1974 Honda CB350F | 1st Build

[ichitz]

Hey all!


I've been lurking for a couple of months and this site inspired me to work on my bike.


I bought a '74 CB350F recently. It's actually my first bike even though I've always wanted to ride a motorcycle growing up, and never got a chance to. Did own a scooter at some point but that's completely different


I have plenty of experience on bicycle repairs, but engines and carbs are like aliens to me. Meaning I have a lot of studying to do and I'll probably have some extremely noob questions so please bear with me. I'll try to post noobish dumb questions in the 1800cafe help section.


Here's how the bike is right now as I got it.

She's in pretty good condition. Everything seems to work, the electrical system is fine, etc.


Living inside the New York City tri-borough means I don't have the luxury of having a garage to work on. I live in an apartment. So I think I'm going to start with reeeeaaaaaaaaal baby steps first like swapping out the bars, modding the seat, etc. Then come winter I could probably put it in a shared garage in a mechanic's shop and use their space to work on the rest of the bike that would require me to disassemble and reassemble things.


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WHAT I AM GOING FOR:
A cafe racer 'style' bike with 2 up seat.


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INSPIRATIONS:

Somehow I really dig this worn out, faded looking paint job.

And i'm liking the look of this seat.

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THINGS TO DO:

• There is only one serious problem I ran into currently. She is having trouble going over 50mph. Reading around, it's the exact same problem as whataulooknat have in his CB450 won't hit the ton anymore thread. So from what I gather, it could be carb timing or worn diaphragm. I'm not sure. I actually never noticed until today since you can't go too fast riding in/around new york city due to traffic. So whatever this is, I need to fix this. Half a ton just won't do
• Check spark plugs
• Clean and check carbs (float, points, compression)
• Check ignition timing
• Check/cleanup air cleaner
• Handlebar swap. I'm thinking clubmans
• Cut down and reupholster the seat
• Shorten/Chop off rear fender
• replace the big ol'stock tail light
• replace with smaller turn signals

winter time:

• cleanup engine (?)
• paint job

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NEED TO BUY:

• carb vacuum gauge kit
• carb rebuild kit (?)
• front tire
• smaller turn signals
• spark plugs
• spark plug wrench
• spark plug gauge
• carb cleaner
• bottle of compressed air
• clubman bars
• new grips
• lucas tail light

 

[joeyputt]

Welcome Brother! Congratulations on your first motorcycle as well, she is very nice! There are a lot of great people here that are more than happy to help.

 

[Big R]

Joey is right: nice bike to start with!

Along with cleaning the carbs out, be sure to adjust the valves as well. Actually, all the maintenance items should be gone over first: fresh oil, clean air filter, brake pads/shoes/fluid, fuel filter, timing/points, etc. After all, this is a vintage bike.

After all that is done, get a compression tester and double check all 4 cylinders. Better to have an idea of any problems before you start really working in the motor!

 

[ichitz]

Thanks guys.

You're right. I should start with the maintenance. It's just that having never worked on anything motor related before makes the whole process kinda daunting. But I just read some more articles and watched a bunch of youtube vids and it seems like, as far as carbs go, I should be able to take it apart, clean/check for problems, and put it back together. Hopefully I can figure out why she can only do a half ton now :'(

The oil is fresh, that I'm sure of. The other stuff I'm not sure. I'll add all that you said to my to-do list

 

[surffly]

those carbs dont have CV diaphrams.

get and OEM manual and go over the basics
-get compression numbers
-new points
-new plugs
-clean the carbs
make sure the right jets were used with the after maket pipes
cant tell if it has pods....pods make everything run like poop
-make sure you are getting spark to all the plugs
-fresh oil
-fresh gas
-adjust valves
-check for air leaks at the manifolds...this is common on these bikes

sounds like a lot but its really not that bad. they are all quick jobs and go fast when you have the right tools.
cant really help that much with out knowing all of the details(the results from those tests)
with out the whole picture you cant be sure whats effecting what.

 

[ichitz]

I'm waiting for some parts to come before I take the carbs out to clean up and check for problems. The thing with street parking in new york is that there's weekly alternative street parking where I have to move my bike to the opposite side of the street and back again so I can't really disassemble before everything's here and I'm all prepared. Sucks... i want a garage.


Anyway before I go into all that. I got a couple of noob questions I'm hoping someone could help me answer.


1. What size spark plug socket would I need to take out my spark plug? The NGK D8EA is the spark plug on there now, which I know that it is 12mm thread diameter. But I can't seem to find the socket diameter. I'm assuming it's such a simple thing that everybody knows, but I'm a big noob.


2. When I start my engine, I have to start it with the choke on. It starts on the first try. But after that, if I don't continue to pull slighty on the throttle, the engine would die. If I let it run and warm up for a couple minutes, then the engine has no problem staying idle at around 1200rpm, which is the ideal idle rpm in the manual. But why wouldn't the engine stay idle initially at the first start? I'm lost..

 

[Big R]

1) the one that came with the toolkit. Sorry, that's the one that I'm lucky enough to have.......

2) are you opening the choke right away? The choke should be shut for start up, the after it warms up a bit, then open the choke a little. After about 10 minutes or so you should be able to open the choke completely.

 

[surffly]

where in the city are you? there are a few shops that i know of that will let you work on your bike, but why tare it all down?

 

[Kanticoy]

I'm waiting for some parts to come before I take the carbs out to clean up and check for problems. The thing with street parking in new york is that there's weekly alternative street parking where I have to move my bike to the opposite side of the street and back again so I can't really disassemble before everything's here and I'm all prepared. Sucks... i want a garage.


Anyway before I go into all that. I got a couple of noob questions I'm hoping someone could help me answer.


1. What size spark plug socket would I need to take out my spark plug? The NGK D8EA is the spark plug on there now, which I know that it is 12mm thread diameter. But I can't seem to find the socket diameter. I'm assuming it's such a simple thing that everybody knows, but I'm a big noob.


2. When I start my engine, I have to start it with the choke on. It starts on the first try. But after that, if I don't continue to pull slighty on the throttle, the engine would die. If I let it run and warm up for a couple minutes, then the engine has no problem staying idle at around 1200rpm, which is the ideal idle rpm in the manual. But why wouldn't the engine stay idle initially at the first start? I'm lost..

Spark plug socket size is 18mm. You can get them at an auto parts house. You will need an extension on it to get the two middle plugs out.

The choke thing is normal. These bikes are extremely cold natured on the first start up of the day. It gets worse when there is no air filter, or the air filter has been changed, so check that first and foremost. If it runs well at 1200 after warm up, it sounds pretty well sorted, that's where it should be, Run a little sea foam through the gas at fill ups and it will help flush the motor of whatever might be in there from sitting, etc.

Make sure the cam chain stays adjusted, This is the Achilles hell of the baby 4s. You'll see how to do it in the manual, which you can get for free here:

http://dl.dropbox.com/u/19494889/CB350F%20CB400F%20Shop%20Manuals%20Part%20Lists%20%26%20More.pdf

Just save and open.

 

[ichitz]

Thanks guys!
I just realized i wrote it wrong. What i meant was the the choke needs to be on the OFF position, then slightly hold onto the throttle for the engine to stay on. Takes at least 2 min until the engine can manage to stay idle.

Anyway, if that's normal then that's great. Thanks a bunch for that PDF manual! I only got the Clymer manual. The shop manual def has more detailed illustration and directions.

 

[Traveler350]

Hey dude. Hows it going? Are you still in the city?