Topic: Honda 1972 CB350 FOUR RESTAURATION (BELGIUM)

[Belgianbastard]

Hi guys

I'm a belgian engineering student and i'm new to the bigger motorcycle scene.
I already restaurated a honda monkey 50, honda SS 50 and I still own my Honda Dax ST50 from 1972.





Now i bought myself a Belgian CB350 Four 1972 in bad shape from an old man.
The keys are gone, and the engine hasn't worked the last few years.

First thing on my list is getting the engine going, the rest is the same like restaurating the mini-bikes, but the engine is more complicated because the minibikes only have 1 cilinder and a million of spare parts everywhere online.
Is there a sort of ignition-scheme on this forum I can follow from the kickstart untill the engine going?

For example, is it possible to just shortcut the key-wires so the key is "always in" and i don't need a key at this moment?
And is it possible to start without battery, just kicking it? How do i know my ignition-wheel is still in good enough shape to start?
All things that were much easier with them little bikes...

My first plans:
-Shortcut the key-wire
-Cleaning the carbs (any tips?)
-Change the oil
-Remove all rust from exhaust, engine, pipes, wheels,...

Once that engine is going, the honda wires and electric output will guide me to all the other stuff

Thanks for the help
Gratz
Jonas

[calj737]

You can "hot wire" the bike to start, but it's not advisable for 2 reasons:
1- it will drain the battery because you have no means to interrupt the direct power from switched power.
2 - it will make stealing your bike very easy

Having said that, here's the color wiring diagram for your bike:
http://manuals.sohc4.net/cb350/technical_reference/WD350400.pdf

You will see the KEY switch has 4 wires running to it; RED, BLACK, BROWN, AND BR/WHITE.
RED is wired from the key, thru the main fuse to the POS on battery
BLK becomes "switched 12v" when the key is moved to position 2
BROWN and BR/WHT also switch and deliver gauge lighting, tail light power, etc.

For the purposes of testing only, you can jumper BLK to RED at the main fuse, key side. But you will be drawing power always form the battery.

As for cleaning our carbs, check the FAQ section of the forum, and here's the manual for your bike. Perform the 3,000 mile service recommended to get the bike in proper operating condition.
http://manuals.sohc4.net/cb350

[dusterdude]

Welcome and good luck

[calj737]

... and good luck

Is that a dig on getting useful help from me, Dusty? 

[dusterdude]

Damn,you got me cal

[Belgianbastard]

You can "hot wire" the bike to start, but it's not advisable for 2 reasons:
1- it will drain the battery because you have no means to interrupt the direct power from switched power.
2 - it will make stealing your bike very easy

Having said that, here's the color wiring diagram for your bike:
http://manuals.sohc4.net/cb350/technical_reference/WD350400.pdf

You will see the KEY switch has 4 wires running to it; RED, BLACK, BROWN, AND BR/WHITE.
RED is wired from the key, thru the main fuse to the POS on battery
BLK becomes "switched 12v" when the key is moved to position 2
BROWN and BR/WHT also switch and deliver gauge lighting, tail light power, etc.

For the purposes of testing only, you can jumper BLK to RED at the main fuse, key side. But you will be drawing power always form the battery.

As for cleaning our carbs, check the FAQ section of the forum, and here's the manual for your bike. Perform the 3,000 mile service recommended to get the bike in proper operating condition.
http://manuals.sohc4.net/cb350

Wow thanks for the fast reactions, those manuals were just what i was looking for!
Shortcut is only to test and get the ignition going, I think the best way for me is then just to buy a new keylock + key and replace the old one instead of manufacturing a new key that fits the lock (if that's even possible after all those years).

Let's hope the guy didn't stop riding because the electricals are rot and a spider web, but I'm afraid it will take a while before a will get the engine going.

Let's have some electrical fun!


 

[calj737]

A replacement key is available actually. On the backside of the ignition, there's a small number stamped into the "cylinder" housing. This is the key #. Take it (the number or the whole ignition lock) to the dealer with some proof of ownership, and get a new key. That way it's still usable for the seat, fuel filler, etc.

[Jore]

Here's an interactive wiring diagram where you can select parts of the wiring to shut off and it's easier, at least for me to follow:

http://oldmanhonda.com/MC/wiring350F.html

[SOHC4 Cafe Racer Fan]

If you know the key code, there are also people who can provide you a pre-cut key on-line without the registration.  http://hondakeys.com/ is one of these vendors.

