Author Topic: 1973 CB350F "Modest Original" build  (Read 101508 times)

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Offline SOHC4 Cafe Racer Fan

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Re: 1973 CB350F "Modest Original" build
« Reply #600 on: February 02, 2017, 06:13:25 PM »
I think the CL350 may do like 90(not 150  :D) in 5th.. w/ it's larger(than a CB) stock rear sprocket;it would be interesting to know how it runs up there at redline in 5th w/ that ignition work,etc. you did to it.



C'mon man, Bill, you know in can do 80 in second, 110 third, 130 fourth and 150 in fifth.   Ask The WildeOne, he'll vouch for it

Did that former member 'Wilde' really think that his CB350F could do 80 in 2nd ?  :o :D

Actually, I believe he claimed 85 mph in 2nd gear.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline grcamna2

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Re: 1973 CB350F "Modest Original" build
« Reply #601 on: February 02, 2017, 06:32:34 PM »
Must've been running nitrous..  ::) through his oxygen mask.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline MoMo

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Re: 1973 CB350F "Modest Original" build
« Reply #602 on: February 02, 2017, 09:05:30 PM »
I think the CL350 may do like 90(not 150  :D) in 5th.. w/ it's larger(than a CB) stock rear sprocket;it would be interesting to know how it runs up there at redline in 5th w/ that ignition work,etc. you did to it.



C'mon man, Bill, you know in can do 80 in second, 110 third, 130 fourth and 150 in fifth.   Ask The WildeOne, he'll vouch for it

Did that former member 'Wilde' really think that his CB350F could do 80 in 2nd ?  :o :D

Actually, I believe he claimed 85 mph in 2nd gear.



My bad (one of those horrible hip phrases I despise). You're correct, it was 85-

Online RAFster122s

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Re: 1973 CB350F "Modest Original" build
« Reply #603 on: February 03, 2017, 12:43:44 AM »
He may have installed a kmh instrument to achieve his 80...
He had issues with math or truth...take your pick.  Bet he could tell a mean fishing story too!
David- back in the desert SW!

Offline SOHC4 Cafe Racer Fan

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Re: 1973 CB350F "Modest Original" build
« Reply #604 on: February 03, 2017, 06:05:07 AM »
He may have installed a kmh instrument to achieve his 80...
He had issues with math or truth...take your pick.  Bet he could tell a mean fishing story too!

If he was retelling riverfever's squirrel hunting foray, the squirrel would have been the size of a Sasquatch.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #605 on: February 03, 2017, 02:42:09 PM »
Haha! You guys are crazy, will be hard to test those speeds in downtown Manhattan!!  She feels quick all right, and a damn nick quicker than when she came in!

Offline grcamna2

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Re: 1973 CB350F "Modest Original" build
« Reply #606 on: February 03, 2017, 03:54:08 PM »
Haha! You guys are crazy, will be hard to test those speeds in downtown Manhattan!!  She feels quick all right, and a damn nick quicker than when she came in!

Wait til the weather gets nice and take a good blast on the Interstate.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #607 on: February 20, 2017, 08:46:02 AM »
Morning folks!  Back from a couple week trip.  I am dying to get this motor put back together.  Time to get cleaning!

Offline MoMo

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Re: 1973 CB350F "Modest Original" build
« Reply #608 on: February 20, 2017, 07:58:12 PM »
Vacation?   ...Larry

Offline grcamna2

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Re: 1973 CB350F "Modest Original" build
« Reply #609 on: February 20, 2017, 09:50:57 PM »
Glad to hear you back Atlas.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #610 on: February 28, 2017, 07:29:41 AM »
Vacation?   ...Larry

Was intended to be...but got sick..turns out wisdom teeth infected and have continued to give me the same recurring cold for the past few months..yikes!  Getting them yanked Monday and not looking forward to it...

Glad to hear you back Atlas.

Good to be back!  Had the power washer off and finished up the bottom half.  Couldn't for the life of me get the wiring harness portion off (I am pretty sure it is some sort of oil sender unit).  Tip-toed around it.  Whats next?


Offline grcamna2

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Re: 1973 CB350F "Modest Original" build
« Reply #611 on: February 28, 2017, 07:53:12 AM »
Atlas,
I would wash out the inside lower case passages completely w/ solvent before final assembly just in case any stuff from the outside of the case got shot up inside the inner oil passages when you pressure washed it.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #612 on: February 28, 2017, 08:34:18 AM »
Atlas,
I would wash out the inside lower case passages completely w/ solvent before final assembly just in case any stuff from the outside of the case got shot up inside the inner oil passages when you pressure washed it.

Yes!  Above was my "before" picture.  The pressure washer has a cool feature where you can mix in soap while you spray.  Neat!  As far as reassembly I guess my next steps are all those dreaded gears...yikes!

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #613 on: February 28, 2017, 10:29:38 AM »
I may rebuild the head today as that is sitting ready.  Anything I can should do with this clutch?  I know you all recommended sanding the disks down on some plate glass.  Anything else?  Could be a good evening project...



Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #614 on: March 02, 2017, 07:44:04 AM »
Sigh just when I think I have some time to work on my own projects!!



This CB750 Four came in in need of some help.  It is a friend of the owners of the CL350 so I said we'd take a stab at it.  She is mostly all there, or at least was for a majority of it's life.  It went in to some other shop for adjustments and came out with pods (K&N at least), megaphone exhaust, and 115 mains, much to my dissatisfaction - though I of course understand given the $$$ of a new stock exhaust!!

Anyways, she was getting 40mpg now we're at 19-20.  Would a change from 105 mains to 115's account for THAT much of a fuel economy difference?  After 10ish minutes or when she's full temp the revs start to soar, no tach but I'd guess 4,500rpm idle.  I haven't taken it out yet so I can't say much about how it's performing through the rev range.

My first thought was to look at the choke - not making that mistake again!





Luckily (or sadly?) it, and it's owner, were both operating correctly.  Throttle slides functioning as well.  Along the sides of each carb intake there are shiny marks.



I originally guessed this was someone a little to dremel happy getting in there and widening something, but after seeing similar marks on all 4 carbs I believe they are actually factory.  The owner says he's been messing with the idle etc to try to get it to play nice.  My first step will be to put it back to a base tune and see where we stand there. 

When the bike first came in hot I pulled out my IR thermometer to see how it was running.  The CL350 was only running on one.  Luckily #1, #2, #3, and #4 were similar temps.  #1 20° colder and #4 about 10° colder, I attributed this to them being the outer two cylinders.  Upon closed inspection the spark plug lead on #1 was completely loose.  The little tab which applies tension to the top of the spark plug had fallen out.  Instead of being a "D" shaped hole this one was just an "O".  I am sure the others are weekend as well and not holding with sufficient force.  The #1 cylinder was most likely missing maybe 10% of the time, but I'll have to take it out for a ride to confirm that.  Anyways it seems at least new plugs are in order.  Are these resistance plugs like the manual?  And the coils, two coils on this bike?  Removable spark plug leads or no like the CL?  I will download the manual (I believe it is the the section here on the forums) and do some digging of my own. 

The left exhaust is completely sooted up while the right is bone dry.  That I will have to dig in to.  I will also check to make sure we are in timing before going too deep elsewhere.

Anyways....always something!  Hopefully this one doesn't take too long and we can get back to my 350 Four.  I have decided to get a handful of my engine parts cleaned the machine shop where we have the B20 head.  I am thinking walnut shells.  So that will be good progress while I am working on this!  At least the 750 is a Four so maybe you all will enjoy  8)

Offline grcamna2

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Re: 1973 CB350F "Modest Original" build
« Reply #615 on: March 02, 2017, 09:52:08 AM »
Looks like a 'fun' project for you Atlas  :D I guess if it was mine the first thing I would desire(imo)would be to re-install the stock airbox an 'in box' Uni-filter,even though that won't fix the other problems.I hope your coils are evenly strong.
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #616 on: March 02, 2017, 11:54:39 AM »
Looks like a 'fun' project for you Atlas  :D I guess if it was mine the first thing I would desire(imo)would be to re-install the stock airbox an 'in box' Uni-filter,even though that won't fix the other problems.I hope your coils are evenly strong.

Agreed, this was my recomendation.  But that wouldn't be wise to do with the 115 main, correct?  Would want to put that back to stock which (correct me if I am wrong...) is 105.  But would still need to jet up for the exhaust, correct?  Thanks grcamna!!  Good to hear from you.

Offline iiAtlas

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Re: 1973 CB350F "Modest Original" build
« Reply #617 on: March 09, 2017, 09:27:26 AM »
Now this is weird...



Idle mixture jets filled with...solder?  Compare to ones from a rebuild kit.





Who would do this?  Is this some weird "fix" to make the bike run less rich?  I have never seen anything like this - what about you gurus?  Is this some sort of "underground" mod I am not aware of?  My first instinct is to dive in and rebuild these carbs, or at least swap the idle mixture screws out with non-plugged ones...



The bike has 115 mains with megaphone exhaust and pod filters.  We have the OEM airbox with a new K&N filter.  Should we rebuild and keep pods + megaphone and keep the 115 mains? Or rebuild, swap the pods for the stock airbox + k&n filter, keep megaphone exhaust but step back down to 105 mains?

Any input greatly appreciated!  I just had my wisdom teeth pulled and have been stuck in bed until today....