'73 CB350 Build Thread

Hello all! First legitimate post on DTT. I hail from the "Nasty-Nati" and have always been interested in cafe's. I've been a Honda guy my entire life and have built a number of different rides, but have never once ventured into the 2-wheeled-world. I had a '99 EM1 Si which I sold for my '00 S2000. That got totaled, so I bought another one in the same color, year, etc., just with less miles. Anywho, Im always surfin' the net for cafe projects, and my wife asked me "when are you going to get one of those?" which put the process in motion.

A week later, we came home with this hog!


My wife jumpin' on the bike for a glamour shot. <3 her!


My not-nearly-as-attractive-mug


The bike has good bones. It kicks over, but doesn't run. Has minor surface rust on just about everything. Paint is in piss-poor shape, seat is torn, throttle cable sticks, etc. Order a ton of replacement parts including:

- New Battery
- New Throttle Cable
- Carb Rebuild Kits
- Carb stainless fastener kit
- 4ea OEM exhaust pipe joints
- New seat cover
- JIS screwdrivers
- Impact screwdriver

Let the fun begin! Now, full disclosure, I can assure you of the following:

- I will make stupid mistakes, but I will only make them once
- I will ask stupid questions, but I will only ask them once
- I will not always know the name for parts, so you'll have to interpret often
- I will only ask questions if I can't figure out myself first

That said, here we go! Tonight I was able to get the bike apart pretty much. Took the exhaust off and installed the 4ea new exhaust pipe joints. That was easy enough!

Before - Note the janky exhaust, loosely installed, loose exhaust flange, blah blah blah:


After - Pic sucks, but my camera died so this is taken with a potato.


Question #1 - Note the "before" pic has pass. footpeg installed in a dangling fashion. Now, when I installed everything correctly, I noticed the muffler, which I believe to be aftermarket, is too close to the mounting holes for the pass. footpeg. Could I remove the "L-tab" on the footpeg and install it upside down? Otherwise there isn't enough clearance and it gouges the mufflers.

Idiot moment #1 of 1,000,000

- I could not for the LIFE of me figure out how to remove the throttle cable from the carbs. /facepalm After incessant googling, forum searching, hair-pulling, beer-drinking, etc., I twisted the cable and out came the peg. I felt SO stupid.

Anyways, carbs are off, rebuild (hopefully) coming tomorrow!

Welcome, Matt! Nice to see you made it over here from the Cincinnati Cafe racer page on FB. Lovely wife, nice looking bike. You = not so much . I look forward to seeing your progress and seeing the bike in person soon. Congrats and best of luck.

I'm trying to get the primary and secondary main jets out of the carb and the bigger of the two will not budge. The guide I'm following says to pull them out with your fingers, but there's no way the main jet is moving. Any ideas? Is it safe to use needle nose to pull it out?

What's the best way to clean the internals of cb350 carbs? Soak in vinegar? Pinesol?

mattfeet said:

What's the best way to clean the internals of cb350 carbs? Soak in vinegar? Pinesol?

Click to expand...

The "best" is an ultrasonic bath, but you would need someone with one to do that. Failing that I stripped my right down and soda blasted them.

Without any of these I'm sure carb cleaner or a carb bath would work but then you may be the same money taking it to a mechanic with an ultrasonic bath and getting them to dump it for you.

Hi welcome onboard nice start mate good project bike good to have support from the missus. Ime the same when up to ya elbows in it she will be there with a cool beer on a hot day ( not many of them here in the UK haha) usually a warm brew and a good listener when all she heres is probably blah blah blah ??? carbs i stripped as far as they would without damage then soaked them in a bowl of carb cleaner then wd 40 ( penatrating oil) took 24hrs but came apart easy then plus they came up clean ,some bits take time but i couldnt wait have learned to (steady away ) now on my first build but found this site invaluable for ideas n answers am all ears mate if ya need help or inspiration good luck will follow ya build

just a suggestion, but you can upgrade to some "brand new"32mm mikuni's for $250 good price I thaught, manifolds to suit $40 and cable set up around $40, thats $340 total not bad I reckon.
http://www.speedmotoco.com/ProductDetails.asp?ProductCode=029%2D312&CartID=2
http://www.speedmotoco.com/ProductDetails.asp?ProductCode=002%2E053&CartID=3
http://www.speedmotoco.com/ProductDetails.asp?ProductCode=029%2D332&CartID=7
and if you minus the cost of the throttle cable, carb rebuild kits and the stainless carb fastener kit you mentioned you needed for the originals it wouldn't work out that much more.

Thanks for the suggestion, but I think Im going to stick with what I've got. This is still somewhat of a "budget-build" but I might go the Mikuni route at some point in the future.

Went out and picked up a bunch of cleaners, tools, hammers, etc., tonight after disassembling the left carb today. Everything went pretty well. This week is going to be cold again in Cincy so Im sure progress will slow down a bit.

More pics coming tonight!

-Matt

Sexy! Oh, and the bike looks pretty good too.
-Ironmom

Matt good to see you made it and are making some progress.

I'm on board, keep the updates coming.

GK

Today I tore into the carburetors after getting them removed last night. Just got around to disassembling the left carb today because I wanted to take my time, make notes, take a ton of pics, etc., so I know I could put it all back together. Im really happy I went ahead and order a new stainless steel carb bolt kit since one of the screws over the diaphragm is nearly completely stripped and a number of other are extremely rusty.

Float chamber cover off. TONS of gunk and garbage in here. Can't wait to get these all cleaned up:


Diaphragm cover off. Spring and diaphragm assembly removed:


The main jet was a total PITA to remove. I need to call in some liquid courage to get it out!


To the dude who made the CB350 carb rebuild DIY, next beer is on me!


The idle screw was almost seized in the hole. Question #2 Should I replace the idle screw or will the existing work ok after a small cleaning?


The float assembly hinge pin took some more elbow grease to remove. Once all the gunk is removed, it should slide in nicely, easy, and tight. (That's what she said!)


Question #3 Do I need to somehow remove these jets, outlets, whatever-they-are, before cleaning everything?


Question #4 What's the best way to remove the rust found on the diaphragm cover and other small areas which, I believe, were originally chrome plated?

Also, a sneeze or earthquake would have been bad news once I got all the parts out!


That's all for tonight!

-Matt

Top work, as I am on a budget aswell you have made me feel guilty for trying to take the easy way out, think I might have a crack at mine aswell, can't seem to find that carby rebuild thread though, could I be a hassle and ask for a link to it. 8)
Cheers Sean.

No problem! http://cb350.blogspot.com/2007/05/carb-rebuild.html

-Matt

Hi Matt, and welcome.

I replaced the idle air screws on my 360, but they came with the carb rebuild kit, so why not? However, as others on this board have pointed out to me, the idle air screw springs that came with the carb are better than the ones that come in the rebuild kit, as the ends of the springs are ground flat so they don't chew up the carb body or the idle air screw.

I don't know about removing the jets, but as for the diaphragm cover, you can purchase replacement chromed covers. Or, you can clean yours up and prime and paint them. That's my plan for the covers on my 360.

Have you soaked the carb bodies yet to get the muck out of them? I use the PineSol method (4 parts PineSol - 1 part very hot water, soak), but you must have all the rubber out of the carb because the PineSol eats some kinds of rubber. Other folks have had good luck with the lemon juice boil, the previously mentioned ultrasonic cleaner, regular carb dip, and so on.

Good luck!

I appreciate the reply!

I BELIEVE all the rubber parts are out of the body. What else is there besides the rubber stopper and diaphragm? Is there anything left in the carb that I somehow didn't get to? I will be soaking the bodies either tonight or when it warms back up. Freakin' 36* here today.

-Matt

mattfeet said:

No problem! http://cb350.blogspot.com/2007/05/carb-rebuild.html

-Matt

Click to expand...

cheers thanks Matt

mattfeet said:

I appreciate the reply!

I BELIEVE all the rubber parts are out of the body. What else is there besides the rubber stopper and diaphragm? Is there anything left in the carb that I somehow didn't get to? I will be soaking the bodies either tonight or when it warms back up. Freakin' 36* here today.

-Matt

Click to expand...

I'm not familiar with the carbs on the 350s, but it does sound like you've got everything out. If you get a sealed container (like a small Tupperware shoe storage bin), you can even soak them inside. Otherwise, things will smell so piney fresh your eyes will water!

Roger that.

so now DTT is turning into CSi all the sudden?! haha. No one here knows what an EM1 is except you, me and Chris! I'll follow the build on both forums though. exciting to see your progress.




CSi OWNZ J00