[Belgianbastard]

Wow thanks for this massive help guys, the four community isn't that big here in Belgium, a bit in the Netherlands but that's it.
It's going to be a project at a student budget, so don't expect me to get it all chromed and welded out, first I want it to ride good, and then slightly on change the rest.

I want to redo everything from the Fuel to the engine, and from the starter to the engine
1) Clean out the fuel tank and remove eventual rust inside
2) Check the fuel lines for replacement
3) Take the carbs off, clean them and put them back
4) Clean the airfilter
5) Replace the spark plugs
6) Install a battery
7) Replace the oil
8 ) Measure out the voltages and try to start it
9) Synchronize the carbs when it starts
10) Adjust the valves interspaces

Ok the key is ordered

I was looking on “David Silver Spares” because they’re cheap for postage to Belgium
Shoppinglist contains all the basic stuff I think I’ll need to get going and try to get ignition and check up with the state of the engine:

Aftermarket Battery CB12AA
4x Spark plugs, is  NGK DR8ESL a good choice or doesn't it matter so much on these bikes?
Motorex carb cleaner 500ml
Motorex 10w40 semi-synth oil 4l

But I’d want some other parts I can’t find there
-Cheap Carberator Synchronizer kit
-Product to clean my rusted wheelspokes, exhaust etc
-Cheaper Battery charger (the one on the site is €60 and I only have this bike with battery..)
-Fueltank inside cleaner (against the possible rust above in the tank)

Somebody knows a site that can offer me some of these cheaper solutions too?

Can't wait to get started! 

Gratz
Jonas

[calj737]

You can use vinegar to clean the rust from inside your tank. Also probably use it on a cloth to wipe and scrub off the rust on your spokes and exhaust. Be aware, it's acid-based and will not stop dissolving the rust only but will eventually attack the metal. Rinse the tank afterwards with Baking Soda and water to neutralize and follow with gas/oil mixture to prevent flash rusting.

[flatlander]

lidl or aldi sometimes have the battery charges for pretty cheap. or check www.conrad.be they might have something.

for removing rust on the cheap you can use cola and alu foil, then usual chrome polish:
http://forums.sohc4.net/index.php/topic,134863.msg1524111.html#msg1524111

carb sync tool: http://www.carbtune.com/
or try finding one second hand?

oh and... good luck

[carnivorous chicken]

Didn't see that anyone answered this, so here goes: the bike won't start without a battery or with a dead one, even kicking it.

I would also add: put a few drops of oil down each plug hole before you start to kick it over if it's been sitting for a while.

Great bikes, good luck!

[Jore]

If you have a battery charger, you can use it to clean the inside of your tank with electrolysis, it's really easy to do:
http://www.instructables.com/id/Electrolytic-Rust-Removal-aka-Magic/

After doing that I used acetone to displace all of the humidity still trapped inside the tank, it works, but you have to keep it full of fuel or at least coated with something like 2 stroke oil and gas or else it will start to rust again. I ended up lining the tank with some epoxy stuff.

As for the plugs get also the boots for them, on the 400 they're 5k in resistance, don't know if it's the same on the 350.

If you're taking off the carbs, clean them and do a bench sync on them before putting them back on, pm me and i'll send you a guide someone made for servicing the carbs on the 400. On the 400 at least connecting the airbox to the carbs is a lot easier if you stick a bicycle inner tube inside the airbox, line up the ports with the carbs and them fill up the tube.

[Belgianbastard]

Here  it is, i've been disassembling a lot of things more then you see on the picture (taillaight, footrests, airbox, carbs, horn, brake/clutch handles, winkers,..)
But i have a problem with a few parts:

1) The seat is locked and i can only unscrew 1 of the 2 bolts holding the lock, the other one is just not reachable, there's no other way than wait for a new key from a honda dealer i think? Hopefully it will fit
2) my speedometer is rusted above (at the meters) and on the downside, the head of the philips-screw to unscrew is is totally #$%*ed, so i can't get it of, and because of this also not the front mudguard. How do i get it out without damaging the interior so i can screw a new one on?
3) My rims are already a bit less rusty with the coca-cola and aluminium foil but i still have a lot of work, but the spokes are so rusted, do i ever get them shiny again or just paint them black after cleaning the rust?
Want to do most of the work now because i can only work outside, and in the winter it's cold here in Belgium

Thanks!

