle problem.

My build thread: NobleHops makes a 400F pretty for his wife: http://forums.sohc4.net/index.php?topic=131210.0

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #42 on: July 03, 2016, 01:44:23 PM »
Decided to man up and get some polishing done.  Was thinking of having a professional handle the chores but after attacking a clip on with some heavy duty emery paper and working my way up with grit, the actual buffing stage went very easily.  These were stock CBR600RR clipons after grinding the locating nubs and casting marks off followed by some bead blasting:


One down, one to go:
2005 RC51
1973 CB350F...project

Offline Denver_Larry

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Re: "Mile High" CB350 Four project
« Reply #43 on: July 07, 2016, 04:40:00 PM »
Alright so who wants to give me the bad news and confirm them at I need to split the cases again to drop this thing in there?....  Any alternatives/tricks?
2005 RC51
1973 CB350F...project

Offline NobleHops

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Re: "Mile High" CB350 Four project
« Reply #44 on: July 08, 2016, 12:22:57 PM »
Alright so who wants to give me the bad news and confirm them at I need to split the cases again to drop this thing in there?....  Any alternatives/tricks?


Maybe not Larry - that kind-of looks like the business end of the cam chain tensioner. I wonder if you could install it from the top of the cylinders, with the head off?
Nils Menten * Tucson, Arizona, USA

I have a motorcycle problem.

My build thread: NobleHops makes a 400F pretty for his wife: http://forums.sohc4.net/index.php?topic=131210.0

Offline Denver_Larry

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Re: "Mile High" CB350 Four project **SOS!**
« Reply #45 on: July 08, 2016, 12:37:20 PM »
Oh that's for sure what it is!  I suppose that might be possible, I'll see if I can manage to get my big mitts down there...
Does anyone happen to have a picture of the inside of the case there since I will be doing it by feel?
2005 RC51
1973 CB350F...project

Offline NobleHops

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Re: "Mile High" CB350 Four project **SOS!**
« Reply #46 on: July 08, 2016, 01:25:32 PM »
I do not, but I bet MoMo does. Or could take one.
Nils Menten * Tucson, Arizona, USA

I have a motorcycle problem.

My build thread: NobleHops makes a 400F pretty for his wife: http://forums.sohc4.net/index.php?topic=131210.0

Offline NobleHops

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Re: "Mile High" CB350 Four project **SOS!**
« Reply #47 on: July 08, 2016, 01:26:20 PM »
Hey, where'd ya get those case bolts? Is that part of a Stainless Cycle set?
Nils Menten * Tucson, Arizona, USA

I have a motorcycle problem.

My build thread: NobleHops makes a 400F pretty for his wife: http://forums.sohc4.net/index.php?topic=131210.0

Offline calj737

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Re: "Mile High" CB350 Four project **SOS!**
« Reply #48 on: July 08, 2016, 01:27:01 PM »
Check out iiAtlas' build thread. He and a couple of other folks are rebuilding 350s right now...
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"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline Denver_Larry

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Re: "Mile High" CB350 Four project **SOS!**
« Reply #49 on: July 08, 2016, 01:29:51 PM »
Hey, where'd ya get those case bolts? Is that part of a Stainless Cycle set?
www.alloyboltz.com

Their case set was pretty complete, just didn't include oil pan bolts.  They carry ARP stuff as well.
2005 RC51
1973 CB350F...project