[marting100]

Nice bike!
only advise I can give you now is, dont rush it. I understand winter is coming and you want to do a lot
before winter (same here in Québec) but trying to do too much too fast will not help you on the long run.
This is a project bike, sometime one rusted/stripped bolt will take you 30 minutes to take out, take your time, focus on one thing at the time and move on.
You can easily bring the carbs, wheels, motor inside for winter and work on them.
Good luck and have fun!
M

[calj737]

The screws are not Phillips, they're JIS. Very differ shape and taper. Buy some JIS bits and an impact driver (hammer actuated type) and the screws will come out more easily

[Belgianbastard]

Nice bike!
only advise I can give you now is, dont rush it. I understand winter is coming and you want to do a lot
before winter (same here in Québec) but trying to do too much too fast will not help you on the long run.
This is a project bike, sometime one rusted/stripped bolt will take you 30 minutes to take out, take your time, focus on one thing at the time and move on.
You can easily bring the carbs, wheels, motor inside for winter and work on them.
Good luck and have fun!
M

Thanks!

The carbs are full of fuel and dirt from 20 years old, the spokes are as rusty as can be, some are bent and the electricity is like a rat's nest where a battery leaked on
so I won't be bored when it's cold outside 
The problem is everything comes off so slow, for example the screw at the bottom of the speedometer looks like this :


It's messed up very deep, like a lot of the other screws i found
But here it's in a housing, and it's ruined so deep that I can't drill a slice with my dremel because I'll damage the housing around it very bad, and that's very visible..
It's like the last owner tried every bolt without any WD40 nor patience, totally ruined all the heads and then decided to sell it

[marting100]

I know what you mean, when I got my bike the 2 1st bolts I tried to take out took me 1 hr, from there I knew what to deal with  ... sometime someone problem become someone else pride and joy (after lots of work and patience that is 
You can always try some bolt extractors along with some liquid wrench and lot of patience (patience is the only thing you cant buy)
Cheers!
M

[Jore]

I've had better luck with left hand drill bits compared to the screw extractors

[Belgianbastard]

This weekend I hope I'll get to the point of disassembling the engine from the frame, i'll clean the oil, the outside etc but I don't know if I'll need to replace something.
The engine doesn't run anymore but I think it's 90% the fault of the carbs that were very nasty
The engine has 35.000 kilometers, what do you guys think I should replace inside?
I haven't worked on any 4 cylindre ever before so it's totally new for me, but I won't ride it untill next summer so have a lot of time to learn
The best shot for me will be opening it up and taking pictures and asking questions i guess? 

Thanks in advance for all the help guys!

[Jore]

To remove the engine I did it like in this video:

<iframe width="420" height="315" src="

frameborder="0" allowfullscreen></iframe>

It's pretty simple and a one man job if you have no one around to help you.

[Belgianbastard]

I started taking the carbs apart, already cleaned the outside with coke and toothbrush, but also inside they are soo filthy
The whole bottom of the reservoir has a cristallized layer on the tubes where the jets are screwed in, I suppose the fuel inside totally vaporized over the years

Second problem: I have 2 carbs where the needle doesn't lift when I pull the throttle
I can pull it up a few mm's and then it feels like it's stuck somewhere
The needle never lifts and makes not even a small slit

[marting100]

If you don't have one already, get yourself a manual (Honda workshop, Clymer) I have downloaded the 350F - 400F workshop manual from this site (http://cb400f.webs.com/maintenance), it will show you how to take apart your carbs to clean them properly. You also want to search the forum (and Youtube) and find lots of guys that have done it with all sort of cleaning methods. When I did mine, I took all the jets and needles out and clean them in a small ultrasonic bath (with pine sol and degreaser (Zep) that I have purchased on eBay from china for 30$. Clean all passages and jets with carb cleaner and compressed air. Make a good inspection and clean off any gas varnish or old gasket residues with a small brush and sharp knife. Replace all gasket and o-rings and reassemble everything. Take you time, better to do it right the 1st time 
M

[Belgianbastard]

Winter is coming and I want him to be totally apart so can work on every piece separtely inside the warmth and put it back together in the spring
Speedometer is still stuck on front weel, so is the rpm cable on the engine connection, so we'll need to drill them out

I let the oil pan leak out and opened it, the oil was pitch pitch black, on the bottom of the pan i found some solid material
I hope it's just old oil and dirt, and not scrap metal, how can i know if this is a bad thing for the engine's insides?

My seat is also curled up like a banana, had a big cut in the seating, and the chrome side bars start to peel a bit off
Is is possible to fix this all? Or just better to just search a donor seat
I found a lot of seats on ebay but the shipping to Belgium makes it always way too expensive
Or are there good new seats available that look very similar (have no problem with quality aftermarket seat)

I'd like to go like this style, very clean and classic: